Damp walls

[CB101]

Hi, any advice appreciated as I do not know who to trust!

I have had a ground floor victorian conversion for 2.5 years which has suddenly developed a strong smell of damp. The toilet has been leaking for a while (now fixed) which has soaked into an internal wall.

Additionally the exterior bathroom wall is permanently cold and sometimes wet (this wall has a lot of cracks on the outside as well as a bricked up doorway).

I have had 3 companies around to look who have given me the following answers:

1) coat the external exterior wall and inject damp proofing into the interior wall and replaster

2) do nothing, it will dry out over time although the exterior wall needs grouting

3) suddenyl a reputable (I think) company has told me that the whole property has rising damp which will costs thousands. They showed me a report they had done on my property 6 months before I bought it which showed the same thing, however my survey (not a full one) did not pick this up. I can see no evidence of damp anywhere outside the bathroom although there is a damp smell everywhere now (it's a small flat) and impossible to tell where it is coming from.
They also told me that the condensation on the windows is a sign of damp - these are single glazed sash windows - is this right?

Can anybody give me an idea of what I should be looking for?

I think I agree with number 2, that the exterior wall needs grouting but would think that the internal wall should be replastered, I don't understand why it needs a new damp proof course when we know that a leaking toilet was the source of the moisture.

I now have companies number 4 & 5 coming but do not understand why their opinions vary so much. Any advice would be much appreciated!

 

[grimrob]

We have a cold wall in our bedroom even after cavity wall insulation.
Now coming round to the thought that we are not adequately heating the room up.
So have put the thermostatically controlled radiator valve up to 5 and noticed a marked improvement.
Another problem can be warm moisturised air condensing on the cold wall and a dehumidifier will help control this.

Hope this info is useful.
Grimrob

 

[JohnD]

3) suddenyl a reputable (I think) company has told me that the whole property has rising damp which will costs thousands.

Companies that sell damp treatments usually tell you that you need them.

Imagine going to a used-car salesman and asking his advice on what form of transport you need.

More damp is caused by condensation than anything else.

Ventilation is always a good start if you have condensation on windows.

Bathrooms usually have a lot of water and steam in them which will cause damp unless you ventilate them thoroughly. A good extractor fan is pretty well essential, preferably one that comes on every time the room is used, by being triggered by the light switch (many people have a psychological aversion to ventilation and will not open windows or turn on fans).

If you ever drape wet washing about your home you are causing such severe damp that you will never be rid of it unless you change your habits.

//www.diynot.com/wiki/building:condensation_in_houses

As a rough and ready guide, if you tape a piece of clear plastic tightly to the wall, and moisture forms on the room side, it is condensation. If the room side is dry and moisture forms on the wall side, the wall is damp (but how it got damp is a different question).

If you stick several pieces up you may be able to get an idea which part of the wall is worst.

 

[CB101]

Thanks Both.

I'm going to try the plastic tonight, Good idea - maybe I need to upgrade the extractor fan (it's old and basic) and turn the heating up before doing anything else.

Appreciate your advice! Company number 3 had caused a mild panic...

 

[weseeyou]

you need to provide a bit more information for anyone to provide a reasonable explanation. I assume that this bathroom is a small rear extension with its own roof ? two outside walls and the third a party wall to the bathroom next door ?

If so it is a prime candidate for a condensation problem which is in itself a big subject area to address in a few lines here.

You really need to have your building surveyed by a trained and qualified professional ie a Chartered Building Surveyor.

So called Damp and dry/wet rot companies rarely employ qualified building inspectors which is why you will always get a different `opinion' about your properties damp issues.

I would suggest first of all that you use a dehumidifier for at least a month in the bathroom to dry the wall out. Natural drying this weather can take up to 1 month per inch thickness of wall.!

Where you have had a former door opening bricked up the chances are that no damp proof course was inserted and that would be a prime candidate area for rising damp. Penetrating damp can effect walls that have earth or concrete paving up against the outside face.

Have a look here for general info http://www.channel4.com/4homes/diy-...-to-spot-and-deal-with-damp-08-05-27_p_1.html

If your flat had a damp problem previously it is possible that in order to sell it the previous owner dry-lined all the internal walls to cover up the damp problem. (cheap short term fix)The smell could be from all the mould that is accumalating in the interstital spaces behind the plasterboard.

 

[CB101]

Hi, the bathroom is an original part of the house, at the back of the kitchen so has 2 outside walls and an adjoining wall. I think that the bricked up doorway may not have a damp proof course.

The latest visitors have found no damp in the rest of the flat but have found damp in the kitchen that nobody else had spotted!

Thanks for the advice, I think a surveyor may be the best way forward to find out exactly what the problem is.

One final question - does anybody know if rising damp ever gets worse or is it something that can be left for a while? Everything I have read suggests removing plaster to a height of 1.2 m, suggesting it doesn't go any higher??

Thanks.