Cottage Renovation - Damp Problems

SparkeyByrne

Hello, I'm about to start renovating an old cottage with damp problems. No apparent DPC in either walls or floor. Retro fit quite a big job so was planning on dry-lining whole house with 50mm insulation and dpc backed wall battens. Problem I see though is that the damp will still be there behind the boards. Is there a method to ventilate this out? Do I put in a vapour barrier on warm side of insulation as normal? I would appreciate any advice you might have. I'm handy enough and can do most of the work myself but would like to get this bit right from the get-go. I was considering digging out old slab entirely and laying new floor complete with DPM and insulation. Big job but do-able. Would this just drive more moisture over to and up the walls though without a suitable DPC laid there?

Confused!!!

ircoha

IMO, unless there are very compelling reasons not to I would flatten and rebuild from new.

No6

ircoha wrote: »

IMO, unless there are very compelling reasons not to I would flatten and rebuild from new.

A rather sensitive approach I think, firstly where are the damp problems, if in the floors dig out and fit a radon/dpm, what are the walls made of, can you either inject a silicone dampproof course or use an electro osmotic system?

SparkeyByrne

Thanks for the quick replies folks - although I'll hold off on knocking the building for the moment!

Walls are stone with a sand/cement render so not overly confident with any of the injection methods. Osmotic System might be an option though - although there are a lot of negative posts out there for this method also. The science sounds reasonable but I've yet to hear/read about a successful installation.

It's hard to say exactly where the damp is coming from. (waiting on a moisture meter on ebay at the moment!) The roof and guttering seems sound and as the damp appears quite high on the walls (close to ceiling in places) I can only summise that it's coming through the wall from outside as well as rising from below. I wouldn't consider it "extreme" dampness as it's only causing minor staining but obviously needs attention.

Knocking the damn thing might be an option after all....!!!!

No6

SparkeyByrne wrote: »

Thanks for the quick replies folks - although I'll hold off on knocking the building for the moment!

Walls are stone with a sand/cement render so not overly confident with any of the injection methods. Osmotic System might be an option though - although there are a lot of negative posts out there for this method also. The science sounds reasonable but I've yet to hear/read about a successful installation.

It's hard to say exactly where the damp is coming from. (waiting on a moisture meter on ebay at the moment!) The roof and guttering seems sound and as the damp appears quite high on the walls (close to ceiling in places) I can only summise that it's coming through the wall from outside as well as rising from below. I wouldn't consider it "extreme" dampness as it's only causing minor staining but obviously needs attention.

Knocking the damn thing might be an option after all....!!!!

If its high up & close to the ceiling it is most likely coming down from the roof. I assume there's no felt on the roof, it only take a tiny pinhole to let water through. If the roof is reasonably good you could spray under the slates with polyeurthane insulation which while its not guarnteed should keep the mopisture out, you could of course also replace the slates.

I have used electro osmotic systems a number of times including in my own house (also dug out the floor) and I dont have any problems after 6 years. Its hard to tell without seeing it. Get your Architect/Engineer to have a look and see what they think, every refurb has its own problems & solutions!!

Don't listen to the knockers I had a lady with a cottage who wanted the roof off and it made into a much bigger story & half house, no problem planning got except all teh contractors wanted to knock it down, much cheaper to build from scratch they siad except it wasnt only about 60K over the poor womans budget and her looking at me all the time like a drowning fish ( you know the helpless mouth open where's the water kind of thing!!) Eventually through sheer bloody minded persistance (on my part) she found a contractor who priced for the work as designed and lo and behold it came in bang on her budget so stick at it

Slig

If its a stone building then sand and cement plaster wont work, its too rigid and it doesnt allow the building to breath. check your roof as already posted, but if it does turn out to be the walls then it might be worthwhile looking at lime plastering the outside walls. Dry lining isnt a solution its just a method of hiding the problem. If the damp is at ground level check the diference of level between the inside and outside, if outside is higher then a french drain should be constructed around the house. Digging up the floor and fiting a dpm wont stop the damp in the walls.
I also disagree with knocking and rebuilding. You will never get the same atmosphere in a new flawless plastered room as you get with thick stone walls and the large window boards.

SparkeyByrne

Thanks Folks for all the advice. Will check the roof out in more detail and see if I have anywhere letting in water. Good to hear a positive report on the Osmotic System. As a matter of interest what system did you use and did you source it in Ireland? Did you install yourself? I've been looking on line for suppliers but as I know very little about the system it's hard to be objective.

I'm thinking that if I rule out the roof, install Osmotic System and pull out the slab I should be ok. Oh forget about the render! I spoke to a mate today and he reckons that the walls are not stone and are actually block. I've yet to knock through to investigate but will do so now to be sure. Will report back.

Keep the info flowing in!!!

SparkeyByrne

Hi Folks,

Just thought I'd post a photo of the house and see if anyone has any opinions as to its construction - bit of a long shot but sure you never know!!!

