Penetrating damp

yakyak

In addition to the problem, I'm thinking it would be a good idea to get the cavity wall isulation removed. I've been told by a damp inspector who came out (who drilled the outside wall) that the cavity wall insulation in damp and the best course of action would to have it removed.

I've no idea who would do this - I've no paperwork from the previous owners as to how long ago they had it done. I also live very close to the coast and I have also been told that houses this close to the sea shouldn't have had the cavity filled.

I'm also not sure if the damp cavity is causing other issues - the joist in the kitchen seem a bit 'dodgy' too. (In that they feel like they are now bouncing)

I'm starting to hate this house!

maninthestreet

That wall only looks like it is one brick length 'depth', from the internal wall to the external wall. Is this enough depth for two brick leaves and a cavity as well?

Kiran

It is, albeit a narrow cavity. Providing the bricklayer cleaned all the mortar snots off as they were building that is enough to prevent the damp penitrating.

Yakyak, 2 thoughts spring to mind, firstly was this work done before or after the cavity wall insulation?

Secondly, it may be worth retro fitting a few air bricks on the elevation that takes the bad weather. The airflow should be enough to keep the elevation dry.

Kiran

Also, when you say the joist in the kitchen is bouncing, do you have a suspended floor? If so, is this ventilated?

yakyak

Hi,

The kitchen floor is suspended. The kitchen was put in when we bought the house 2 years ago, the cavity wall insulation was installed before we bought the house - presumably a long time ago as it looks old! (Brown coloured fibre, which I can see in the cavity in the loft)

The cavity does seem quite tight to me, but I can get my hand in there. (From the gap in the loft)

The previous owners must have recognised this issue as they have had air vents installed along the wall. They aren't blocked either as I can feel a draught blowing whne there is quite a strong wind.

Would the installers of the cavity wall not put somethign around the air vent when installing, as otherwise would it not just be falling out from it? If they did would this mean that the cavity isn't actually getting to breathe?

I'm starting to come around to the idea of having the cavity wall removed. I presume that this is too much for an intermeditate DIYer?

Thanks for all of the help.

Kiran

If it was done before the wall was blocked up then there probably isn't any insulation in that cavity at all (only an educated guess). Is the damp only on that one reveal? The moisture is probably tracking along mortar snot or ties. Are there any vents/weep holes directly outside of the door?

Are you saying you have vents through the wall from outside? If so thats venting the house not the cavity? Can you take a couple of photos outside the house too?

Removing the cavity wall insulation is probably a specialst job because of the kit you need. If the area you have shown on the photograph is the only area you have damp it may be worth removing a brick or two and checking whats inside this area specifically. If its uninsulated in this area air brick and paint the outside with damp sealer would be more than likely all you need.

yakyak

I chipped the mortar from between one of the bricks to get a view of the cavity. I have only chipped away at the height of the door handle, and have used a straightened metal coat hanger to rake some of the cavity out. (Not a lot) The insulation feels quite dry, hopefully the following image shows this:




The other suggestion which has been made to me is that the waste pipe to the left in the picture could be leaking. (Nice!) There are two loos upstairs so the other is being used. The damp patch has dried a bit since it hasn't been used, but that could just be coincidence.

Should I remove some more to look higher up in the cavity? I have tried an endoscope camera as suggested (from ebay) but all I can see is rockwool type stuff.

Would re-boarding as suggested and painting the outside with some breathable sealant do the trick?

Oh and the patch pointing above the door was my attempt in the middle of winter to try and stop the damp patch growing.

Thanks once again.

Kiran

Dry cavity is definitely good news. The leak from the soil pipe is unlikely as the cavity is dry. The problem would appear to be cold bridging and as stated above condensation. If the door reveal is all that is showing damp then reboard the area you've already removed with moisture resistant board and then its a case of improving ventilation. Make sure the window/extractor is on when you cook. Fit some trickle vents to the doubles glazed windows and door. Hopefully that'll be the problem sorted.

Kiran

Just wondering how you got on yakyak?

yakyak

I've been waiting for a bit of a downpour to see how things were, but alas there hasn't been one!

I'll probably be re-boarding the brickwork in the near future - I can't stand the Mrs moaning at me for much longer!

I presume it's possible to get plastic plasterers edge from somewhere. Just to stop a new one rusting again.