Damp proofing failure

[paceyjg]

Back in 2006 we had our old miners cottage damp proofed (exterior walls injected, interior walls tanked) We then re-rendered and plastered following the Damp proofing companies instructions.

In the last year the interior walls have become increasingly bad, particularly around a disused fireplace, so it looks like the tanking has failed.

I don't expect I will get much joy from the companies guarantee as I am older and wiser now but can anyone recommend maybe some sort or sealer I can paint over the walls before I redecorate? The property is rented out so I have to go in every couple of years anyway for general maintenance.

I have enclosed some pictures of the rising damp.

Thanks for any advice.

 

[stevethespreader]

What construction is the cottage?

 

[paceyjg]

Solid stone, no dpm or cavity.

 

[stevethejoiner]

If its rented I take it it is not occupied by you, and not just empty? Is there any damp at high levels? Are you sure its rising damp, not condensation. If you have no control of heat and ventilation, is the house sweating? and if so with solid stone walls condensation could be settling in those cold spots? How long has this been going on for? What heating do they use? Where is tumble dryer? Is there permanent ventilation? Are the tenants opening windows?There are so many things that can contribute.

 

[stevethespreader]

Injecting and tanking solid stone is not the best option you have created a barrier that prevents it breathing so all the moisture from the inside from everyday living has nowhere to go forming condensation as said above when the warm air hits the cold walls you have a problem, I'm not saying that this is def the cause but it could be and its going to be hard to rectify .

 

[paceyjg]

I am taking steps to improve the ventilation (the chimney was capped inside the roof space with no vent) so that has been unblocked and a vent tile put above in the roof. Pretty sure its not condensation, however.

 

[stevethespreader]

Your not supposed to inject or tank stone its a natural product and it has to breath so it shouldn't have been damp proofed , the integrity of your cottage has been compromised , I think you will see no difference putting an air vent in the roof

 

[ree]

OP,

As advised above, dont be putting any air vent in the roof.

Are you saying that your chimney stack has been dropped below the roofline?

Chimney flues need sweeping whether they are redundant or active.

Flues need to be vented top and bottom.

It appears to be liquidised chemicals from the sooty flue coming thro to the decorated surface. There might also be rising damp from the soil filled hearth, or even from under the solid floor if no membrane (DPM) is present under the concrete.

If your fire opening is blocked then it will need opening up for sweeping the flue - it can be opened up anyway when you remove all contaminated plaster to 300mm above any damp signs.

Is this a rendered outside wall(s)?

There are various kinds of condensation OP, how would you know the difference?

 

[paceyjg]

Had someone look at it, it is rising damp back.

The chimney stack was capped below the roof line so we have re-opened that and a tile vent should allow extra ventilation into the house, which can't be a bad thing whilst it is rented out.

A damp course chap recommended stripping all of the render back off and starting again, something I am not prepared to do at this time, so a temporary fix will have to do.

Either:
Sand, seal and repaint (maybe an alkaline paint to seal) or
Dot and dab some poly backed plasterboard to the worst walls and skim.

Unless someone has another idea?

I know that neither of these are permanent fixes but I guess the best long tern option would be to re-render in lime or something breathable, and as I said its not really a goer at this time.

 

[stevethespreader]

Your joking? Dot and dab worst walls? So your going to put adhesive on damp walls? It won't last 2 seconds , also I would not trust what your so called damp proof expert is saying for one if he knew anything he would tell you that your stone walls should not be injected or tanked , you may be older like you say but your def none the wiser I'm afraid

 

[paceyjg]

Your joking? Dot and dab worst walls? So your going to put adhesive on damp walls? It won't last 2 seconds , also I would not trust what your so called damp proof expert is saying for one if he knew anything he would tell you that your stone walls should not be injected or tanked , you may be older like you say but your def none the wiser I'm afraid

Thanks for you input.

Anybody else please?

 

[stevethespreader]

As a token of my good will I present you with this link I'm out http://www.heritage-house.org/managing-damp-in-old-buildings.html