Best way to deal with rising damp

[bottle top]

I currently have a small amount of rising damp and a small amount of what I would call lateral damp coming into my 1890 mid terraced house from a rear garden wall.

I have had different advice off builders/damp proof specialists on the best way to deal with the damp.

Guy number 1 wants to inject chemical damp proof course, strip back to brick and render/plaster with required chemicals to prevent salts coming through,etc.

Guy number 2 wants to strip back to brick in both cases of damp and use plastic membrane to contain damp followed by plasterboarding. Guy number 2 is significantly cheaper and will not use a damp proof course stop the damp coming into the house.

Any experts on here with a suggestion to what is the best way to treat damp?

Thanks.

 

[JohnD]

photos please

 

[bottle top]

Ok. So the first pic shows the lateral damp and garden wall through window. Damp is not rising from floor. No pipes by it, etc.

Second pic shows example of rising damp. Spoiled paintwork,etc.

Thanks

 

[endecotp]

Do you ever see any black mould on the surface of the wall?
What about salts?

 

[bottle top]

Never seen black mold anywhere in house. Not sure how to identify the salts.

 

[dishman]

Second time I have posted this today.....

Get someone in who knows what they are doing, rather than being there to sell a product.

I would be sceptical of both options you have been given.

I posted links to these two videos in a another post.

I have no reason to disbelieve what he says.

So, before rushing to solve the problem by throwing lots of money at it, ensure you look at everything melodically, do your research and get a surveyor who knows what they are talking about.

 

[JBR]

ensure you look at everything melodically.

Can you whistle or sing?

 

[bottle top]

Thats the problem I guess nowing who knows what they are talking about. Interestingly enough the youtube guy mentions peter cox and tanking. A surveyor from peter cox surveyed my house a while back and said it was rising damp in Pic2. Pic1 he said it was natural for damp to come into the house via garden wall. And we needed to go back to brick inside where damp is and tank wall. He said not to bother with vertical DPC on garden wall and just put some more coping stones on top. I thought he knew what he was talking about.

Still none the wiser on what to do to be honest. One thing for sure hacking back to brick and leaving to dry out is probably not an option for me.

 

[dishman]

Can you whistle or sing?

That is probably the best malapropism I have had the fortune of mistyping.

-----

This issue is that people tend to believe the quick fix/magic wand solution.

More often than not it seems that damp issues occur when modern building practices are incorrectly applied to old buildings. Whether it be the wrong type of plaster for solid walls, too much insulation without controlled ventilation and so on.

Rather than tackling these issues, which can mean a lot of disruption, someone comes along with a special product which will "solve the issue", cost a lot of money but does not have the disruption factor and can be done in a few days. The usual response is "sign me up".

Needless to say, more often than not, they end up being ineffective, not actually tackling the root cause of the issue, causing further problems in the future and you end up having to get the proper work done anyway.

Maybe look for a specialist in heritage properties. That is what the guy in the vido seems to specialise in. See if there is a similar firm in your area.

Watch his video on the use of damp meters. As he says, avoid any firm that uses the yellow looking simple one with a two prongs. It is not designed for this type of damp detection work.

 

[vinn]

dishman, good post, you hit the target but I would be cautious about relying too much on Peter Ward the Heritage guy.

Electronic MM's of whatever colour or prongs are excellent diagnostic tools in the right hands - otherwise, like any other tool in inexperienced hands they can be duff.

The Heritage guy doesn't strike me as a tradesman and he's constantly over the top with his claims.
However, he has attacked the D&T Co's which is all to the good, and he has taken the trouble to post some informative vids etc.
But think through what he has to say, & how he uses electronic instruments?

 

[dishman]

True, I am usually cautious myself with regard to youtube experts. I cannot confirm if all of what he says is 100% correct, hence I said always do your own research.

But from what I have read, the guy (although a bit ott) does seem to talk a lot of sense. This is also backed up by things I have read else where.

What is true is that in the vast majority of cases, damp injection, tanking etc. especially on old single skin properties, is not the way to go.

While I do not doubt the usefulness of the damp meter in question. I have read before that those yellow (that type always seem to be yellow) small pronged damp meters are not to be used to test damp in walls. As he said in the video, they are to test moisture content of wood in specific conditions. While I do not doubt their accuracy for the use they were designed for, in this instance (like any tool used incorrectly) they can give false readings). I am pretty sure that is correct, I have come across this before.

In that guys videos, you do see him use a the correct meter for measuring damp in the walls. I is in one of his videos.

 

[paul161201]

Try disconnecting garden wall from house and leave an air gap the wall could be pushing moisture into your house

 

[vinn]

"disconnecting the garden wall" would be the way to go. A gap could be created and a sheet of DPC material slipped in. A buttress could be built to give stability after breaking the abutment.

"coping stones" are necessary but, given the garden wall and the house wall are probably sodden by now, copings will only provide a little relief. A lead saddle will also help.

But first the OP could inject a vertical DPC into the garden wall just before it abuts the house - injecting from both sides of the garden wall would be best.
The thing is, injected DPC's are mostly hit and miss so it would be a wait and see experiment.

We dont know if the house or garden wall is rendered or the state of the pointing.

Its quite possible that you have penetrating damp thats rising?

FWIW: Pronged Moisture Meters are neutral: they dont differentiate between wood and plaster or anything else, they merely record the electric activity between the prongs. Experience says what the readings "mean".