Hello,

I have a garden retaining wall that seems to never dry out. The wall
is constructed from bricks with three stretcher courses and then one
header course repeated through its height. The wall is two courses
deep with what looks like a thin cavity inbetweeen. Two thirds of the
wall is below ground, the other third is above ground. At the bottom
of the wall there are some spaces in the mortar, presumably weep
holes.

What puzzles me is why is the whole wall damp, even the part that is
totally above ground? Any moisture coming from the earth that is
retained would I guess fall down the cavity and out the weep holes, so
I can't believe it is coming from there.

Next to this garden wall is part of the house wall, this is dry, so
not damp from rain penetration. So maybe the whole garden wall has
rising damp, but why not the house wall?

And after reading this article I am doubtful that rising damp even
exists:

http://www.architectsjournal.co.uk/n...204095.article

This is really bugging me, I would really like to know the cause of
this damp!

Thanks,

Graham

Graham Jones wrote:
Hello,

I have a garden retaining wall that seems to never dry out. The wall
is constructed from bricks with three stretcher courses and then one
header course repeated through its height. The wall is two courses
deep with what looks like a thin cavity inbetweeen. Two thirds of the
wall is below ground, the other third is above ground. At the bottom
of the wall there are some spaces in the mortar, presumably weep
holes.

Part of that statement isn't clear, weep holes are usually just above ground
level (but in high walls, there can be more than one course of them) and not
two thirds underground, Is all the wall (except footings) exposed on your
side, and the ground level behind that rising two thirds up the wall?

What puzzles me is why is the whole wall damp, even the part that is
totally above ground? Any moisture coming from the earth that is
retained would I guess fall down the cavity and out the weep holes, so
I can't believe it is coming from there.

From what I read with the header and stretcher course description, you have
a solid 9" (one and half brick thick) wall and not a cavity, and as it is a
retaining wall, then you are correct, the holes at the bottom are there to
stop water pressure building up and pushing the wall over. Believe me, it
happens!

As for the damp, you don't say what the water table is, but there may be a
high one there, a small underground stream nearby or even a leaking
water/sewer pipe causing the wall to be damp.

Next to this garden wall is part of the house wall, this is dry, so
not damp from rain penetration. So maybe the whole garden wall has
rising damp, but why not the house wall?

The damp is probably not 'rising' but explained above. Now lets assume that
you are correct, then with the normal garden wall construction, there are
*NO* built in damp courses to prevent rising damp nor damp proof membranes
behind the wall to stop penetrating damp due to higer ground levels.

The house will have all sorts of damp proof membranes built it.

And after reading this article I am doubtful that rising damp even
exists:

In the wall it could well do (contradiction of what I have already said) but
if the water table is low down and near the footings, the wall will drag
that moisture up naturally - but to no more than around three feet in height
from the water table.

http://www.architectsjournal.co.uk/n...204095.article

This is really bugging me, I would really like to know the cause of
this damp!

Now you possibly know - but I'm sure other will have different ideas that
would also be possible.

Cash

On Oct 19, 8:52*pm, "Cash"
wrote:
Graham Jones wrote:
Hello,

I have a garden retaining wall that seems to never dry out. The wall
is constructed from bricks with three stretcher courses and then one
header course repeated through its height. The wall is two courses
deep with what looks like a thin cavity inbetweeen. Two thirds of the
wall is below ground, the other third is above ground. At the bottom
of the wall there are some spaces in the mortar, presumably weep
holes.

Part of that statement isn't clear, weep holes are usually just above ground
level (but in high walls, there can be more than one course of them) and not
two thirds underground, *Is all the wall (except footings) exposed on your
side, and the ground level behind that rising two thirds up the wall?

What puzzles me is why is the whole wall damp, even the part that is
totally above ground? Any moisture coming from the earth that is
retained would I guess fall down the cavity and out the weep holes, so
I can't believe it is coming from there.

From what I read with the header and stretcher course description, you have
a solid 9" (one and half brick thick) wall and not a cavity, and as it is a
retaining wall, then you are correct, the holes at the bottom are there to
stop water pressure building up and pushing the wall over. *Believe me, it
happens!

As for the damp, you don't say what the water table is, but there may be a
high one there, a small underground stream nearby or even a leaking
water/sewer pipe causing the wall to be damp.

Next to this garden wall is part of the house wall, this is dry, so
not damp from rain penetration. So maybe the whole garden wall has
rising damp, but why not the house wall?

The damp is probably not 'rising' but explained above. *Now lets assume that
you are correct, then with the normal garden wall construction, there are
*NO* built in damp courses to prevent rising damp nor damp proof membranes
behind the wall to stop penetrating damp due to higer ground levels.

The house will have all sorts of damp proof membranes built it.

And after reading this article I am doubtful that rising damp even
exists:

In the wall it could well do (contradiction of what I have already said) but
if the water table is low down and near the footings, the wall will drag
that moisture up naturally - but to no more than around three feet in height
from the water table.

http://www.architectsjournal.co.uk/n...ing-damp-is-a-...

This is really bugging me, I would really like to know the cause of
this damp!

Now you possibly know - but I'm sure other will have different ideas that
would also be possible.

Cash

Hello,

Thanks for your reply,

By two thirds underground I meant that two thirds of the wall retains
earth, the upper third retains nothing.

There definitely is a small cavity between the two skins, the bricks
are old imperial size, 2 x the width of the brick does not match the
length.

Graham

Graham Jones wrote:
On Oct 19, 8:52 pm, "Cash"
wrote:
Graham Jones wrote:
Hello,

I have a garden retaining wall that seems to never dry out. The wall
is constructed from bricks with three stretcher courses and then one
header course repeated through its height. The wall is two courses
deep with what looks like a thin cavity inbetweeen. Two thirds of
the wall is below ground, the other third is above ground. At the
bottom of the wall there are some spaces in the mortar, presumably
weep holes.

Part of that statement isn't clear, weep holes are usually just
above ground level (but in high walls, there can be more than one
course of them) and not two thirds underground, Is all the wall
(except footings) exposed on your side, and the ground level behind
that rising two thirds up the wall?

What puzzles me is why is the whole wall damp, even the part that is
totally above ground? Any moisture coming from the earth that is
retained would I guess fall down the cavity and out the weep holes,
so I can't believe it is coming from there.

From what I read with the header and stretcher course description,
you have a solid 9" (one and half brick thick) wall and not a
cavity, and as it is a retaining wall, then you are correct, the
holes at the bottom are there to stop water pressure building up and
pushing the wall over. Believe me, it happens!

