sandblasted interior stonework. What now?

[confused of chalus]

We've had the stonework in our barn conversion (well we've started it !) sandblasted and want to seal  the stone and chaux to keep it relatively dust free and enhance the beautiful stones. Someone told us to use diluted PVA but I am worried that this will stop the wall breathing. Has anyone any experience/ideas? You were all such a great help when we were insulating between the roof beams that I thought we might tap into your experience again! [:D]

[Ron Avery]

It will only stop the wall "breathing" if you paint PVC over the joints inside and outside.  As long as you use a lime mortar for the external  joints I don't see a problem with diluted PVC on the stones, myself I would not bother as even stones with that on still get dust on them.

[just john]

you could try either patio sealer (cheap) or floor tile sealer (trop cher), they will change the colour of the stone a bit though, so take a hidden bit and try it out.

[Théière]

Any PVA diluted or otherwise will stop the walls breathing and will probably yellow or even brown with age.

Use a lime wash, available in many tints and gives a really nice glow.

[Alex H]

[quote user="confused of chalus"]We've had the stonework in our barn conversion (well we've started it !) sandblasted and want to seal  the stone and chaux to keep it relatively dust free and enhance the beautiful stones. Someone told us to use diluted PVA but I am worried that this will stop the wall breathing. Has anyone any experience/ideas? You were all such a great help when we were insulating between the roof beams that I thought we might tap into your experience again! [:D]

[/quote]

Don't use anything but chaux (lime) - as teapot says limewash is the thing to use and you can colour it in any shade you want.

If you seal it with anything, you will be sandblasting again in a few years [:(]

[Ron Avery]

[quote user="teapot"]

Any PVA diluted or otherwise will stop the walls breathing and will probably yellow or even brown with age.

Use a lime wash, available in many tints and gives a really nice glow.

[/quote]

How exactly do walls "breath" through  solid stones?  Surely any air or moisture goes in and out via the joints?

[pachapapa]

The idea of a wall "breathing" is technically a misnomer but serves to convey the idea that an accumulation of dampness will not occur; returning to the concept of the humble single stone and taking as an example a piece of granite contained within a damp wall, the stone will gradually disintegrate and can eventually be crumbled between the fingers. The granite cornice or coin will remain in good health. The degradation of metamorphic rocks is of petrological interest, the quartz,plagioclase and mica in a granite being a classic case.

 I refuse to be drawn into a poinless argument on PVA "glue"; other than to say:

"God the farther, God the sun and Unibond!! 

[Alex H]

[quote user="Ron Avery"][quote user="teapot"]

Any PVA diluted or otherwise will stop the walls breathing and will probably yellow or even brown with age.

Use a lime wash, available in many tints and gives a really nice glow.

[/quote]

How exactly do walls "breath" through  solid stones?  Surely any air or moisture goes in and out via the joints?

[/quote]

Well, he'll be covering the joints won't he?

[WJT]

[quote user="pachapapa"]

The idea of a wall "breathing" is technically a misnomer but serves to convey the idea that an accumulation of dampness will not occur; returning to the concept of the humble single stone and taking as an example a piece of granite contained within a damp wall, the stone will gradually disintegrate and can eventually be crumbled between the fingers. The granite cornice or coin will remain in good health. The degradation of metamorphic rocks is of petrological interest, the quartz,plagioclase and mica in a granite being a classic case.

 I refuse to be drawn into a poinless argument on PVA "glue"; other than to say:

"God the farther, God the sun and Unibond!! 

[/quote]

I too need too am interested to know the best solution. So Pacahapa is "God the farther, God the sun and Unibond" a thumbs up for PVA or not? [8-)][:D]

I know nothing about this but I thought chaux was powdery, therefore, I cannot imagine how it would help in this situation. Tandempilot, when you say you can colour it any shade you like, do you mean for example paint the stones white versus their natural colour? Or can you use chaux over the stones without colouring them?

[Alex H]

This is often a very contentious subject for those who think they know the correct answers. I for one do not care about anyone's elses version of what is right, so I will put forward my case [:)]

When we bought our French 'house in a barn' we saw that the construction inside and out, was stone walls held together with chaux. Coming from a country where cement is king, I did some investigation and eventually my wife and I both went on a weekend course here http://www.lime.org.uk/. The website contains lots of information about chaux. how to use it and the myths that surround it. I have used the knowledge gained from the course to renovate our kitchen which was totally coverd in blue paint, back to the traditional finish. Unfortunately we do not have nice big stones in the walls (more like rubble) so we limewashed the resulting surface.

