Damp internal walls - anti damp paint

[Jules03]

Hi. We're currently renovating an old property and the external walls are quite damp as there is no insulation in the property.

We have looked into solid wall insulation but have decided against it as it the house would be a real problem to do throughout.

Before we get the walls skimmed in certain rooms, we would like to put some sort of anti damp paint on the walls.

Can anyone recommend any?

Thanks

 

[joe-90]

No such thing.

 

[Jules03]

Maybe I've not worded it correctly - previously when we've done an extension on a previous property, we put pva on the walls in preparation for plastering.

Isn't there some sort of sealant that you can put on the existing plaster that has some sort of barrier on or is it just a case of putting pva on?

 

[joe-90]

Neither. You can't seal a wall like that, hydrostatic pressure will force it off.

Forget about PVA - that is the worst choice possible.

 

[Jules03]

It's not that damp.

I've been researching it all day and have seen there was a sealant you could put on external walls - like a weathershield sealant. Maybe I've misread about it. Will have another look.

I just wondered if anyone had any recommendations if there was such a product.

 

[joe-90]

Old houses need to breathe (dry out when they get wet). You are asking for trouble.

 

[stevethespreader]

you could try this on external walls it was being advertised on diynot it says it stops damp coming through but allows the walls to breathe 1st time ive seen it http://www.stormdry.com/?gclid=CO6W0Pz--LQCFXDLtAodPHgAAg

 

[gregers]

that looks like a 'grangers type of product'

 

[dann09]

I'm dead against, i guess, all damp/water sealants. I know that others find them pretty useful, but my take on them is that when they do work, it doesnt last, and sometimes leaves brick or stone slightly discoloured. Elevations facing South and East ( i think) sometimes will have the summer sun, acting on moisture already in the wall (interstitial) "blast" these sealants off the surface.

As a desperate remedy - maybe. But we typically look for causes and treat them, or we walk away.

I sympathise with joe, being asked for a professinal opinion, giving one, and then being told a days research shows different to a lifetimes work experience.
Five minutes research on mixing PVA and H2O might have helped the OP.

Why, when the OP seems to have had this trouble before did they go ahead, do more or less what they had done before, and only now turn for an informed opinion?

 

[stevethespreader]

. One of our more severe tests involved painting the outside of a blockwork sample, then injecting water inside ... the water gradually escaped and needed to be topped up, but certainly over a month or so there were no signs of any blistering in the Anti-Damp paint.

what other tests have you done other than put it on blockwork? have you tested it on lime old lime walls ect?

 

[CooVarchris]

. One of our more severe tests involved painting the outside of a blockwork sample, then injecting water inside ... the water gradually escaped and needed to be topped up, but certainly over a month or so there were no signs of any blistering in the Anti-Damp paint.

what other tests have you done other than put it on blockwork? have you tested it on lime old lime walls ect?

Steve - nothing on lime walls, but if it's a problem and the demand is there, we're happy to look into it. We tested the block work and brickwork, plus an extended test this year on a Landlord's property which had very bad damp / condensation problems.

 

[stevethespreader]

. One of our more severe tests involved painting the outside of a blockwork sample, then injecting water inside ... the water gradually escaped and needed to be topped up, but certainly over a month or so there were no signs of any blistering in the Anti-Damp paint.

what other tests have you done other than put it on blockwork? have you tested it on lime old lime walls ect?

Steve - nothing on lime walls, but if it's a problem and the demand is there, we're happy to look into it. We tested the block work and brickwork, plus an extended test this year on a Landlord's property which had very bad damp / condensation problems.

maybe it would be a good thing to state on the side of the tin what background its been tested against or not you don't want people putting it on things that may have adverse effects, also just because the water you injected into the block dried out doesn't mean to say that that block was still able to breath

 

[CooVarchris]

We kept the moisture content in the block up by regularly injecting water into it ... it wasn't just a case of letting it dry out.
How much or how little info on the can or TDS (Tech Data) is an ongoing dilemma? Some customers are like sponges, eager for any snippit of information, others get turned off by anything more than a few sentences. Bear in mind for us, it is a relatively new product and learning exactly what it can or cannot do will be work in progress ... believe it or not, even when we think we know a product 'inside and out', customer's often find novel uses for it that we never even considered.

 

[stevethespreader]

your link seems to have disappeared along with your post not sure why, anyway what im getting at or trying to say is that if that's all the tests you have done on your product then i feel that your product has not been tested enough, it looks like you have put it through certain tests and leaving it to the imagination of the buyer weather it will be good for the application he needs it for or not, after all it dosent say what to use it on does it--- or do it?