As for the damp, you don't say what the water table is, but there
may be a high one there, a small underground stream nearby or even a
leaking water/sewer pipe causing the wall to be damp.

Next to this garden wall is part of the house wall, this is dry, so
not damp from rain penetration. So maybe the whole garden wall has
rising damp, but why not the house wall?

The damp is probably not 'rising' but explained above. Now lets
assume that you are correct, then with the normal garden wall
construction, there are *NO* built in damp courses to prevent rising
damp nor damp proof membranes behind the wall to stop penetrating
damp due to higer ground levels.

The house will have all sorts of damp proof membranes built it.

And after reading this article I am doubtful that rising damp even
exists:

In the wall it could well do (contradiction of what I have already
said) but if the water table is low down and near the footings, the
wall will drag that moisture up naturally - but to no more than
around three feet in height from the water table.

http://www.architectsjournal.co.uk/n...ing-damp-is-a-...

This is really bugging me, I would really like to know the cause of
this damp!

Now you possibly know - but I'm sure other will have different ideas
that would also be possible.

Cash

Hello,

Thanks for your reply,

By two thirds underground I meant that two thirds of the wall retains
earth, the upper third retains nothing.

That's what I thought you meant - thanks.

There definitely is a small cavity between the two skins, the bricks
are old imperial size, 2 x the width of the brick does not match the
length.

Too small to be called a cavity Graham, the construction would be two
'stretcher courses' side-by-side for about four or five courses or so up,
and then a 'header course' at right angles to these as reinforcing method
(if the wall is 9" thick, then it will be classed as a 'solid' wall [1]).

The variations in the brick sizes may cause two stretchers side-by-side to
be slightly smaller than the length of a standard 9" brick and the old
brickie would have made adjustments for this as he was building the wall -
hence the "thin gap" between them.

[1] Cavity walls are usually a minimum of 11" thick and all stretcher
courses (generally) - I.E. stretcher course, 2" gap, stretcher course.


Cash

On Oct 19, 9:34*pm, "Cash"
wrote:
Graham Jones wrote:
On Oct 19, 8:52 pm, "Cash"
wrote:
Graham Jones wrote:
Hello,

I have a garden retaining wall that seems to never dry out. The wall
is constructed from bricks with three stretcher courses and then one
header course repeated through its height. The wall is two courses
deep with what looks like a thin cavity inbetweeen. Two thirds of
the wall is below ground, the other third is above ground. At the
bottom of the wall there are some spaces in the mortar, presumably
weep holes.

Part of that statement isn't clear, weep holes are usually just
above ground level (but in high walls, there can be more than one
course of them) and not two thirds underground, Is all the wall
(except footings) exposed on your side, and the ground level behind
that rising two thirds up the wall?

What puzzles me is why is the whole wall damp, even the part that is
totally above ground? Any moisture coming from the earth that is
retained would I guess fall down the cavity and out the weep holes,
so I can't believe it is coming from there.

From what I read with the header and stretcher course description,
you have a solid 9" (one and half brick thick) wall and not a
cavity, and as it is a retaining wall, then you are correct, the
holes at the bottom are there to stop water pressure building up and
pushing the wall over. Believe me, it happens!

As for the damp, you don't say what the water table is, but there
may be a high one there, a small underground stream nearby or even a
leaking water/sewer pipe causing the wall to be damp.

Next to this garden wall is part of the house wall, this is dry, so
not damp from rain penetration. So maybe the whole garden wall has
rising damp, but why not the house wall?

The damp is probably not 'rising' but explained above. Now lets
assume that you are correct, then with the normal garden wall
construction, there are *NO* built in damp courses to prevent rising
damp nor damp proof membranes behind the wall to stop penetrating
damp due to higer ground levels.

The house will have all sorts of damp proof membranes built it.

And after reading this article I am doubtful that rising damp even
exists:

In the wall it could well do (contradiction of what I have already
said) but if the water table is low down and near the footings, the
wall will drag that moisture up naturally - but to no more than
around three feet in height from the water table.

http://www.architectsjournal.co.uk/n...ing-damp-is-a-....

This is really bugging me, I would really like to know the cause of
this damp!

Now you possibly know - but I'm sure other will have different ideas
that would also be possible.

Cash

Hello,

Thanks for your reply,

By two thirds underground I meant that two thirds of the wall retains
earth, the upper third retains nothing.

That's what I thought you meant - thanks.

There definitely is a small cavity between the two skins, the bricks
are old imperial size, 2 x the width of the brick does not match the
length.

Too small to be called a cavity Graham, the construction would be two
'stretcher courses' side-by-side for about four or five courses or so up,
and then a 'header course' at right angles to these as reinforcing method
(if the wall is 9" thick, then it will be classed as a 'solid' wall [1]).

The variations in the brick sizes may cause two stretchers side-by-side to
be slightly smaller than the length of a standard 9" brick and the old
brickie would have made adjustments for this as he was building the wall -
hence the "thin gap" between them.

[1] * *Cavity walls are usually a minimum of 11" thick and all stretcher
courses (generally) - I.E. stretcher course, 2" gap, stretcher course.

Cash

I see thanks.

I suppose my next question is, will the damp affect the life of the
wall and if so is there anything I can do about it?

Thanks,

Graham

Graham Jones wrote:
On Oct 19, 9:34 pm, "Cash"
wrote:
Graham Jones wrote:
On Oct 19, 8:52 pm, "Cash"
wrote:
Graham Jones wrote:
Hello,

I have a garden retaining wall that seems to never dry out. The
wall is constructed from bricks with three stretcher courses and
then one header course repeated through its height. The wall is
two courses deep with what looks like a thin cavity inbetweeen.
Two thirds of the wall is below ground, the other third is above
ground. At the bottom of the wall there are some spaces in the
mortar, presumably weep holes.

Part of that statement isn't clear, weep holes are usually just
above ground level (but in high walls, there can be more than one
course of them) and not two thirds underground, Is all the wall
(except footings) exposed on your side, and the ground level behind
that rising two thirds up the wall?

What puzzles me is why is the whole wall damp, even the part that
is totally above ground? Any moisture coming from the earth that
is retained would I guess fall down the cavity and out the weep
holes, so I can't believe it is coming from there.

From what I read with the header and stretcher course description,
you have a solid 9" (one and half brick thick) wall and not a
cavity, and as it is a retaining wall, then you are correct, the
holes at the bottom are there to stop water pressure building up
and pushing the wall over. Believe me, it happens!

As for the damp, you don't say what the water table is, but there
may be a high one there, a small underground stream nearby or even
a leaking water/sewer pipe causing the wall to be damp.

