Damp in ancient cupboard

[TimHardusty]

Having moved in to our 17th century G2 listed Portland cottage a few months ago, we have just started on the redecoration.

First room is the dining room, which was the downstairs room of one of the two small cottages joined together sometime in the past. We stripped the wallpaper - which was vinyl and, I believe, limiting "breathing" from the walls - to find various areas of damp.

Much of it has dried well now it is exposed to the air - might have to hack off some gypsum plaster repairs and lime plaster it if I get brave - but we were left with damp cupboard - 85% RH at 18C.

In this room, an old front door was blocked up sometime long long ago. At the front, it has been infilled with small stones, and behind that I now know, large stone blocks.

Investigating the damp, I found a hole in the back wall of the cupboard, so I started exploring, and after removal of various wood linings and newspaper "stuffing" (1983, so no interest there) I found the rotting remains of an old door frame - or timber infill - around the large stone blocks that had been used to block the doorway. I hacked away, and have now removed all of this rotten wood.







There is an issue with the timber across the top that I need to deal with, but it is only there to provide something for the boarding that was at the top of the cupboard to be nailed to; nothing structural, thankfully.

I have removed as much of the paint that had been applied to the stone - I don't think it was limewash, more likely a "mould resistant paint" - so it can now "breath" better - and hopefully time will tell whether it becomes a fundamentally drier place.

To the left of the cupboard door modern plasterboard had been used...this was damp, and is now removed. Not 100% sure why it was damp, but I'm clinging to the hope that it is trapped moisture due to the vinyl-coated wallpaper and/or lack or "breathability" of the modern PB that had been stuck over the stone.

My plan is to rework the area to make a cupboard again, and I'm debating whether to batten and board it (with foil lined PB?) or maybe have a go at lime plastering it, or maybe try wood-wool board with a lime plaster skim?

But the point of this post is that I am unsure what to do to fill in the space left empty by the now-removed rotten wood.

- treated timber, and a skim of some sorts?
- modernvbricks, mortared in - but lime mortar or modern mortar?
- or Portland stone mortared in?
- half tempted to use expanding foam, but that's not right of course!

Can you let me know what you think please?

 

[TheForge]

I personally wouldn't use timber, treated timber isn't ideal in an indoor environment and from your description ultimately it is likely to rot again. As the frame serves little purpose anymore, and any history has rotted/been hacked away, I would be looking at a more permanent repair, definitely using lime mortar. I suppose Portland stone would be the most authentic replacement but bricks might be easier as it will involve a lot of cutting to size.

I would avoid boarding as the damp is either condensation due to poor ventilation/cold, thin infill wall, or penetrating through the blocked up door way from outside. Boarding over will likely trap the damp behind it.

If you intend to use it as a cupboard again is it worth the effort of plastering at all? I'd probably fill the hole and just limewash the wall.

 

[worms]

Step away from the foam!

Personally, I would find some suitably sized shards of stone and knock them in with a bed of lime mortar, but then I would be looking for a cheapskate solution! I have done this here with rocks from the garden and they match the rubble stone of the wall - the builders here didn't go far for their materials.

I would give the wall a month or so to see what happens to the dampness before deciding what to do - if you can live with that in the meantime.

And I would be having a look at the two down pipes to check that the external water is actually being taken away from the front wall.

 

[Penners]

I would give the wall a month or so to see what happens to the dampness before deciding what to do

I wholeheartedly agree with worms, except that I would give it longer than a month. The summer is upon us, and the warmer weather should be a big help in getting everything thoroughly dried out. Remove all the deleterious modern materials and leave the cupboard open to allow air circulation. To help this, try to ventilate the whole house well during the summer months - warmth and ventilation are the best possible defence against condensation and damp.

During that waiting time, I would thoroughly investigate the outside wall, to make sure that its pointing is sound and that no other factors are causing/allowing water ingress.

Once you're satisfied that the structure is well dried out and watertight, I would use bits of stone and lime mortar (as worms suggests) to make good the cavities. I would then plaster the whole thing with lime mortar.

It would be a good plan to insert some sort of grille into the cupboard door, to allow air circulation in the future.

 

[88v8]

Agree re ventilation of the cupbd, brass grille top & bottom of the inner door would be good.

The old door frame or at least its outline, is history that would be a shame to lose, so although I also agree with inserting bits of stone - shards, indeed - with lime mortar, I wouldn't then plaster it.

I would do everything around the house with lime mortar & sharp sand. Once one gets into the habit, the temptation to reach for cement/soft sand disappears. If bagged NHL is kept dry, it seems to remain viable indefinitely, so you can always keep some handy. Beware of using NHL that is harder than the stone.

