Advice on (gulp!) Damp

[cazzz]

Our Grade II listed mid-terraced cottage has a damp problem - caused by leaking gutter by the looks of it. Water has got through the window frame and travelled down through the (cement) render towards the kitchen door. There is effluorescence on the inside of this wall. We have chipped off some of the render and it's obviously very damp beneath. Fortunately the rain has held off giving it a chance to get the air to it. We've also got the dehumidifier on in the kitchen. Not sure what else we can do and would be grateful for any advice including what to use to patch up the chiipped off render - hydraulic lime?
Many thanks in anticipation!

 

[Flyfisher]

First priority should be to fix the root of the problem, i.e. the leaking gutter.

 

[cazzz]

That's sorted. We now need to addresss the hole in the outside wall before it starts raining again!

 

[Nemesis]

Well is it not possible to remove all the render? Probably better in the long term for the building? Then replace with lime?

LBC may be required of course.

 

[cazzz]

That is the long term aim but for the moment the hole will need to be patched up. Presumably cement is a no no?

 

[Nemesis]

Well, cement is a no no, and it's not the weather for non-hydraulic lime, so yes a weak hydraulic may be best.

Or nothing at all? Leave it to dry?

 

[Flyfisher]

It depends on your views of short vs long term. I have some areas of missing render temporarily covered with plastic roof sheeting. This is keeping the rain out while allowing free circulation of air and is doing wonders for drying out the internal structure of the wall.

 

[Penners]

Before you do anything else, I reckon you need to ensure that the wall is properly dried out. I know that's difficult in this weather, but could you arrange some sort of temporary cover over it that allows free air circulation? Then, once the weather has warmed up and you're completely confident that everything has dried out, you can carry our a proper lime repair.

PS: Just realised that I've rather duplicated Flyfisher's advice - sorry.

 

[cazzz]

Many thanks for all your advice. I've taped some plastic over it which I remove in the daytime and when there's no threat of rain!
The hole is only approx. 6" x 6". Presumably filling this with lime mortar when the rest of the render is cement won't cause any problems? I guess the patch will have to be painted with limewash?
Thanks again.

 

[Penners]

Taping plastic over the hole that you have to remove as appropriate sounds a bit second-best, and a hassle for you.

Would it not be possible for you to turn the plastic into a kind of "half tent"? Attach it to the wall above the hole, but then carry it out at an angle, so that air can get up underneath it, but rain can't?

Obviously this would have to be a windproof structure, but I think it would help the drying to take place much more quickly.

 

[Flyfisher]

Or fix a couple of battens at the top and bottom of the hole and fix the plastic onto the battens. This will keep the rain out but give a nice air gap for ventilation. Such an arrangement wouldn't need constant attention and should suffice until the better weather arrives.