Next to this garden wall is part of the house wall, this is dry,
so not damp from rain penetration. So maybe the whole garden wall
has rising damp, but why not the house wall?

The damp is probably not 'rising' but explained above. Now lets
assume that you are correct, then with the normal garden wall
construction, there are *NO* built in damp courses to prevent
rising damp nor damp proof membranes behind the wall to stop
penetrating damp due to higer ground levels.

The house will have all sorts of damp proof membranes built it.

And after reading this article I am doubtful that rising damp even
exists:

In the wall it could well do (contradiction of what I have already
said) but if the water table is low down and near the footings, the
wall will drag that moisture up naturally - but to no more than
around three feet in height from the water table.

http://www.architectsjournal.co.uk/n...ing-damp-is-a-...

This is really bugging me, I would really like to know the cause
of this damp!

Now you possibly know - but I'm sure other will have different
ideas that would also be possible.

Cash

Hello,

Thanks for your reply,

By two thirds underground I meant that two thirds of the wall
retains earth, the upper third retains nothing.

That's what I thought you meant - thanks.

There definitely is a small cavity between the two skins, the bricks
are old imperial size, 2 x the width of the brick does not match the
length.

Too small to be called a cavity Graham, the construction would be two
'stretcher courses' side-by-side for about four or five courses or
so up, and then a 'header course' at right angles to these as
reinforcing method (if the wall is 9" thick, then it will be classed
as a 'solid' wall [1]).

The variations in the brick sizes may cause two stretchers
side-by-side to be slightly smaller than the length of a standard 9"
brick and the old brickie would have made adjustments for this as he
was building the wall - hence the "thin gap" between them.

[1] Cavity walls are usually a minimum of 11" thick and all stretcher
courses (generally) - I.E. stretcher course, 2" gap, stretcher
course.

Cash

I see thanks.

I suppose my next question is, will the damp affect the life of the
wall and if so is there anything I can do about it?

Thanks,

Graham

The answer to that could well be yes, more so when the weather is cold and
the temperature drops freezing, the water in the bricks then tends to freeze
and expand, causing the face of the bricks to 'blow' - especially if they
are 'concrete. bricks.

If the bricks are made of clay and 'FL' rated (or engineering bricks such as
the Staffordshire reds) then these frost resistant and more durable to the
cold.

As for doing anything about it! Generally no, but if you are feeling
energetic enough, you could dig the earth away from the back of the wall,
brush the wall clean and make good any defects - and then give the back of
the wall a few good coats of something like Synthaproof and then backfill.

On the exposed faces of both sides and top the wall, again check for, and
rectify any defects, and then give the wall a couple of good, heavy coats of
a clear silicone liquid (put the stuff on fairly heavily [using a spray is
best] and then let that soak in before giving it another coat.

This should stop most (if not all) of the damp and give the wall a longer
life - if the damp *is* rising, then for the above methods to be of use, you
will then have to consider inserting a chemical DPC to stop the rising damp
as well.

Now, down to the nitty-gritties - is it really worth the cost and hard toil
to do all that work, when that wall (even as it stands) may well have a life
of around 50 to 100 hundred years before it falls down (depending on type of
brick)?

In my case, if all looks ok now with its structural integrity - I would
personally leave well alone - as by time any real work is needed, I will be
long-gone and it will be somebody elses worry. ;-)

All the best.

Cash

On 19/10/2011 21:47, Graham Jones wrote:
On Oct 19, 9:34 pm,
wrote:
Graham Jones wrote:
On Oct 19, 8:52 pm,
wrote:
Graham Jones wrote:
Hello,

I have a garden retaining wall that seems to never dry out. The wall
is constructed from bricks with three stretcher courses and then one
header course repeated through its height. The wall is two courses
deep with what looks like a thin cavity inbetweeen. Two thirds of
the wall is below ground, the other third is above ground. At the
bottom of the wall there are some spaces in the mortar, presumably
weep holes.

Part of that statement isn't clear, weep holes are usually just
above ground level (but in high walls, there can be more than one
course of them) and not two thirds underground, Is all the wall
(except footings) exposed on your side, and the ground level behind
that rising two thirds up the wall?

What puzzles me is why is the whole wall damp, even the part that is
totally above ground? Any moisture coming from the earth that is
retained would I guess fall down the cavity and out the weep holes,
so I can't believe it is coming from there.

From what I read with the header and stretcher course description,
you have a solid 9" (one and half brick thick) wall and not a
cavity, and as it is a retaining wall, then you are correct, the
holes at the bottom are there to stop water pressure building up and
pushing the wall over. Believe me, it happens!

As for the damp, you don't say what the water table is, but there
may be a high one there, a small underground stream nearby or even a
leaking water/sewer pipe causing the wall to be damp.

Next to this garden wall is part of the house wall, this is dry, so
not damp from rain penetration. So maybe the whole garden wall has
rising damp, but why not the house wall?

The damp is probably not 'rising' but explained above. Now lets
assume that you are correct, then with the normal garden wall
construction, there are *NO* built in damp courses to prevent rising
damp nor damp proof membranes behind the wall to stop penetrating
damp due to higer ground levels.

The house will have all sorts of damp proof membranes built it.

And after reading this article I am doubtful that rising damp even
exists:

In the wall it could well do (contradiction of what I have already
said) but if the water table is low down and near the footings, the
wall will drag that moisture up naturally - but to no more than
around three feet in height from the water table.

http://www.architectsjournal.co.uk/n...ing-damp-is-a-...

This is really bugging me, I would really like to know the cause of
this damp!

Now you possibly know - but I'm sure other will have different ideas
that would also be possible.

Cash

Hello,

Thanks for your reply,

By two thirds underground I meant that two thirds of the wall retains
earth, the upper third retains nothing.

That's what I thought you meant - thanks.

There definitely is a small cavity between the two skins, the bricks
are old imperial size, 2 x the width of the brick does not match the
length.

Too small to be called a cavity Graham, the construction would be two
'stretcher courses' side-by-side for about four or five courses or so up,
and then a 'header course' at right angles to these as reinforcing method
(if the wall is 9" thick, then it will be classed as a 'solid' wall [1]).

The variations in the brick sizes may cause two stretchers side-by-side to
be slightly smaller than the length of a standard 9" brick and the old
brickie would have made adjustments for this as he was building the wall -
hence the "thin gap" between them.

[1] Cavity walls are usually a minimum of 11" thick and all stretcher
courses (generally) - I.E. stretcher course, 2" gap, stretcher course.

Cash

I see thanks.

