We've got a brick garage (single brick walls). There are two damp
problems

1. Retaining wall for next door's garden. The close is built on a
hill and next door's garden is about 500mm higher than the floor of
the garage. When it rains very hard there's a gentle seep through the
wall that pools on the floor - maximum 50mm of water, so not a lot.

I really don't want to mess around waterproofing the outside wall as
it's not a big deal. Normally it wouldn't matter as we don't use the
garage for much. However I was hoping to fit our old kitchen units
into the garage today when I found out about this and there is enough
water to blow them.

The good news is that this is on the wall that is to form the side of
the run and is well below the height of the worktop, so it's only
going to affect that one side.

I'm currently thinking of a bodge using a piece of perspex to protect
the side of the unit, perhaps combined with some plastic sheeting
under it. Or could an internal sealer paint be expected to hold up to
this low-volume seeping? Even if it could, is it a good idea to
effectively seal that damp into the brick?


2. Driving rain seeps through wall. A bigger, but less urgent, issue
is that when it rains hard the prevailing wind drives it through the
other side wall. There are numerous seeps through, although this
tends to just lead to really wet walls rather than pudddles on the
floor.

What's best practice here? I'm happy to paint the inside and to treat
the outside (presumably after everything has had a chance to dry),
although I'd like the outside coat to keep the general look of
unpainted brick. For example I've just used garage floor sealer and
I'd be happy with that level of shade change to the brick but I
wouldn't like to paint the exterior walls a colour.

Thanks.

wrote in message
...
We've got a brick garage (single brick walls). There are two damp
problems

1. Retaining wall for next door's garden. The close is built on a
hill and next door's garden is about 500mm higher than the floor of
the garage. When it rains very hard there's a gentle seep through the
wall that pools on the floor - maximum 50mm of water, so not a lot.

I really don't want to mess around waterproofing the outside wall as
it's not a big deal. Normally it wouldn't matter as we don't use the
garage for much. However I was hoping to fit our old kitchen units
into the garage today when I found out about this and there is enough
water to blow them.

The good news is that this is on the wall that is to form the side of
the run and is well below the height of the worktop, so it's only
going to affect that one side.

I'm currently thinking of a bodge using a piece of perspex to protect
the side of the unit, perhaps combined with some plastic sheeting
under it. Or could an internal sealer paint be expected to hold up to
this low-volume seeping? Even if it could, is it a good idea to
effectively seal that damp into the brick?

Provide a shallow gulley by cutting a small channel into the floor to an
outside point that can take the water.



2. Driving rain seeps through wall. A bigger, but less urgent, issue
is that when it rains hard the prevailing wind drives it through the
other side wall. There are numerous seeps through, although this
tends to just lead to really wet walls rather than pudddles on the
floor.

What's best practice here? I'm happy to paint the inside and to treat
the outside (presumably after everything has had a chance to dry),
although I'd like the outside coat to keep the general look of
unpainted brick. For example I've just used garage floor sealer and
I'd be happy with that level of shade change to the brick but I
wouldn't like to paint the exterior walls a colour.


Wait for some dry weather and waterproof the outside of the walls with clear
silicon waterproofing liquid.

On 2 Dec, 15:12, "
wrote:
We've got a brick garage (single brick walls). There are two damp
problems

1. Retaining wall for next door's garden. The close is built on a
hill and next door's garden is about 500mm higher than the floor of
the garage. When it rains very hard there's a gentle seep through the
wall that pools on the floor - maximum 50mm of water, so not a lot.

I really don't want to mess around waterproofing the outside wall as
it's not a big deal. Normally it wouldn't matter as we don't use the
garage for much. However I was hoping to fit our old kitchen units
into the garage today when I found out about this and there is enough
water to blow them.

The good news is that this is on the wall that is to form the side of
the run and is well below the height of the worktop, so it's only
going to affect that one side.

I'm currently thinking of a bodge using a piece of perspex to protect
the side of the unit, perhaps combined with some plastic sheeting
under it. Or could an internal sealer paint be expected to hold up to
this low-volume seeping? Even if it could, is it a good idea to
effectively seal that damp into the brick?

2. Driving rain seeps through wall. A bigger, but less urgent, issue
is that when it rains hard the prevailing wind drives it through the
other side wall. There are numerous seeps through, although this
tends to just lead to really wet walls rather than pudddles on the
floor.

What's best practice here? I'm happy to paint the inside and to treat
the outside (presumably after everything has had a chance to dry),
although I'd like the outside coat to keep the general look of
unpainted brick. For example I've just used garage floor sealer and
I'd be happy with that level of shade change to the brick but I
wouldn't like to paint the exterior walls a colour.

Thanks.

Dear 86

The best practice is to render externally.
However, you make it clear that you do not wish to do that so for the
second problem I would use a stearate-based external brick water
repellant and am completely against any form of silicone. Ideally, you
want a layer that is water repellant but vapour porous not a water
proof layer.
For the first problem I would personally use Sika No 1 and render the
part of the wall and floor causing the problem if I could not gain
access to the outside but best solution is to ask your next door
neighbour for cooperation (technically he is allowing a nuisance in
law and you could force him but clearly that would be ott) and attack
the problem at source. Consider a lead capping on the abutting wall,
similar water repellant treatement and / or lowering of ground (if
that is a problem) insertion of dpm between his abutting wall and
yours etc etc
Chris

Thanks guys. I went to the local Focus to see what they had and
spotted some Thompson's Water Seal which takes care of the penetrating
rain issue. They do two kinds, the normal Water Seal (which seems to
be a stearate-based one) and the Water Seal Ultra which is silicone.
The silicone one does seem to last longer so I was wondering why Chris
dislikes them so much for external garage walls. As long as the
inside can breathe (and it's pretty draughty in there ), isn't that
sufficient?

