Damp walls...

[CatherineB]

....well, not exactly surprising. If I must go peeling away corners of the wallpaper, what do I expect?!

OK, we have various shades of mould growing on a first floor internal wall, which backs onto a chimney stack. Said chimney's fireplaces have all been blocked up, with no ventilation bricks etc, and no cap at the top. So I'm hoping that fixing this damp is a simple matter of capping and ventilating, then letting the wall dry out. Please tell me I'm right?!

But we also have a small patch of apparent damp on an outside wall, front of house at about knee height as I'm standing in the room. The floor heights are well above ground level, there is a slate damp proof course which the surveyor thought was doing its job, and there are ventilation bricks under the floor level, which are generally not blocked by vegetation. Except, she says, re-examining front of house photo, for one plant climbing up that exact stretch of wall. Is it likely that this plant could be blocking a vital ventilation brick, or if not what is the likely cause? There is no window above it.

All advice and suggestions are welcome! And meanwhile, I shall refrain from picking at any more wallpaper - although these were the only bits in the house that looked like they wanted picking (a bit like scabs, I suppose )...

Thanks

 

[JoceAndChris]

It's impossible not to pick at things isn't it? I always want to have a look behind old wallpaper and plastic paint - so I don't blame you at all!

I don't know anything at all about the capping of chimneys I'm afraid, but that does sound like a likely cause.

Your patch outside the house at knee height - have you observed how the gutters behave themselves when it rains? Is there a persistent drip in that place perhaps?

 

[CatherineB]

Ooh, good point Joce! Not sure about dripping pipes, I will have a look next time we're there (plenty of rain here to show it at the mo!), but I think there might be a pipe running down that stretch of wall.

Off to pick some toenail varnish, now... much less dangerous! :roll:

 

[FamilyWiggs]

Also check where the chimney stack comes through the roof that the flashing etc is all sound. It's possible that water is tracking down the outside of the chimney - we've had that problem in the past.

 

[Penners]

Yes, the chimney should be capped, but you should ensure that it is well ventilated top and bottom. As FW says, also check that your flashing is sound.

If the multi-coloured patch is very wet plaster, it's probably best to hack this off, then let the masonry underneath dry for some weeks/months before patching the plaster.

The downstairs wall is more questionable. The air brick isn't strictly there to keep the wall dry, but to ventilate under the suspended floor. Joce's suggestion to check for any kind of external causes - faulty guttering, leaks, drips, failed pointing etc. - is very good. Also check to see whether there are any internal pipes (eg: central heating) that might be leaking.

If none of this seems to be responsible, then it becomes more problematical. And I'm inching towards a suspicion that there may be a failure point in your slate DPC.

But check everything else very carefully first. And remember that Mr Water is cunning devil - he can make his appearance quite some distance away from where he sneaks in.

 

[Nigel Watts]

After all this rain I have been poking about and sniffing around in search of signs of damp and have found more than I expected, as a well as a badly rotten bottom rail on one of my sashes (a replacement, not an original).

Reinforces my view that the exterior paintwork, render, flashings etc are well overdue for attention.

 

[Nigel Watts]

Just cut out the timber in my badly rotten sash rail in preparation for splicing a new piece in. All is being done in situ with the glass still in so I am not sure how effective the repair will be. Getting this sash out (it's on a landing and extends up to the landing above) would be a real pain and certainly a two-man job. I propose to use wood hardener to consolidate the (not very) old wood before glueing a new piece in, dovetailed at the ends, with slots for the vertical tenons which I will later rewedge. I need a glue which will tolerate a less than perfect marriage of the surfaces. I have some PVA which says it will "foam" to fill modest gaps. Should I use this, or something else?

 

[Penners]

I need a glue which will tolerate a less than perfect marriage of the surfaces. I have some PVA which says it will "foam" to fill modest gaps. Should I use this, or something else?

Are you sure it's PVA and not PU glue?

Polyurethane glues foam somewhat, and are therefore quite useful for a bit of modest gap-filling. They are also weather-resistant, so good for exterior jobs - in fact you need to damp the glued surfaces slightly to improve the "activation" of the glue.

But do be sure that you cramp the two parts together well, while the glue is drying. If you don't, the foaming action can push them apart a bit.

By the way, wear latex gloves or something similar. PU glue is a b*gger to get off your hands.

 

[Nigel Watts]

You are quite right - it is PU not PVA. I have never used it before so the tips are very helpful.

 

[CatherineB]

...and more of them!

Now one of the attic bedrooms has a wall that is visibly damp. I would say it was not visibly damp when we bought the house a month ago (it was not picked up on the survey report either, although that wall would not have been covered), and we haven't noticed it before today despite regular and frequent visits, so I'm concerned there may be something fairly drastic going on there.

Behind said wall in that room, the central chimney wall, is a back boiler. Now I have never had one of these before, and cannot for the life of me understand why anyone thinks it's a good idea to put a boiler behind a chimney, together with gas and water pipes going to and from it, and then brick it up so it's completely inaccessible. WHY WOULD YOU?!

So, I have several suspects, the boiler (which we have not switched on since we bought the house) and its associated pipe works, the two (or is it three) water tanks in the roof above and their associate pipeworks, a hole in the roof, or good old rain down the chimney.

I am really worried about the speed with which this wall seems to be getting visibly, and feelably (is that a word? Penners? I know - tangibly!) WET. And I am REALLY worried because the room below is the lovely bedroom that we had just decided would be ours, and might be next for the drip...

We have set aside quite a lot of money for reroofing, reglazing, reboilering, and doing exciting things to extend the kitchen/dining room, but I can already feel the budget straining! Not to mention the timeline before we can move into our lovely newold house...

Not really sure what the question is, really! Maybe just a moan
No, I am sure - where on earth do we start, trying to find out the cause of this particular wet?!

 

[MatthewC]

I suggest you get a plumber in who can check the tanks and back boiler for leaks - at least for your own peace of mind.

If it's a hole in the roof, then presumably it has been there for a while? Possibly it is only now becoming apparent after the heavy rain recently (depends where you are). We have just today exchanged on a house with lots of damp and at least three holes in the roof, and all the recent rain has been driving me mad as I couldn't do anything about them (except plan).

 

[Nigel Watts]

It could be a problem with the roof flashings. We had our roof completely renewed in Welsh slate and shortly after I spotted damp penetration on the party wall - most irritating. The ingress of water however is very infrequent and only occurs in stormy weather. I am pretty sure this is because proper storm flashings were not fitted.

 

[CatherineB]

Congratulations on exchanging, Matthew, looks like you are taking on quite a project - I thought mine paled into insignificance, but not quite so sure now! Still, it's exciting, isn't it?

If it really is rain (and we have had some heavy this month, but not more heavy than, say, in August), then replacing the roof will fix it.

Will get in the roof to check the tanks at the weekend. But seriously, how DO you check a back boiler for leaks? It's completely plastered in!