I suppose my next question is, will the damp affect the life of the
wall and if so is there anything I can do about it?

Does it have lime mortar or cement?

On Oct 19, 11:20*pm, Maria wrote:
On 19/10/2011 21:47, Graham Jones wrote:







On Oct 19, 9:34 pm,
wrote:
Graham Jones wrote:
On Oct 19, 8:52 pm,
wrote:
Graham Jones wrote:
Hello,

I have a garden retaining wall that seems to never dry out. The wall
is constructed from bricks with three stretcher courses and then one
header course repeated through its height. The wall is two courses
deep with what looks like a thin cavity inbetweeen. Two thirds of
the wall is below ground, the other third is above ground. At the
bottom of the wall there are some spaces in the mortar, presumably
weep holes.

Part of that statement isn't clear, weep holes are usually just
above ground level (but in high walls, there can be more than one
course of them) and not two thirds underground, Is all the wall
(except footings) exposed on your side, and the ground level behind
that rising two thirds up the wall?

What puzzles me is why is the whole wall damp, even the part that is
totally above ground? Any moisture coming from the earth that is
retained would I guess fall down the cavity and out the weep holes,
so I can't believe it is coming from there.

*From what I read with the header and stretcher course description,
you have a solid 9" (one and half brick thick) wall and not a
cavity, and as it is a retaining wall, then you are correct, the
holes at the bottom are there to stop water pressure building up and
pushing the wall over. Believe me, it happens!

As for the damp, you don't say what the water table is, but there
may be a high one there, a small underground stream nearby or even a
leaking water/sewer pipe causing the wall to be damp.

Next to this garden wall is part of the house wall, this is dry, so
not damp from rain penetration. So maybe the whole garden wall has
rising damp, but why not the house wall?

The damp is probably not 'rising' but explained above. Now lets
assume that you are correct, then with the normal garden wall
construction, there are *NO* built in damp courses to prevent rising
damp nor damp proof membranes behind the wall to stop penetrating
damp due to higer ground levels.

The house will have all sorts of damp proof membranes built it.

And after reading this article I am doubtful that rising damp even
exists:

In the wall it could well do (contradiction of what I have already
said) but if the water table is low down and near the footings, the
wall will drag that moisture up naturally - but to no more than
around three feet in height from the water table.

http://www.architectsjournal.co.uk/n...ing-damp-is-a-...

This is really bugging me, I would really like to know the cause of
this damp!

Now you possibly know - but I'm sure other will have different ideas
that would also be possible.

Cash

Hello,

Thanks for your reply,

By two thirds underground I meant that two thirds of the wall retains
earth, the upper third retains nothing.

That's what I thought you meant - thanks.

There definitely is a small cavity between the two skins, the bricks
are old imperial size, 2 x the width of the brick does not match the
length.

Too small to be called a cavity Graham, the construction would be two
'stretcher courses' side-by-side for about four or five courses or so up,
and then a 'header course' at right angles to these as reinforcing method
(if the wall is 9" thick, then it will be classed as a 'solid' wall [1]).

The variations in the brick sizes may cause two stretchers side-by-side to
be slightly smaller than the length of a standard 9" brick and the old
brickie would have made adjustments for this as he was building the wall -
hence the "thin gap" between them.

[1] * *Cavity walls are usually a minimum of 11" thick and all stretcher
courses (generally) - I.E. stretcher course, 2" gap, stretcher course.

Cash

I see thanks.

I suppose my next question is, will the damp affect the life of the
wall and if so is there anything I can do about it?

Does it have lime mortar or cement?

Cement

On 20/10/2011 08:01, Graham Jones wrote:
On Oct 19, 11:20 pm, wrote:
On 19/10/2011 21:47, Graham Jones wrote:







On Oct 19, 9:34 pm,
wrote:
Graham Jones wrote:
On Oct 19, 8:52 pm,
wrote:
Graham Jones wrote:
Hello,

I have a garden retaining wall that seems to never dry out. The wall
is constructed from bricks with three stretcher courses and then one
header course repeated through its height. The wall is two courses
deep with what looks like a thin cavity inbetweeen. Two thirds of
the wall is below ground, the other third is above ground. At the
bottom of the wall there are some spaces in the mortar, presumably
weep holes.

Part of that statement isn't clear, weep holes are usually just
above ground level (but in high walls, there can be more than one
course of them) and not two thirds underground, Is all the wall
(except footings) exposed on your side, and the ground level behind
that rising two thirds up the wall?

What puzzles me is why is the whole wall damp, even the part that is
totally above ground? Any moisture coming from the earth that is
retained would I guess fall down the cavity and out the weep holes,
so I can't believe it is coming from there.

From what I read with the header and stretcher course description,
you have a solid 9" (one and half brick thick) wall and not a
cavity, and as it is a retaining wall, then you are correct, the
holes at the bottom are there to stop water pressure building up and
pushing the wall over. Believe me, it happens!

As for the damp, you don't say what the water table is, but there
may be a high one there, a small underground stream nearby or even a
leaking water/sewer pipe causing the wall to be damp.

Next to this garden wall is part of the house wall, this is dry, so
not damp from rain penetration. So maybe the whole garden wall has
rising damp, but why not the house wall?

The damp is probably not 'rising' but explained above. Now lets
assume that you are correct, then with the normal garden wall
construction, there are *NO* built in damp courses to prevent rising
damp nor damp proof membranes behind the wall to stop penetrating
damp due to higer ground levels.

The house will have all sorts of damp proof membranes built it.

And after reading this article I am doubtful that rising damp even
exists:

In the wall it could well do (contradiction of what I have already
said) but if the water table is low down and near the footings, the
wall will drag that moisture up naturally - but to no more than
around three feet in height from the water table.

http://www.architectsjournal.co.uk/n...ing-damp-is-a-...

This is really bugging me, I would really like to know the cause of
this damp!

Now you possibly know - but I'm sure other will have different ideas
that would also be possible.

Cash

Hello,

Thanks for your reply,

By two thirds underground I meant that two thirds of the wall retains
earth, the upper third retains nothing.

That's what I thought you meant - thanks.

There definitely is a small cavity between the two skins, the bricks
are old imperial size, 2 x the width of the brick does not match the
length.

Too small to be called a cavity Graham, the construction would be two
'stretcher courses' side-by-side for about four or five courses or so up,
and then a 'header course' at right angles to these as reinforcing method
(if the wall is 9" thick, then it will be classed as a 'solid' wall [1]).

The variations in the brick sizes may cause two stretchers side-by-side to
be slightly smaller than the length of a standard 9" brick and the old
brickie would have made adjustments for this as he was building the wall -
hence the "thin gap" between them.