Ivor

PS handsome frontage. Love the jumble of blocks and 'shards'.

 

[MatthewC]

Tim

Do I understand correctly that the damp cupboard is actually in the front wall of the house? I'm suspicious that your floor might be below the level of the pavement outside (judging from the lovely exterior photo :mrgreen: ), which will always lead to dampness inside. If this is the case then you need to look at the whole problem, not just an obvious part of it.

I found rotting wood in some of my walls - where it had a purpose (like attaching a corner beading strip) I replaced it with old joists but otherwise I filled the space with brick or stone using lime mortar (as we then replastered anyway). However, as suggested, in an older building take your time for everything if you can live with it - but hurry if you have actual water ingress (e.g. if fixing tiles/gutters/downpipes etc)!

Matthew

 

[TimHardusty]

Thanks for you comments and suggestions.

Yes, the cupboard is in the front wall of the house and it's floor is, indeed, just below pavement level (as is the sitting room the other side of the house). If I place my RH meter on the floor it is about 85% (17C) but if I raise it a few inches it drops markedly so I have already realised the floor is the main issue.

The tarmac of the pavement is laid right up to the front wall, and I have already found that the mortar fillet at the base of the wall (flaunching?) is not in brilliant condition. I am unsure whether to attempt to make a small channel at the base of the wall by cutting away the tarmac to improve drainage, or whether to simply re-do the fillet. I'll take a photo when I get home.

As for the cupboard, I am inclined to make a false floor with some boards on top of treated battens, probably not even screwing the battens to the ground - that should stop items at the bottom getting damp. And I will avoid modern plasterboard for the reasons stated, but I do like the sound of this to use instead, as then my poor plastering skills will not be taxed so much as it will just need a thin skim of lime plaster on top. And it is only a cupboard!

 

[Penners]

I'm suspicious that your floor might be below the level of the pavement outside, which will always lead to dampness inside.

Good point, Matthew, and well worth checking.

 

[TimHardusty]

Here is the base of the blocked-up doorway, showing the mortar in need of attention. You can see a steel "nut" relating to the gas pipe right at the junction of the pavement and the blocks. The mortar around that does seem to be OK and there's no puddling in the cupboard so don't think we have a leak as such.




This is further along the same wall (behind a planter) and a chunk has fallen off.



and here's the other side of the front door showing how close the tarmac is to the wall and the mortar pulling away.



Opinions on whether digging a channel (how deep? how wide? filled with anything) is worth it, or whether I should just repair the fillet (lime mortar I assume?).

The gutter downpipes do discharge on to the pavement and the one up the hill would benefit from a short extension to its outlet to make sure the water flows away from the house better, but it's not a disaster at the moment.

 

[Penners]

The gutter downpipes do discharge on to the pavement and the one up the hill would benefit from a short extension to its outlet to make sure the water flows away from the house better

Aha! That sounds like a very strong candidate for at least part of your problem.

 

[TimHardusty]

It won't help, for sure. Looking at the flow of water from the pipe when raining and it doesn't really look like it is running past the house...but the tarmac remains wetter nearer the house for a while longer so it is possibly also water running down the front wall...hence being concerned about the mortar fillet at the base of the wall.

The tarmac is abutting the fillet (i.e. the fillet extends below the tarmac).

The question remains as to whether I should repair the fillet, and seal the gap between the wall and tarmac, or whether a larger gap/trench would be beneficial with the fillet simply covering the lower stone joints? Or something different?

 

[Penners]

Studying your picture, it looks as though (if I'm understanding it correctly) the "floor" of the recess that was the old doorway is slightly below the pavement that abuts it. If this is the case, then I could imagine water pooling in this area. Not only would this encourage seepage through the bottom of the wall, but it might also be deleterious to the fillet of mortar if/when it freezes in winter.

I would try to ensure that water cannot flow into that old doorway recess, and put a fillet of sealant along the bottom of the wall, blending into the tarmac. Sealant isn't always a good plan because it stifles breathability, but in this case I can't see it having much of that effect.

The above is a fairly straightforward attempt at resolution. If it doesn't work, then we'll have think about more steps. Dealing with damp is invariably like this - try something, see if it works, if not move on to something else.

 

[TimHardusty]

Your interpretation is correct

The "floor" of the old entrance is a few inches below ground level, and is (but I'm in the process of removing it) painted in possibly a damp-resistance paint or maybe just emulsion, and had rush mats on it from the previous owner which were damp and mouldy. Not seen any signs of puddling, but it is definitely damp in there.

