I have a quantity of old sandstone, in which I will be building a low-
ish garden wall. The stone came originally from a mediaeval church
window, but has since been cut down to blocks that one or two chaps
can lift.

For longevity, should I be considering using lime mortar in this
construction, rather than using hard cement around soft sandstone?

I've also got nice old weathered faces, and harsh machine-cut faces to
some of these blocks. Any ideas on a quick-ish method to soften the
machine-cut faces?

Cheers
Richard

On 19 Aug, 13:47, geraldthehamster wrote:
I have a quantity of old sandstone, in which I will be building a low-
ish garden wall. The stone came originally from a mediaeval church
window, but has since been cut down to blocks that one or two chaps
can lift.

For longevity, should I be considering using lime mortar in this
construction, rather than using hard cement around soft sandstone?

I've also got nice old weathered faces, and harsh machine-cut faces to
some of these blocks. Any ideas on a quick-ish method to soften the
machine-cut faces?

Cheers
Richard

Around here in North Norfolk, the very soft yellow-brown sandstone is
a common building material. It's also common to see walls suffering
serious sandstone decay - with a skeleton of cement pointing still
hanging in mid-air around it. So yes, at least for the pointing, lime
mortar would seem to be wise. I'd also think about blocking the uptake
of ground water with a course of slate. However your sandstone may
have completely different characteristics.

geraldthehamster wrote:
I have a quantity of old sandstone, in which I will be building a low-
ish garden wall. The stone came originally from a mediaeval church
window, but has since been cut down to blocks that one or two chaps
can lift.

For longevity, should I be considering using lime mortar in this
construction, rather than using hard cement around soft sandstone?


Hmm. what a quandary.


I am not sure it would make much difference. Unelss you got susbisence,
in which case the lime would work nbetter.

I've also got nice old weathered faces, and harsh machine-cut faces to
some of these blocks. Any ideas on a quick-ish method to soften the
machine-cut faces?

hammer and cold chisel, or sand blaster.




Cheers
Richard

"geraldthehamster" wrote in message
...
I have a quantity of old sandstone, in which I will be building a low-
ish garden wall. The stone came originally from a mediaeval church
window, but has since been cut down to blocks that one or two chaps
can lift.

For longevity, should I be considering using lime mortar in this
construction, rather than using hard cement around soft sandstone?

I've also got nice old weathered faces, and harsh machine-cut faces to
some of these blocks. Any ideas on a quick-ish method to soften the
machine-cut faces?

Cheers
Richard

Initial thoughts: Lucky old you! (No stone in this neck of the woods so
garden terracing has been put off and off...)

Then, there's sandstone and sandstone. Do you know what sort it is or where
it came from (geologically). It must be fairly tough if it has lasted from
mediaeval (nice to see the proper spelling) times, though shame the church
had to go.

You might try a drop of acid on a piece of the stone and see if it fizzes.
This would indicate a limy matrix is holding it together, and you might be
able to 'weather' it with a mild acid spray to loosen some of the grains and
then pressure wash them out (mind if it *is* very soft like the acidy stuff
we do get round here, the pressure washer will drill right through it if you
are not careful.). I'd go for the lime mortar if I was you: it lasted many
hundreds of years in the church after all.

Mind you, if these blocks are two man jobbies and your wall is low, and your
stone has nice flat faces, does it need mortar at all, other than as TNP
hints, to soften the stress of any subsidence? You could leave gaps for
plants, and/or drainage too.

S

On Aug 19, 2:24*pm, " wrote:
On 19 Aug, 13:47, geraldthehamster wrote:

I have a quantity of old sandstone, in which I will be building a low-
ish garden wall. The stone came originally from a mediaeval church
window, but has since been cut down to blocks that one or two chaps
can lift.

For longevity, should I be considering using lime mortar in this
construction, rather than using hard cement around soft sandstone?

I've also got nice old weathered faces, and harsh machine-cut faces to
some of these blocks. Any ideas on a quick-ish method to soften the
machine-cut faces?

Cheers
Richard

Around here in North Norfolk, the very soft yellow-brown sandstone is
a common building material. It's also common to see walls suffering
serious sandstone decay - with a skeleton of cement pointing still
hanging in mid-air around it. So yes, at least for the pointing, lime
mortar would seem to be wise.

That's the prime reason such walls are better built & pointed with
lime. However lime is very slow setting, so you cant build far without
waiting and waiting. Common solution is to add a tiny bit of cement,
5% at most, to help it go off enough to build further. There are
better pozzolans to use though, cement isn't a good one.


NT

On 19 Aug, 16:02, "Spamlet" wrote:

Then, there's sandstone and sandstone. *Do you know what sort it is or where
it came from (geologically). *It must be fairly tough if it has lasted from
mediaeval (nice to see the proper spelling) times, though shame the church
had to go.

I don't know the exact source; however, the church will have been in
or around York. It was demolished in the 19th century and the window
re-erected as a folly in a garden. It subsequently fell down and had
to be removed.

You might try a drop of acid on a piece of the stone and see if it fizzes..
This would indicate a limy matrix is holding it together, and you might be
able to 'weather' it with a mild acid spray to loosen some of the grains and
then pressure wash them out (mind if it *is* very soft like the acidy stuff
we do get round here, the pressure washer will drill right through it if you
are not careful.).

Interesting ideas. I was going to have a go with the pressure washer
and see if it made any impression. The stone really is quite soft.

Mind you, if these blocks are two man jobbies and your wall is low, and your
stone has nice flat faces, does it need mortar at all, other than as TNP
hints, to soften the stress of any subsidence? You could leave gaps for
plants, and/or drainage too.

Well, some are two-chap and others are one-chap. Not huge. The wall
will abut a pavement along which children walk to school, so I
wouldn't want anything falling off it!

Thanks
Richard

"geraldthehamster" wrote in message
...
On 19 Aug, 16:02, "Spamlet" wrote:

Then, there's sandstone and sandstone. Do you know what sort it is or
where
it came from (geologically). It must be fairly tough if it has lasted from
mediaeval (nice to see the proper spelling) times, though shame the church
had to go.

I don't know the exact source; however, the church will have been in
or around York. It was demolished in the 19th century and the window
re-erected as a folly in a garden. It subsequently fell down and had
to be removed.

You might try a drop of acid on a piece of the stone and see if it fizzes.
This would indicate a limy matrix is holding it together, and you might be
able to 'weather' it with a mild acid spray to loosen some of the grains
and
then pressure wash them out (mind if it *is* very soft like the acidy
stuff
we do get round here, the pressure washer will drill right through it if
you
are not careful.).

Interesting ideas. I was going to have a go with the pressure washer
and see if it made any impression. The stone really is quite soft.

Mind you, if these blocks are two man jobbies and your wall is low, and
your
stone has nice flat faces, does it need mortar at all, other than as TNP
hints, to soften the stress of any subsidence? You could leave gaps for
plants, and/or drainage too.

Well, some are two-chap and others are one-chap. Not huge. The wall
will abut a pavement along which children walk to school, so I
wouldn't want anything falling off it!

Thanks
Richard

Interesting that you say the stone is soft, as traditionally the
'York'stones would be expected to be fairly hard as cemented with silica,
but it could vary from quarry to quarry, eg:
http://www.myersgroup.co.uk/jwqh/Env....asp?pageID=24

Ah, I miss my old school geology field trips!

S