[1] Cavity walls are usually a minimum of 11" thick and all stretcher
courses (generally) - I.E. stretcher course, 2" gap, stretcher course.

Cash

I see thanks.

I suppose my next question is, will the damp affect the life of the
wall and if so is there anything I can do about it?

Does it have lime mortar or cement?

Cement

If the bricks are perpetually wet, they will probably spall over time
(erode away behind the cement mortar) because the cement is stronger
than the brick. Is it just pointed with cement mortar over old lime
mortar, or is it cement mortar all through?

Maria wrote:
On 20/10/2011 08:01, Graham Jones wrote:
On Oct 19, 11:20 pm, wrote:
On 19/10/2011 21:47, Graham Jones wrote:







On Oct 19, 9:34 pm,
wrote:
Graham Jones wrote:
On Oct 19, 8:52 pm,
wrote:
Graham Jones wrote:
Hello,

I have a garden retaining wall that seems to never dry out.
The wall is constructed from bricks with three stretcher
courses and then one header course repeated through its
height. The wall is two courses deep with what looks like a
thin cavity inbetweeen. Two thirds of the wall is below
ground, the other third is above ground. At the bottom of the
wall there are some spaces in the mortar, presumably weep
holes.

Part of that statement isn't clear, weep holes are usually just
above ground level (but in high walls, there can be more than
one course of them) and not two thirds underground, Is all the
wall (except footings) exposed on your side, and the ground
level behind that rising two thirds up the wall?

What puzzles me is why is the whole wall damp, even the part
that is totally above ground? Any moisture coming from the
earth that is retained would I guess fall down the cavity and
out the weep holes, so I can't believe it is coming from there.

From what I read with the header and stretcher course
description, you have a solid 9" (one and half brick thick)
wall and not a cavity, and as it is a retaining wall, then you
are correct, the holes at the bottom are there to stop water
pressure building up and pushing the wall over. Believe me, it
happens!

As for the damp, you don't say what the water table is, but
there may be a high one there, a small underground stream
nearby or even a leaking water/sewer pipe causing the wall to
be damp.

Next to this garden wall is part of the house wall, this is
dry, so not damp from rain penetration. So maybe the whole
garden wall has rising damp, but why not the house wall?

The damp is probably not 'rising' but explained above. Now lets
assume that you are correct, then with the normal garden wall
construction, there are *NO* built in damp courses to prevent
rising damp nor damp proof membranes behind the wall to stop
penetrating damp due to higer ground levels.

The house will have all sorts of damp proof membranes built it.

And after reading this article I am doubtful that rising damp
even exists:

In the wall it could well do (contradiction of what I have
already said) but if the water table is low down and near the
footings, the wall will drag that moisture up naturally - but
to no more than around three feet in height from the water
table.

http://www.architectsjournal.co.uk/n...ing-damp-is-a-...

This is really bugging me, I would really like to know the
cause of this damp!

Now you possibly know - but I'm sure other will have different
ideas that would also be possible.

Cash

Hello,

Thanks for your reply,

By two thirds underground I meant that two thirds of the wall
retains earth, the upper third retains nothing.

That's what I thought you meant - thanks.

There definitely is a small cavity between the two skins, the
bricks are old imperial size, 2 x the width of the brick does
not match the length.

Too small to be called a cavity Graham, the construction would be
two 'stretcher courses' side-by-side for about four or five
courses or so up, and then a 'header course' at right angles to
these as reinforcing method (if the wall is 9" thick, then it
will be classed as a 'solid' wall [1]).

The variations in the brick sizes may cause two stretchers
side-by-side to be slightly smaller than the length of a standard
9" brick and the old brickie would have made adjustments for this
as he was building the wall - hence the "thin gap" between them.

[1] Cavity walls are usually a minimum of 11" thick and all
stretcher courses (generally) - I.E. stretcher course, 2" gap,
stretcher course.

Cash

I see thanks.

I suppose my next question is, will the damp affect the life of the
wall and if so is there anything I can do about it?

Does it have lime mortar or cement?

Cement

If the bricks are perpetually wet, they will probably spall over time
(erode away behind the cement mortar) because the cement is stronger
than the brick. Is it just pointed with cement mortar over old lime
mortar, or is it cement mortar all through?

Maria,

Just out of interest, where does the cement jointing come into the equation
with the actual spalling of the brick - which in most bricks (clay or
concrete) is caused simply by weather [frost] damage and leaving the joints
relatively undamaged?

If the joints are affected to any major degree by a poor mix, incorrect
material or weather damage, then that usually results in vertical or
horizontal cracking or lifting which, combined with water pressure or ground
movement can cause the wall to 'lean' or collapse.

The only time bricks will spall "behind" the morter is if the wall has been
rendered.

If you live anywhere near Stoke on Trent, [1] have a look a the canal system
that winds its way through parts of the place, the walls of some of the
buildings actually form the retaining wall for the canal and have no other
form of water proofing than the bricks themselves. The bricks by the way
are either Staffordshire Reds or Blues and are engineering quality - and
seem to last forever!

[1] I once has a 6 month contract up there at Hanley, working on some
properties.


Cash

On 20/10/2011 22:34, Cash wrote:
Maria wrote:
On 20/10/2011 08:01, Graham Jones wrote:
On Oct 19, 11:20 pm, wrote:
On 19/10/2011 21:47, Graham Jones wrote:







On Oct 19, 9:34 pm,
wrote:
Graham Jones wrote:
On Oct 19, 8:52 pm,
wrote:
Graham Jones wrote:
Hello,

I have a garden retaining wall that seems to never dry out.
The wall is constructed from bricks with three stretcher
courses and then one header course repeated through its
height. The wall is two courses deep with what looks like a
thin cavity inbetweeen. Two thirds of the wall is below
ground, the other third is above ground. At the bottom of the
wall there are some spaces in the mortar, presumably weep
holes.

Part of that statement isn't clear, weep holes are usually just
above ground level (but in high walls, there can be more than
one course of them) and not two thirds underground, Is all the
wall (except footings) exposed on your side, and the ground
level behind that rising two thirds up the wall?

What puzzles me is why is the whole wall damp, even the part
that is totally above ground? Any moisture coming from the
earth that is retained would I guess fall down the cavity and
out the weep holes, so I can't believe it is coming from there.

From what I read with the header and stretcher course
description, you have a solid 9" (one and half brick thick)
wall and not a cavity, and as it is a retaining wall, then you
are correct, the holes at the bottom are there to stop water
pressure building up and pushing the wall over. Believe me, it
happens!