[IMG]http://i196.photobucket.com/albums/aa288/alexhudghton/kitchen_before.jpg[/IMG]

[IMG]http://i196.photobucket.com/albums/aa288/alexhudghton/kitchen_after.jpg[/IMG]

My sister has a simliar build house which had the kitchen wall painted (emulsion). Due to damp on the wall itself and creeping mould she has had the wall sandblasted and will limewash over it.

[just john]

Simple stuff really, the stone, chaux and limestone especially is all porous and enables the permeating damp of the wall to rise and escape into the atmosphere inside and outside, when the interior wall is dry then dry powdery dust forms and brushes off onto clothes, furniture etc. you can reduce this with PVA, or sealers but of course the damp cannot evaporate through the sealer. I am a believer in sealing the walls up to metre, the damp can escape to the outside if that is unsealed or above the metre line, it does need to escape though or will have an adverse effect on the stone and chaux. We had a drainage channel dug around the outside of the walls to assist the drainage and avoid the dampness, (some still penetrates from outside according to the direction of the storm) but the stone look is preserved and dust reduced.[8-|]

[confused of chalus]

Thanks for all your answers. But the whole idea was to have the stones looking like stones  - and the pictures  from Tandem Pilot confirmed what I suspected from the other posts that limewash will cover them. Is there no way to use a transparent product that will enhance the look of the stones (like when they are wetted) without storing up trouble in the future. And no - I dont ever want to sandblast again! Sorry to be a pain, and I'm sure all the renovation purists out there will think I'm mad to want this look. It's just that the stonework is so beautiful I dont want to lose it but there is no way I will be able to dust it! Just John says try sealer up to 1 metre but we're talking double height walls to roof line and we dont want to have to go right up to the top more than once every ten years or so!

[Théière]

Like Tandem Pilot I too did a course, my one was at The Lime Centre (click on the link)

You can buy lime wash in various grades depending on the level of damp. One of the walls at the lime centre long barn backs on to an earth bank, yet does not powder or feel damp.  Lime wash can give a translucent finish allowing the natural stone to show through. Other lime wash paints are similar to what Tandem Pilot has used with a more solid pigment.

Why not give Bob a call or email and discuss it with him, he has an MBE for service to Her Majesty for renovating the castles but is a really friendly chap and very knowledgable.

Don't ask him what he thinks of PVA or you will get a reply you may not like [:D]

[Alex H]

[quote user="confused of chalus"] But the whole idea was to have the stones looking like stones  - and the pictures  from Tandem Pilot confirmed what I suspected from the other posts that limewash will cover them. Is there no way to use a transparent product that will enhance the look of the stones (like when they are wetted) without storing up trouble in the future.

[/quote]

No, you missed the point - I have no stones that were worth keeping in the walls - they were all *cr&^p

You must use limewash on the lime but as I understand it you can use other sealants on the stones themselves (such as linseed oil)

Checkout this site for more help http://www.periodproperty.co.uk/  There are many forum users there that are professionals in this area.

[Ron Avery]

[quote user="Tandem_Pilot"][quote user="Ron Avery"][quote user="teapot"]

Any PVA diluted or otherwise will stop the walls breathing and will probably yellow or even brown with age.

Use a lime wash, available in many tints and gives a really nice glow.

[/quote]

How exactly do walls "breath" through  solid stones?  Surely any air or moisture goes in and out via the joints?

[/quote]

Well, he'll be covering the joints won't he?

[/quote]

I actually wrote "It will only stop the wall "breathing" if you paint PVC over the joints inside and outside".[blink]

 

 

[Alex H]

[quote user="Ron Avery"][quote user="Tandem_Pilot"][quote user="Ron Avery"][quote user="teapot"]

Any PVA diluted or otherwise will stop the walls breathing and will probably yellow or even brown with age.

Use a lime wash, available in many tints and gives a really nice glow.

[/quote]

How exactly do walls "breath" through  solid stones?  Surely any air or moisture goes in and out via the joints?

[/quote]

Well, he'll be covering the joints won't he?

[/quote]

I actually wrote "It will only stop the wall "breathing" if you paint PVC over the joints inside and outside".[blink]

[/quote]

Didn't see that Ron Sooooo Sorry [:)]

[confused of chalus]

Thanks for the link, Tandem Pilot. Spent hours browsing! Definitely a site for real purists but the upshot was that it seems pva is not on! They suggest limewater for a transparent seal. Anyone out there tried this? More to the point, has anyone got a recipe.

And teapot, WHO IS BOB?

[Théière]

e-mail: [email protected]

Director: R.H. Bennett MBE

http://www.thelimecentre.co.uk/

[confused of chalus]

Thank-you teapot. will have to contact him for advice.

