More damp stuff..

[sara101]

Hi,
We've just bought an old cottage in Herefordshire. The survey picked up damp and strongly suggested we dug up the floors and put in a DPC. Luckily the mortgage lenders were prepared to reduce the amount they were prepared to lend rather than impose a retention, so we have a choice about what to do. I wanted to ask a couple of questions (to start with ); the painted kitchen walls have got a bobbling effect up to about a metre all round (photo attached).. what is the best course of action to deal with this? Second, the pantry floor in the corner is damp and mouldy (see photo)..the left hand side and back of house are built into a bank so we can't do anything about external ground level.. any ideas? The house is actually quite cosy considering and with some airing and sunny days, it doesn't feel damp at all.
This is a bit rambling - sorry, but any advice would be great,
Cheers,
Sara

 

[AMc]

Hi Sara,

First can I point you at the cunningly hidden Damp FAQ thread?
http://www.periodproperty.co.uk/forum/viewtopic.php?f=6&t=6777
It covers a lot of ground.

My first instinct where you have paint blistering due to moisture is it's probably a modern finish.
Breathable (aka water vapour permeable or microporous) paints like limewash and distemper allow moisture to move without damage - letting the building "breathe" ground moisture, absorb condensation and let it evaporate off.

The chances are you will need to strip back that paint and let the wall dry before you can redecorate with an appropriate finish - but as with many things on a period home - take you time to work out the most probably causes of the problem and the least damaging ways to fix it before you start.

Also take advantage of the warm weather to let the air into the house.

 

[Carol]

Welcome to the forum, Sara.
Damp is one of our favourite topics so you can expect lots of suggestions.

We had lots of damp when we arrived and the first and easiest to sort out was lowering the ground on the outside which was just earth flowerbeds. Have a good look around outside and check on guttering and downpipes, best to do when its raining, and you may see something obvious like cracks or leaks, we had a waterbutt which was leaking from the back which caused our neighbour no end of trouble before we realised. Floors and walls take a bit more effort but it can be done!

And try not to worry, I think all surveys pick up damp in anyhting older that 25 years.

 

[MdB]

.the left hand side and back of house are built into a bank so we can't do anything about external ground level.

Any particular reason why you can't do anything about this? I would view this as being one of the main causes of your damp so anything that could be done would improve matters even if it wasn't possible to go all the way down the wall.

 

[robgil]

Those photos look to me like the house needs aired a little. I would also say to strip the paint , allow the wall to dry out over the summer and then re-paint with a breathable paint. You could limewash it but it looks like you may need something stronger in those rooms, perhaps distemper? There are lots of other breathable paints on the market.
These guys could advise better than me on what paint to use for a particular room. http://www.mikewye.co.uk/ , I just tend to lime wash everything.

R.E. the ground level , unless this high ground level is a recent addition to the cottage I would assume it isnt causing excess damp , it certainly wont be helping but if the ground is draining properly (away from the house), there isnt any leaking guttering and the other side remains able to breath and allow moisture to pass through I would strip any paint off it and see if it dries out.

I wouldnt go lifting those flag stones unless an absolute last resort. They are probably laid to earth and you would have to fork out a lot of money to cover up a damp issue rather than get to its source and fix it from there.

The efflorescence on the brick floor should clean up easily enough , it just looks as though its been left to sit damp for a while.

Welcome to the forum by the way , There are enough of us here who have had to deal with damp issues and flooring issues so hopefully between us we should be able to help.

 

[Penners]

Damp is one of our favourite topics

Welcome from me, too, Sara. I'd just like to make a slight correction to Carol's use of the word "favourite". I'd perhaps change that to "ubiquitous" - we don't like it, but we hear an awful lot about it! :wink:

I subscribe very strongly to MdB's point-of-view. Probably the best thing you could do, to start resolving your damp problem, is to get that soil away from the two banked-up sides of the house. Is there any way that you could cut back the soil and hold it back with retaining walls? If not, then there are systems that can be installed against the wall that allow the soil to rest against them, but still permit the wall to 'breathe' - broadly they consist of a sheet of dimpled or ribbed plastic. The project is more complicated than this, but that's the fundamental principle.

As AMc has said, you would also do well to remove any cement or gypsum wall coatings internally, together with any modern, impervious paints.

However, I would think very carefully about installed a damp-proof membrane under your floor. You may protect the floor from upwardly permeating damp, but that can have the effect of forcing the damp sideways until it meets your walls, which can then channel it upwards. So the result can be drier floors - damper walls.

Finally, returning to Carol's and AMc's comments again, take advantage of the summer to air the place as much as possible - you need to get warmth and ventilation throughout the damp areas. And check for any and all possible sources of water ingress - dodgy guttering, poor rendering, roof and flashing problems, gaps around door/window frames... all that kind of thing.

 

[sara101]

Hi, thank you everyone for your helpful comments (and sorry I overlooked the damp thread )
We will remove the paint and leave the Walls to dry out over the summer. Unfortunately we cant do anything about the external floor level as it is a tarmac road- the first floor is the ground floor from outside at the right and back. Lovely, reassuring advice about not lifting the floor. That is just what we wanted to hear ))
Sara

 

[Penners]

we cant do anything about the external floor level as it is a tarmac road

Ah yes - that can make life trickier!

One thing you might like to do sometime is to watch what happens to the surface water on the road in wet weather. If the camber is sending it all over to your side, or the drains are ineffective, then you might have a case to start talking to the council. Maybe you could post a few photos here, so we can see the arrangement of the road in relation to your house?