As for the damp, you don't say what the water table is, but
there may be a high one there, a small underground stream
nearby or even a leaking water/sewer pipe causing the wall to
be damp.

Next to this garden wall is part of the house wall, this is
dry, so not damp from rain penetration. So maybe the whole
garden wall has rising damp, but why not the house wall?

The damp is probably not 'rising' but explained above. Now lets
assume that you are correct, then with the normal garden wall
construction, there are *NO* built in damp courses to prevent
rising damp nor damp proof membranes behind the wall to stop
penetrating damp due to higer ground levels.

The house will have all sorts of damp proof membranes built it.

And after reading this article I am doubtful that rising damp
even exists:

In the wall it could well do (contradiction of what I have
already said) but if the water table is low down and near the
footings, the wall will drag that moisture up naturally - but
to no more than around three feet in height from the water
table.

http://www.architectsjournal.co.uk/n...ing-damp-is-a-...

This is really bugging me, I would really like to know the
cause of this damp!

Now you possibly know - but I'm sure other will have different
ideas that would also be possible.

Cash

Hello,

Thanks for your reply,

By two thirds underground I meant that two thirds of the wall
retains earth, the upper third retains nothing.

That's what I thought you meant - thanks.

There definitely is a small cavity between the two skins, the
bricks are old imperial size, 2 x the width of the brick does
not match the length.

Too small to be called a cavity Graham, the construction would be
two 'stretcher courses' side-by-side for about four or five
courses or so up, and then a 'header course' at right angles to
these as reinforcing method (if the wall is 9" thick, then it
will be classed as a 'solid' wall [1]).

The variations in the brick sizes may cause two stretchers
side-by-side to be slightly smaller than the length of a standard
9" brick and the old brickie would have made adjustments for this
as he was building the wall - hence the "thin gap" between them.

[1] Cavity walls are usually a minimum of 11" thick and all
stretcher courses (generally) - I.E. stretcher course, 2" gap,
stretcher course.

Cash

I see thanks.

I suppose my next question is, will the damp affect the life of the
wall and if so is there anything I can do about it?

Does it have lime mortar or cement?

Cement

If the bricks are perpetually wet, they will probably spall over time
(erode away behind the cement mortar) because the cement is stronger
than the brick. Is it just pointed with cement mortar over old lime
mortar, or is it cement mortar all through?

Maria,

Just out of interest, where does the cement jointing come into the equation
with the actual spalling of the brick - which in most bricks (clay or
concrete) is caused simply by weather [frost] damage and leaving the joints
relatively undamaged?

Cement mortar does not allow the passage of water as lime mortars do,
trapping water in the brick. The brick then degrades rather than the
mortar, the latter which is what is meant to happen.


If the joints are affected to any major degree by a poor mix, incorrect
material or weather damage, then that usually results in vertical or
horizontal cracking or lifting which, combined with water pressure or ground
movement can cause the wall to 'lean' or collapse.

That too!


The only time bricks will spall "behind" the morter is if the wall has been
rendered.

Have to disagree on that one. If the building brick/stone is softer than
the mortar, then the mortar is not the weakest part. Water is then
forced out through the surface of the brick.

http://www.greenbuildingforum.co.uk/...achmentID=1267

I really like this pic (which once had some stone in it!)

http://www.scotlime.org/images/cement.jpg

http://www.homebuilding.co.uk/files/...ladding_02.jpg
http://www.regencyconstruction.co.uk/Re-pointing.html



If you live anywhere near Stoke on Trent, [1] have a look a the canal system
that winds its way through parts of the place, the walls of some of the
buildings actually form the retaining wall for the canal and have no other
form of water proofing than the bricks themselves. The bricks by the way
are either Staffordshire Reds or Blues and are engineering quality - and
seem to last forever!

[1] I once has a 6 month contract up there at Hanley, working on some
properties.

Are they constructed with Ashlar joints? Engineering bricks are
amazingly strong, and would take a lot more to destroy them. I am
currently repointing with some hydraulic lime mortar, which can be used
under water!

I would take a guess and say that Graham's wall is older brick (on which
the facings may have been damaged), which has been repointed or rebuilt
using cement mortar. Assuming he can find no point of ingress.
But I'm better with photos.

On Oct 19, 10:10 pm, "Cash"
wrote:
Graham Jones wrote:
On Oct 19, 9:34 pm, "Cash"
wrote:
Graham Jones wrote:
On Oct 19, 8:52 pm, "Cash"
wrote:
Graham Jones wrote:
Hello,

I have a garden retaining wall that seems to never dry out. The
wall is constructed from bricks with three stretcher courses and
then one header course repeated through its height. The wall is
two courses deep with what looks like a thin cavity inbetweeen.
Two thirds of the wall is below ground, the other third is above
ground. At the bottom of the wall there are some spaces in the
mortar, presumably weep holes.

Part of that statement isn't clear, weep holes are usually just
above ground level (but in high walls, there can be more than one
course of them) and not two thirds underground, Is all the wall
(except footings) exposed on your side, and the ground level behind
that rising two thirds up the wall?

What puzzles me is why is the whole wall damp, even the part that
is totally above ground? Any moisture coming from the earth that
is retained would I guess fall down the cavity and out the weep
holes, so I can't believe it is coming from there.

From what I read with the header and stretcher course description,
you have a solid 9" (one and half brick thick) wall and not a
cavity, and as it is a retaining wall, then you are correct, the
holes at the bottom are there to stop water pressure building up
and pushing the wall over. Believe me, it happens!

As for the damp, you don't say what the water table is, but there
may be a high one there, a small underground stream nearby or even
a leaking water/sewer pipe causing the wall to be damp.

Next to this garden wall is part of the house wall, this is dry,
so not damp from rain penetration. So maybe the whole garden wall
has rising damp, but why not the house wall?

The damp is probably not 'rising' but explained above. Now lets
assume that you are correct, then with the normal garden wall
construction, there are *NO* built in damp courses to prevent
rising damp nor damp proof membranes behind the wall to stop
penetrating damp due to higer ground levels.

The house will have all sorts of damp proof membranes built it.

And after reading this article I am doubtful that rising damp even
exists:

In the wall it could well do (contradiction of what I have already
said) but if the water table is low down and near the footings, the
wall will drag that moisture up naturally - but to no more than
around three feet in height from the water table.

http://www.architectsjournal.co.uk/n...ing-damp-is-a-...

This is really bugging me, I would really like to know the cause
of this damp!

Now you possibly know - but I'm sure other will have different
ideas that would also be possible.