The whole ground floor of the house is just below pavement level but, for example, the parquet floor in the same room as the cupboard is not lifting or damp-feeling. Uneven, yes, but not damp and curly! But the sitting room at the other side of the house does appear to have suffered damp by the front wall which I am - for now - also attributing to the ground level difference and/or water penetration from run off down the wall behind the tarmac and.or gutter flow.

We have more or less decided to clean off all the paint on the stones and will then either improve the appearance with judicious use of lime mortar or I may get brave and try lime plastering it. In any even we will then simply lime wash it rather than lining it, so we can monitor damp more easily. I will fit a false floor to the cupboard that simply sits on the ground (on treated battens) so I can lift it out and see what's going on, and will ensure the lower cupboard door has ventilation (upper half has no door anyway).

I have no problem with the "try something, see if it works, then try something new" approach so will repair the obviously damaged parts of the mortar on the front wall and run a bead of silicone and see what transpires over the next year.

Many thanks for your advice and words of wisdom

 

[TimHardusty]

Forgot to add that the void where the old rotten timber was will be filled with local stone pieces lime mortared in...thankfully there are plenty of pieces of Portland stone on Portland

 

[Penners]

OK, Tim - do keep us in touch with progress.

 

[TimHardusty]

The whole ground floor of the house is just below pavement level but, for example, the parquet floor in the same room as the cupboard is not lifting or damp-feeling. Uneven, yes, but not damp and curly! But the sitting room at the other side of the house does appear to have suffered damp by the front wall which I am - for now - also attributing to the ground level difference and/or water penetration from run off down the wall behind the tarmac and.or gutter flow.

put a fillet of sealant along the bottom of the wall, blending into the tarmac. Sealant isn't always a good plan because it stifles breathability, but in this case I can't see it having much of that effect.

The above is a fairly straightforward attempt at resolution. If it doesn't work, then we'll have think about more steps.

Update. I put a bead of sealant as suggested. We have recently removed the carpet in the sitting room in readiness of having new laid. In the heavy rain of the last few days we can feel - almost see, actually - the bottom of the wall get damp after a while. I believe I will have to tackle this properly and dig out the ground in front to expose the wall completely.

My plan is to dig a trench to the bottom of the wall about 12" wide (being careful to avoid the gas, electricity and water services!) and use some Portland stone to make a retaining wall, perhaps proud of the pavement by a few inches and fill the trench with stone chippings. Other properties in the road already have this so there is a precedent.

A while back I asked Dorset Highways about doing this - with hindsight I probably shouldn't have drawn attention to it. They replied "...any works carried out on the footway outside of your property would need to carried out by a contractor holding the new road and street works act accreditation and appropriate licences approved...".

But if I simply got on and did this myself do you think I would actually get in to any serious trouble? Once done, surely whether it was done by an accredited contractor is a moot point?

 

[Flyfisher]

I'd say the scope for getting into trouble depends on who own the 12 inches of land outside your wall. If it belongs to the council then I can see nothing but trouble - and that's without considering the consequences of obstructing the footway, hitting and disrupting gas, water, electricity services or a member of the public tripping on your (unauthorised!) works and breaking their leg.

However, you mention that other properties in the road seems to have had similar works carried out (presumably for the same reasons), so I would suggest asking their owners about how they managed to do what you are proposing.

 

[TimHardusty]

CO (who has no interest in these works) mentioned in passing that the curtilage of the property probably extends to the middle of the road. Not what the land registry plans show though

Pavement is VERY wide (15 feet) and anyone walking where I plan to excavate would have to walk through our porch entrance first lol.

Look here:

and you'll see what I mean. Sitting room is on the right, although I will do the other room on the left too, at some point.

 

[TimHardusty]

At the risk of going OT on my own post (although it *was* the original reason for the topic lol...I have filled in the void left by the rotted timber frame using local stone collected every day when I walk the dog - lime mortared in of course

 

[Flyfisher]

The photo makes it much clearer and I agree that no one is likely to walk that close to the front of your house! Also, the porch detailing is interesting - I wonder if you could reasonably claim that all the ground from your wall extending out to the extent of the porch is actually your property? I don't suppose your title shows such a thing, although they are not always definitive in these cases.

Also, given that (I assume) no one has complained about the planters in front of your wall, I wonder if you could gradually introduce new planters until they cover the entire length of the wall then, if no one complains, you could gradually and stealthily excavate beneath them, finally removing the planters to reveal a nice metal grating.

As for curtilage, I don't think this is the same thing as ownership. Thus, the curtilage might extend to the middle of the road even if you don't own it, meaning that any alterations to it would require LBC - but I'm not entirely sure about that.