 

[sara101]

Hi, here is a photo showing the layout...Not sure that we can do much about it.
Sara

 

[masochists-r-us]

Hi Sara,
Understand the issues with the tarmac road, but have you done everything you can to reduce the ground level on the other two sides which appear to be within your boundary? I'm also with previous posts that reducing the ground level outside should be the single most effective step you can take.The next two would be to ensure you have adequate heating and ventilation in this area. If these have been lacking in the past, it will take time to dry out.
If you have done all of that and still have a problem, it would be worth talking to the council and maybe considering a french drain. However,this will cost you, I suspect.
As has been echoed in the past, slowly,slowly,step by step is the best way to approach damp issues.
Beautiful stone flags, by the way. Agree with others. Don't lift them for anything.

 

[Penners]

m-r-us - before considering any reduction in ground level on the other two sides of the house, I think Sara needs to know whether the ground on those sides is higher than the internal floors. If it's not, then lowering ground levels may be superfluous.

Sara - it's difficult to see clearly on the photo, but is there a fillet of mortar running along the line where the tarmac surface of the road meets the stone wall of your gable end? If so, then it might be an idea to inspect this fillet closely, particularly when it's raining hard. Here are some pointers:

Firstly, does the fillet actually exist, or have I misread the photo?

Is the fillet doing an effective job of preventing the surface water on the road from soaking into your wall?

Are there any cracks in the fillet?

Is it high enough to stop water from sloshing over the top of it?

Does the fillet really seal properly against the the tarmac, or could water seep under it and into your wall?

It looks as though the fillet stops just after the point where the gable wall of the building becomes a garden wall. Unless there's a vertical DPC where the garden wall meets the building (and I can't see one) then water could soak into the garden wall where the fillet stops, then sideways into your gable wall. I would want to see the fillet continued at least as far as the corner.

I'm not sure what your legal rights are, as regards this situation, but it seems to me at least morally right that the council should do everything reasonably possible to stop the water falling on their road from affecting your wall. So if you suspect that the fillet isn't doing its job, then I think you have a case to ask for it to be improved.

I'm not suggesting that this is going to be anything like a complete solution to your problem, but in your situation I think you have to look for any detail that can help improve it.

 

[masochists-r-us]

m-r-us - before considering any reduction in ground level on the other two sides of the house, I think Sara needs to know whether the ground on those sides is higher than the internal floors. If it's not, then lowering ground levels may be superfluous.

Sara - Mr P is quite right. I have probably assumed that your external levels are higher than the floor having seen it so many times before ( in fact, we have a current example of it still to be remediated in our property). Definitely no point digging out if that's not the case. In any event, best of luck with it.

 

[robgil]

I dont think you have a damp problem there , I think it was condensation gathering when the house was empty.
The only things you can do would be to inspect where the tarmac meets the wall and make sure its sealed, Inspect that drain and make sure its not blocked , make sure the pointing on the gable end wall is working, take off the pain on the inside of the wall and let it dry out and keep the place ventilated.

If none of this works then you need to consider other tactics such as inspecting the drain to see if it has collapsed internally, but I would start with the easy stuff first.Your house wasnt always damp and the high ground levels have been there for donkeys years. In fact looking at the way the wall rises with the ground level i would say the high ground levels have always been there, certainly as long as that wall has been there.

 

[Penners]

Your house wasnt always damp

Hmmm... may or may not be true, Rob.

But I entirely agree that, when it comes to solving damp, it's always best to start with the simplest, cheapest jobs first.

 

[robgil]

Surely if that wall was damp for 250 years there would be very little of it left?
Perhaps it was damp however the buildings ability to breath and stay ventilated dealt with it in such a way that it wasnt a problem? The bubbling pain would also suggest moisture trying to seep through the wall but hitting a barrier.
There shouldnt be a high water table there and the tarmac should be keeping the ground relatively dry so I cant see the moisture content behind the wall being too excessive.

edit , I have no idea why I keep spelling paint without a 'T'.

Another edit = what is on the ground in the yard on the other side of the wall?

 

[Penners]

Surely if that wall was damp for 250 years there would be very little of it left?

If it was East Anglian clay lump, then you could be right. But stone walls are made of sterner stuff.

bubbling pain

I tend to get that after eating curry.

 

[robgil]

Ah stone walls , thats just posh that is.
Curry , that just made my mouth water that did , must be tea time.

 

[JoceAndChris]

I don't think they had the same attitude to damp 200 years ago. My house is also built into a hillside, with the back kitchen partially sunk - so floor levels way below ground level. It's often pretty damp down there - puddles of water on the floor - I'm sure that's always been the case. The stone walls hold out despite being damp. Dr C, historic buildings expert and MD of the local firm who repair places like Lincoln Cathedral and Harlaxton Manor, said a French drain wasn't quite what was needed - he suggested replacement of concrete slabs outside with flagstones, and the installation of a gully leading to a soakaway, he said this would better help to protect the sunken wall from becoming saturated as the water flows off the hilltop during rain.
Good luck with your damp Sara, I echo the excellent suggestions made in the thread regarding not lifting floors and using heating and ventilation to dry out the house.
Unfortunately many companies out there are just preying on people's fear of damp and their expensive methodology does nothing to actually alleviate it.

 

[sara101]

Hi,
Thanks again for all the enthusiastic and helpful advice! We'll have a closer look where the tarmac meets the walls on the righthand side and back of the house and see what happens with rain water.

The front external ground is level with the internal floor at the front and on the left hand side is a drop down to a cellar door accessed from the outside, so that is very dry!

We will have a Spring and Summer of airing and removing bobbly pain(t) and then see how it looks/feels.
I'll keep a photo diary of progress

 

[Schoolmarm]

Also have a look if the tarmac slopes towards that back wall at all. It will be higher than the original back street and no doubt the cobbles will still be underneath somewhere set at the "correct" height.