Cash

Hello,

Thanks for your reply,

By two thirds underground I meant that two thirds of the wall
retains earth, the upper third retains nothing.

That's what I thought you meant - thanks.

There definitely is a small cavity between the two skins, the bricks
are old imperial size, 2 x the width of the brick does not match the
length.

Too small to be called a cavity Graham, the construction would be two
'stretcher courses' side-by-side for about four or five courses or
so up, and then a 'header course' at right angles to these as
reinforcing method (if the wall is 9" thick, then it will be classed
as a 'solid' wall [1]).

The variations in the brick sizes may cause two stretchers
side-by-side to be slightly smaller than the length of a standard 9"
brick and the old brickie would have made adjustments for this as he
was building the wall - hence the "thin gap" between them.

[1] Cavity walls are usually a minimum of 11" thick and all stretcher
courses (generally) - I.E. stretcher course, 2" gap, stretcher
course.

Cash

I see thanks.

I suppose my next question is, will the damp affect the life of the
wall and if so is there anything I can do about it?

Thanks,

Graham

The answer to that could well be yes, more so when the weather is cold and
the temperature drops freezing, the water in the bricks then tends to freeze
and expand, causing the face of the bricks to 'blow' - especially if they
are 'concrete. bricks.

If the bricks are made of clay and 'FL' rated (or engineering bricks such as
the Staffordshire reds) then these frost resistant and more durable to the
cold.

As for doing anything about it! Generally no, but if you are feeling
energetic enough, you could dig the earth away from the back of the wall,
brush the wall clean and make good any defects - and then give the back of
the wall a few good coats of something like Synthaproof and then backfill.

nah, dig it out then replace the earth behind with free draining stone
(against a membrane on the retained earth side) so that moisture falls
down and comes out at the base through weep holes/pipes in the wall at
ground level rather than through the structure?

Jim K

Jim K wrote:
On Oct 19, 10:10 pm, "Cash"
wrote:
Graham Jones wrote:
On Oct 19, 9:34 pm, "Cash"
wrote:
Graham Jones wrote:
On Oct 19, 8:52 pm, "Cash"
wrote:
Graham Jones wrote:
Hello,

I have a garden retaining wall that seems to never dry out. The
wall is constructed from bricks with three stretcher courses and
then one header course repeated through its height. The wall is
two courses deep with what looks like a thin cavity inbetweeen.
Two thirds of the wall is below ground, the other third is above
ground. At the bottom of the wall there are some spaces in the
mortar, presumably weep holes.

Part of that statement isn't clear, weep holes are usually just
above ground level (but in high walls, there can be more than one
course of them) and not two thirds underground, Is all the wall
(except footings) exposed on your side, and the ground level
behind that rising two thirds up the wall?

What puzzles me is why is the whole wall damp, even the part
that is totally above ground? Any moisture coming from the
earth that is retained would I guess fall down the cavity and
out the weep holes, so I can't believe it is coming from there.

From what I read with the header and stretcher course
description, you have a solid 9" (one and half brick thick) wall
and not a cavity, and as it is a retaining wall, then you are
correct, the holes at the bottom are there to stop water
pressure building up and pushing the wall over. Believe me, it
happens!

As for the damp, you don't say what the water table is, but there
may be a high one there, a small underground stream nearby or
even a leaking water/sewer pipe causing the wall to be damp.

Next to this garden wall is part of the house wall, this is dry,
so not damp from rain penetration. So maybe the whole garden
wall has rising damp, but why not the house wall?

The damp is probably not 'rising' but explained above. Now lets
assume that you are correct, then with the normal garden wall
construction, there are *NO* built in damp courses to prevent
rising damp nor damp proof membranes behind the wall to stop
penetrating damp due to higer ground levels.

The house will have all sorts of damp proof membranes built it.

And after reading this article I am doubtful that rising damp
even exists:

In the wall it could well do (contradiction of what I have
already said) but if the water table is low down and near the
footings, the wall will drag that moisture up naturally - but to
no more than around three feet in height from the water table.

http://www.architectsjournal.co.uk/n...ing-damp-is-a-...

This is really bugging me, I would really like to know the cause
of this damp!

Now you possibly know - but I'm sure other will have different
ideas that would also be possible.

Cash

Hello,

Thanks for your reply,

By two thirds underground I meant that two thirds of the wall
retains earth, the upper third retains nothing.

That's what I thought you meant - thanks.

There definitely is a small cavity between the two skins, the
bricks are old imperial size, 2 x the width of the brick does not
match the length.

Too small to be called a cavity Graham, the construction would be
two 'stretcher courses' side-by-side for about four or five
courses or so up, and then a 'header course' at right angles to
these as reinforcing method (if the wall is 9" thick, then it will
be classed as a 'solid' wall [1]).

The variations in the brick sizes may cause two stretchers
side-by-side to be slightly smaller than the length of a standard
9" brick and the old brickie would have made adjustments for this
as he was building the wall - hence the "thin gap" between them.

[1] Cavity walls are usually a minimum of 11" thick and all
stretcher courses (generally) - I.E. stretcher course, 2" gap,
stretcher course.

Cash

I see thanks.

I suppose my next question is, will the damp affect the life of the
wall and if so is there anything I can do about it?

Thanks,

Graham

The answer to that could well be yes, more so when the weather is
cold and the temperature drops freezing, the water in the bricks
then tends to freeze and expand, causing the face of the bricks to
'blow' - especially if they are 'concrete. bricks.

If the bricks are made of clay and 'FL' rated (or engineering bricks
such as the Staffordshire reds) then these frost resistant and more
durable to the cold.

As for doing anything about it! Generally no, but if you are feeling
energetic enough, you could dig the earth away from the back of the
wall, brush the wall clean and make good any defects - and then give
the back of the wall a few good coats of something like Synthaproof
and then backfill.

nah, dig it out then replace the earth behind with free draining stone
(against a membrane on the retained earth side) so that moisture falls
down and comes out at the base through weep holes/pipes in the wall at
ground level rather than through the structure?

Jim K

Same effect Jim, but still bloody hard work just to keep a retaining wall
dry.

As a matter of interest, if I had a problem like that, I would be trying to
find the cause of the damp and solve that - and a sample of the water sent
away for analysis would help to determine if it was a sewer, mains water or
an underground spring problem (the local water board company may even help
with that).