Regarding the garage/garden retaining wall issue, the two shed
solutions seem to be:
(a) Unibond Waterproof PVA mixed with cement and brushed on
(b) That silicone Water Seal Ultra (although I see on the can it says
"Don't use on garden rataining walls")

Has anyone used that waterproof PVA on a cellar or similar?

Does anyone know the reason why the silicone water seal says not to
use on retaining walls - what would happen if I sealed the entire damp
area? Is it something to do with needing to use a seal/render/etc.
that is breathable to allow the bricks/mortar to dry? What would be
the risk of sealing a 600*600mm section of the wall, bearing in mind
that I'm happy with the small amount of water entering the garage, I
just don't want it to enter where it can blow the cupboards.

I had a look at Sika but it looks too thick and bulky considering I
only need to treat 600*600mm of a 5000*2400mm wall. Thanks for the
recommendation though.

wrote:
Thanks guys. I went to the local Focus to see what they had and
spotted some Thompson's Water Seal which takes care of the penetrating
rain issue.

You might be being a little over optimistic there. If the brickwork is
porous you'll get through gallons of the stuff and IME it might achieve
nothing.


They do two kinds, the normal Water Seal (which seems to
be a stearate-based one) and the Water Seal Ultra which is silicone.
The silicone one does seem to last longer so I was wondering why Chris
dislikes them so much for external garage walls. As long as the
inside can breathe (and it's pretty draughty in there ), isn't that
sufficient?

Regarding the garage/garden retaining wall issue, the two shed
solutions seem to be:
(a) Unibond Waterproof PVA mixed with cement and brushed on

SBR is much better than PVA, but also a good deal more expensive.

(b) That silicone Water Seal Ultra (although I see on the can it says
"Don't use on garden rataining walls")



Has anyone used that waterproof PVA on a cellar or similar?

Does anyone know the reason why the silicone water seal says not to
use on retaining walls - what would happen if I sealed the entire damp
area? Is it something to do with needing to use a seal/render/etc.
that is breathable to allow the bricks/mortar to dry? What would be
the risk of sealing a 600*600mm section of the wall, bearing in mind
that I'm happy with the small amount of water entering the garage, I
just don't want it to enter where it can blow the cupboards.

It's probably something to do with the possible build up of water behind
a retaining wall, which could then freeze and.....


I had a look at Sika but it looks too thick and bulky considering I
only need to treat 600*600mm of a 5000*2400mm wall. Thanks for the
recommendation though.

On 3 Dec, 15:56, "
wrote:
Thanks guys. I went to the local Focus to see what they had and
spotted some Thompson's Water Seal which takes care of the penetrating
rain issue. They do two kinds, the normal Water Seal (which seems to
be a stearate-based one) and the Water Seal Ultra which is silicone.
The silicone one does seem to last longer so I was wondering why Chris
dislikes them so much for external garage walls. As long as the
inside can breathe (and it's pretty draughty in there ), isn't that
sufficient?

Regarding the garage/garden retaining wall issue, the two shed
solutions seem to be:
(a) Unibond Waterproof PVA mixed with cement and brushed on
(b) That silicone Water Seal Ultra (although I see on the can it says
"Don't use on garden rataining walls")

Has anyone used that waterproof PVA on a cellar or similar?

Does anyone know the reason why the silicone water seal says not to
use on retaining walls - what would happen if I sealed the entire damp
area? Is it something to do with needing to use a seal/render/etc.
that is breathable to allow the bricks/mortar to dry? What would be
the risk of sealing a 600*600mm section of the wall, bearing in mind
that I'm happy with the small amount of water entering the garage, I
just don't want it to enter where it can blow the cupboards.

I had a look at Sika but it looks too thick and bulky considering I
only need to treat 600*600mm of a 5000*2400mm wall. Thanks for the
recommendation though.

Answer
Any building operation to any part of it ideally should be reversible
(William Morris Ruskin et al SPAB) or as close to it as possible.
Silicone once on will not come off. It will not have a life anything
like that of the building (200 years?) because silicone will degrade
in say 20 years. You will then have a partial "water proof" layer with
water going in faster than it comes out. This is true of oil-based
paints on wood which is why wood degrades faster with them AFTER about
5 years than on microporuous paints.
Brick operates on the basis of a dynamic equilibrium - absorbing water
in the rain and giving it back after. You need to let it carry on
doing this with a reduced not eliminated absorbtion
Hence repellent not proof
Chris

Thanks again. Looks like I'll be getting the basic Water Seal then
for the rain wall.

It's probably something to do with the possible build up of water behind
a retaining wall, which could then freeze and.....

Ah. Best give up on my plans to totally seal that wall then.

I've been thinking about the silimarities/differences between this
situation and that of cellars. I suppose cellars, where they have
been sealed, are underground and under a house, so the water never
actually freezes. Looks like I'll be using some 1mm perspex sheeting
to cover the side & base of the unit then and perhaps some of the
breathable stearate-based sealer on the inside of the wall to try to
stop the seeping. I guess I'll have to leave a small airgap down the
side of the unit which were we live will turn into a spider factory.

if the garden next door is higher than your floor
then i'd get the nieghbour to dig a little trench on their side
rather than dig a groove in your floor, or both,
water loves to go downwards
and will climb up a bit to do it...

access to the outside but best solution is to ask your next door
neighbour for cooperation (technically he is allowing a nuisance in
law and you could force him but clearly that would be ott) and attack
the problem at source. Consider a lead capping on the abutting wall,
similar water repellant treatement and / or lowering of ground (if
that is a problem) insertion of dpm between his abutting wall and
yours etc etc
Chris