Thanks again!!!Lacken 018.jpg

Slig

The extension out the back is probably blockwork but the cottage looks very like a trad 3 room cottage and probably stone

PS if its only the extension thats damp then I'd reccomend knock that and rebuild, its probably only cavity block with no DPCs or insulation and that roof looks like its had it, flat roofs of that sort only have a lifespan of 15 to 20 years max

SparkeyByrne

Thanks for that Slig. Thinking along those lines now myself. I reckon (planning dependent) that knocking the back ext and rebuilding would be the best bet all round. I should be ok on the planning front as long as I dont go over 40Sqm. I wouldn't be altering the front roof profile either but probably worth dropping into a planning clinic in the council offices just to be sure.

Cheers for the advice.

RKQ

I agree with Slig.
Looks like a nice project, lots of character.
(Santa won't have a problem, lots of choice!)

Ground floor might be close to finished floor level. Worth considering reducing the external ground level and digging a perimeter french drain.

Good luck.

No6

SparkeyByrne wrote: »

Thanks for that Slig. Thinking along those lines now myself. I reckon (planning dependent) that knocking the back ext and rebuilding would be the best bet all round. I should be ok on the planning front as long as I dont go over 40Sqm. I wouldn't be altering the front roof profile either but probably worth dropping into a planning clinic in the council offices just to be sure.

Cheers for the advice.

Sparkey just watch out that you dont exceed 40 msq for all extensions (including those already built if you dont knock them down!!)

caspermccormack

you'd have plenty of dry fill on that concrete roof for the new build, never mind the walls:D

gsxr1

I was involved in an old stone barn conversion before the hols this year.

Turned into a two story home.

We dug out the old concrete floor . I dont know how they made concrete back then but it was as hard as any I came across. Me and 2 other lads with big breakers and wheel barrows.

Hard Work . does not take long to fill a few skips with rubble.

then.

4 inches of 804 wacked .

DPM turned right up onto the existing walls

4" of kingspan

4" of 25n 10 .


Used the Osmotic System . some other lad installed it.

SparkeyByrne

Thanks folks for all the posts. I'm definitely coming around to the idea of dropping the rear extension and extending out from the old building. 40Sq m would be plenty as the original cottage is'nt that small to begin with.

I agree with Casper - plenty of dry fill material available after dropping the ext! The thing is solid concrete - including the roof! Nothing like recycling to save a bit of money.

Thanks again.

davidoco

An idea for you if you demolish that rear extension.



Also you should consider getting up on that roof and replacing that missing slate ASAP.

SparkeyByrne

Thanks for that David. Clever way of upping the square footage. I'm not sure it would work here as the site mightn't allow it - you would probably manage to build it but would be left with very little room around the house - you can't really make it out from the photo I posted.

Definitely food for thought though.

Thanks

Rosa Lee

Hi Sparkey,

I have a cottage that looks exactely like the one you have. It is 105 years old and I do not know where to start. Would you recommend letting one contractor take the whole job on or do it bit by bit?

Everything needs to be redone, rewiring, new roof, demolish old extention, new windows, new bathroom and of course damp proofing.

Do you have any idea how much this would cost? or is rebuilding a better option?

Thanks for any pointers you may have!

R

SparkeyByrne

Hi Rosa,

Sorry for delay in getting back to you as I was away - up in Donegal for the mid term in the new cottage we actually bought instead!!! We almost went for the old one in the earlier thread but the realisation of just how much work was required frightened the bejesus out of my wife (and me if I'm honest!)

We opted for a new build in the end, nowhere near the character but a lot easier. We are a five min walk to beach though which is a bonus. To be honest we took advantage in the downturn in economy and realised that we actually could afford a new build after all. The renovation had been more out of necessity rather than any particular gra we had for the project. I wish you luck though - it's not for the faint hearted!!!

All the best.

Mark

dazflan1

SparkeyByrne wrote: »

Hello, I'm about to start renovating an old cottage with damp problems. No apparent DPC in either walls or floor. Retro fit quite a big job so was planning on dry-lining whole house with 50mm insulation and dpc backed wall battens. Problem I see though is that the damp will still be there behind the boards. Is there a method to ventilate this out? Do I put in a vapour barrier on warm side of insulation as normal? I would appreciate any advice you might have. I'm handy enough and can do most of the work myself but would like to get this bit right from the get-go. I was considering digging out old slab entirely and laying new floor complete with DPM and insulation. Big job but do-able. Would this just drive more moisture over to and up the walls though without a suitable DPC laid there?

Confused!!!

I agree with what "No6" says. Also as simple as it sounds , with it being solid stone walls, maybe repointing the walls could help. I had a similar problem of damp in the upstairs bedrooms. The damp was comining in threw the chimney so we relined it and that worked for us.. best of luck with your renovation

dazflan1

SparkeyByrne wrote: »

Hi Folks,

Just thought I'd post a photo of the house and see if anyone has any opinions as to its construction - bit of a long shot but sure you never know!!!

Thanks again!!!Lacken 018.jpg

the extensions at the back probably is block, but by looking at the photo the older front part of the house maybe stone.