Cash

Maria wrote:
On 20/10/2011 22:34, Cash wrote:
Maria wrote:
On 20/10/2011 08:01, Graham Jones wrote:
On Oct 19, 11:20 pm, wrote:
On 19/10/2011 21:47, Graham Jones wrote:







On Oct 19, 9:34 pm,
wrote:
Graham Jones wrote:
On Oct 19, 8:52 pm,
wrote:
Graham Jones wrote:
Hello,

I have a garden retaining wall that seems to never dry out.
The wall is constructed from bricks with three stretcher
courses and then one header course repeated through its
height. The wall is two courses deep with what looks like a
thin cavity inbetweeen. Two thirds of the wall is below
ground, the other third is above ground. At the bottom of the
wall there are some spaces in the mortar, presumably weep
holes.

Part of that statement isn't clear, weep holes are usually
just above ground level (but in high walls, there can be more
than one course of them) and not two thirds underground, Is
all the wall (except footings) exposed on your side, and the
ground level behind that rising two thirds up the wall?

What puzzles me is why is the whole wall damp, even the part
that is totally above ground? Any moisture coming from the
earth that is retained would I guess fall down the cavity and
out the weep holes, so I can't believe it is coming from
there.

From what I read with the header and stretcher course
description, you have a solid 9" (one and half brick thick)
wall and not a cavity, and as it is a retaining wall, then you
are correct, the holes at the bottom are there to stop water
pressure building up and pushing the wall over. Believe me, it
happens!

As for the damp, you don't say what the water table is, but
there may be a high one there, a small underground stream
nearby or even a leaking water/sewer pipe causing the wall to
be damp.

Next to this garden wall is part of the house wall, this is
dry, so not damp from rain penetration. So maybe the whole
garden wall has rising damp, but why not the house wall?

The damp is probably not 'rising' but explained above. Now
lets assume that you are correct, then with the normal garden
wall construction, there are *NO* built in damp courses to
prevent rising damp nor damp proof membranes behind the wall
to stop penetrating damp due to higer ground levels.

The house will have all sorts of damp proof membranes built
it.

And after reading this article I am doubtful that rising damp
even exists:

In the wall it could well do (contradiction of what I have
already said) but if the water table is low down and near the
footings, the wall will drag that moisture up naturally - but
to no more than around three feet in height from the water
table.

http://www.architectsjournal.co.uk/n...ing-damp-is-a-...

This is really bugging me, I would really like to know the
cause of this damp!

Now you possibly know - but I'm sure other will have different
ideas that would also be possible.

Cash

Hello,

Thanks for your reply,

By two thirds underground I meant that two thirds of the wall
retains earth, the upper third retains nothing.

That's what I thought you meant - thanks.

There definitely is a small cavity between the two skins, the
bricks are old imperial size, 2 x the width of the brick does
not match the length.

Too small to be called a cavity Graham, the construction would
be two 'stretcher courses' side-by-side for about four or five
courses or so up, and then a 'header course' at right angles to
these as reinforcing method (if the wall is 9" thick, then it
will be classed as a 'solid' wall [1]).

The variations in the brick sizes may cause two stretchers
side-by-side to be slightly smaller than the length of a
standard 9" brick and the old brickie would have made
adjustments for this as he was building the wall - hence the
"thin gap" between them.

[1] Cavity walls are usually a minimum of 11" thick and all
stretcher courses (generally) - I.E. stretcher course, 2" gap,
stretcher course.

Cash

I see thanks.

I suppose my next question is, will the damp affect the life of
the wall and if so is there anything I can do about it?

Does it have lime mortar or cement?

Cement

If the bricks are perpetually wet, they will probably spall over
time (erode away behind the cement mortar) because the cement is
stronger than the brick. Is it just pointed with cement mortar over
old lime mortar, or is it cement mortar all through?

Maria,

Just out of interest, where does the cement jointing come into the
equation with the actual spalling of the brick - which in most
bricks (clay or concrete) is caused simply by weather [frost] damage
and leaving the joints relatively undamaged?

Cement mortar does not allow the passage of water as lime mortars do,
trapping water in the brick. The brick then degrades rather than the
mortar, the latter which is what is meant to happen.

But the problem is that the wall consists of probably around 95% of
brickwork and only around 5% of cement jointing - you can ignore the cement
jointing in any form here, adding more weepholes to the wall at higher
levels by drilling with a 3" core drill will have more effect.

Also, I would be very wary of using a weaker lime mortar in a retaining wall
for very obvious reasons.


If the joints are affected to any major degree by a poor mix,
incorrect material or weather damage, then that usually results in
vertical or horizontal cracking or lifting which, combined with
water pressure or ground movement can cause the wall to 'lean' or
collapse.

That too!


The only time bricks will spall "behind" the morter is if the wall
has been rendered.

Have to disagree on that one. If the building brick/stone is softer
than the mortar, then the mortar is not the weakest part. Water is
then forced out through the surface of the brick.

Water is not generally 'forced' through the brick, most bricks are naturally
porus and absorb the stuff - and in the low temperatures of winter, the
water freezes and expands and simply 'crack' the brick during that process.

http://www.greenbuildingforum.co.uk/...achmentID=1267

That is a very soft brick by the look of it and very susceptible to water
absorption and ultimately frost damage - and the laying a point aren't that
good.

I really like this pic (which once had some stone in it!)

http://www.scotlime.org/images/cement.jpg

Again it appears to be a very soft and old brick.

http://www.homebuilding.co.uk/files/...ladding_02.jpg
http://www.regencyconstruction.co.uk/Re-pointing.html


If you live anywhere near Stoke on Trent, [1] have a look a the
canal system that winds its way through parts of the place, the
walls of some of the buildings actually form the retaining wall for
the canal and have no other form of water proofing than the bricks
themselves. The bricks by the way are either Staffordshire Reds or
Blues and are engineering quality - and seem to last forever!

[1] I once has a 6 month contract up there at Hanley, working on
some properties.

Are they constructed with Ashlar joints? Engineering bricks are
amazingly strong, and would take a lot more to destroy them. I am
currently repointing with some hydraulic lime mortar, which can be
used under water!

Didn't get that close to them, I was simply driving past the buildings.

I would take a guess and say that Graham's wall is older brick (on
which the facings may have been damaged), which has been repointed or
rebuilt using cement mortar. Assuming he can find no point of ingress.
But I'm better with photos.

From the lack of information (and past experience) I would suggest that his
wall is a lot more recent and is not suffering from damage as yet, and has
neither been repointed or rebuilt - he simply asked what damage would be
caused by the water, which is simply being dragged through the wall by the
capillary action of a porus common brick [1] (as he hasn't stated if water
was coming through the existing weep holes.

As for point of ingress, that's through the ground that rises two thirds of
the way up the rear of the wall.

[1] And unlikely to be frost resistant.

Cash