[Alex H]

[quote user="confused of chalus"]Thanks for the link, Tandem Pilot. Spent hours browsing! Definitely a site for real purists but the upshot was that it seems pva is not on! They suggest limewater for a transparent seal. Anyone out there tried this? More to the point, has anyone got a recipe.

And teapot, WHO IS BOB?

[/quote]

I assume they mean limewash but it may be just as well to ask them [:)] [email protected]

(limewash is simply water + chaux mixed to a consistency of single cream)

[Ron Avery]

 C of C I think some are getting a little bit carried away, you are renovating an old stone house not Hampton Court Palace.[blink]

For years the French used stone to build walls with the stones on each side of the wall set in a lime and sand mix and the centre filled with lime, sand and all sorts of other rubbish,  and a lime/ sand joint filler was used.  Over the years that centre has deteriorated due to the breakdown of the sand/rubbish/lime mix by water ingress.  Why didn't they use cement in the first place? Probably because it was just not available and/or too expensive, so they used what they had.

What French builders do to renovate old stone  walls is to rake out the joints, reset any loose stones with lime/cement/sand mortar and refill the joints with lime/sand mortar to allow movement due to temperature changes, there will be water ingress up to a metre on such walls.  Then if they don't want to look at the stones, the stones are not "pretty" and prevent some interior water ingress they just crepi or render over the lot with a lime/cement/sand render.

You will read that you should only use limewashes and lime/sand mortar, that might be necessary for restoring Leeds Castle for historical accuracy, but is it really necessary in the 21st Century?

Our local library is very old, probably an 19th century converted barn, its used for an national book festival and is being refurbished and extended, the new section has been traditionally constructed with a block interior and traditional stones on the outside using the "traditional" lime/cement/sand for mortar and lime/sand for the external joints.  The interior wals are being plastered.

[Alex H]

[quote user="Ron Avery"]

 , you are renovating an old stone house

[/quote]

Got it in one there Ron, so why not use the materials that were used to build it?

[Ron Avery]

Because there are modern materials now readily available that are far more efficient in doing the same job and unless the interior walls are left bare do not detract from the original look of rough old crepi or plaster!!.  I think there is a difference between a renovation and a historically accurate restoration.

[Théière]

[quote user="Ron Avery"]

 C of C I think some are getting a little bit carried away, you are renovating an old stone house not Hampton Court Palace.[blink]

For years the French used stone to build walls with the stones on each side of the wall set in a lime and sand mix and the centre filled with lime, sand and all sorts of other rubbish,  and a lime/ sand joint filler was used.  Over the years that centre has deteriorated due to the breakdown of the sand/rubbish/lime mix by water ingress.  Why didn't they use cement in the first place? Probably because it was just not available and/or too expensive, so they used what they had. Portland cement invented in 1824 http://www.thelimecentre.co.uk/Library/Best%20Mortar.pdf

What French builders do to renovate old stone  walls is to rake out the joints, reset any loose stones with lime/cement/sand mortar and refill the joints with lime/sand mortar to allow movement due to temperature changes, Something cement will not do which is why brick and cement walls require mastic expansion joints.there will be water ingress up to a metre on such walls.  Then if they don't want to look at the stones, the stones are not "pretty" and prevent some interior water ingress they just crepi or render over the lot with a lime/cement/sand render.

You will read that you should only use limewashes and lime/sand mortar, that might be necessary for restoring Leeds Castle for historical accuracy, but is it really necessary in the 21st Century? Yep when working on old buildings, http://www.thelimecentre.co.uk/Library/limewash.pdf

Our local library is very old, probably an 19th century converted barn, its used for an national book festival and is being refurbished and extended, the new section has been traditionally constructed with a block interior and traditional stones on the outside using the "traditional" lime/cement/sand for mortar and lime/sand for the external joints.  The interior wals are being plastered. 

[/quote]

 

[Ron Avery]

Teapot  I'm sure that what you have writen is totally accurate and relevant to old stone houses and castles in the United Kingdom, which have the climate and conditions contained in the quoted items, like kitchen and open fires to aid the drying out of the walls.

My barn walls had sand, glass, broken pottery and earth in the centre and they had sagged badly outwards due to the weight of the roof and  I have no intention of replicating that mix for historical accuracy!!  50-50 lime/cement with sand mortar has been used extensively in the rebuild giving strength and flexibility and the joints filled with a lime/sand mortar.  I am sure that Cement may have been invented in 1824 in the UK but its availability in rural France to the peasant farmer was somewhat later I think.