Hi all,
This is likely to be the first of many posts.
I am an English Carpenter living and working in rural France (The Dordogne, South West)
I have subscribed to Fine Home Building magazine and the Website.
We allegedly speak the same language, but let me assure you some translation in Building terms will have to be translated (not as hard as translating French building terms) so please bear with me.
So down to Business
I am currently looking at buying an old French farmhouse that has serious damp issues.
Exterior walls here (in older properties) do not have a Damp proof membrane, and often the lack of proper foundations, they are built from stone with lime mortar. Read built straight on the ground, perhaps 2’ deep if you’re lucky.
Three of the four ground floor rooms have timber floors set on 3†by 9†oak joists. The joists sit on compacted soil.
The fourth room has a very small cellar that is about 8’ cube. With a crude sump pump arrangement. It is apparent that the house is suffering from serious damp ingress.
Joists have been attacked from a verity of wood boring insects and have fungal infections.
At present the majority of joists appear structurally sound.
I am looking for advice on how I may approach this problem.
My first thoughts are to lay internal drainage throughout the house leading to the cellar. Then improving the sump pump.
I would prefer to approach this work in stages, trying to cause as little disruption to the house as a whole.
If the joists are in a very poor condition I have considered laying a concrete pad where under floor conditions allow. Over the cellar a concrete I beam joist with block infill.
Also I plan to remove all interior plaster to 3’ maybe 4’ in the short term, to allow the wall to breath. At some point the exterior walls have been coated in a spray concrete render, which I guess is preventing moisture from transpiring (?) externally.
The roof is in very good condition with good quality galvanised guttering and down pipes fitted.
I hope this is a clear explanation of the problem I am facing.
I look forward to all your assistance in trying to resolve these damp issues.
Ian Howle
Replies
Stone walls.
Oak joists.
We really do speak a different language. I don't know those terms. Sorry.
Ron
I'm English so perhaps am able to form a mental picture of the building in question. I suggest you post some pics so the guys here can get a better understanding of the problems you are facing.
Most of the buildings in the USA simply aren't old enough to have been built in the way you describe, so there may not be too much help coming from this forum.
It sounds to me like you are going to have to do some excavating, to get the damp soil away from the fabricof the building
John
Welcome to Breaktime.
It would be good if you fill out any information on your profile so in future posts people know where you live and what you do.
Looks like you really have your hands full with this one, but you're in good company.
I think you're on the right track by starting with drainage issues. I would start with external drainage and move on to internal integrating the two. Make sure that all water flows away from the house of course. So much of dampness control depends upon where you're located, the climate, are you on higher ground, does water come in from surface or from under ground, or both? Do you have a lot of mature greenery around the house that perhaps should be cut back giving things a chance to air?
I put an addition on my own house a few years back with a basement living space, and it sits at the bottom of a swale with no where for surface water to go. I had to install drainage pipe around the foundation of the house bringing water into a pit with a sump to pump it on up and out.
Any wood contact with ground is not a good idea. Replace anything with concrete and build on up from there with membrane between masonry and wood.
I'll let the others pick it up from there.
You are very wise to do this project in stages being as methodical as you can. I don't know the extent of your experience with old homes but I will tell you that there are going to be times when it seem that all is folly with this and the overwhelm will be tremendous.
Do one thing at a time, finish it completely, then move on to the next. I have found this to be the healthiest approach psychologically on old home renovation.
S.W rural France eh? Sounds lovely. Have you read Peter Mayle's (sp? book 'A Year In Provence'?
Morning Ian and welcome..
I spose if I were you I'd be thinking of a central dehumidifying unit. My last house was in a town with lots of springs and moisture was also a big issue as water would come up right through the middle of basement floors on occasion. A lot of the houses around me had dehumidiying units installed.
PS...pictures would be nice : )
"What people will notice and remember is the broad brush of how how we act.We can aspire to reach our high ideals, or we can slide down the slippery slope towards the despicable." rjw
http://www.john-lennon.com/imagine-neilyoung.ra
http://WWW.CLIFFORDRENOVATIONS.COM
I guess I would look around and see what the rich people do when they build or renovate houses in your area. You can't be the only person thinking of doing it . You have been given lots of good information already here but I would think you would have to see what is available in your area which might or might not work for you. I would hate to think that after many decades of damp, drying it out might cause problems. Settling, shrinkage. Something to ponder after all you didn't say you owned it yet;)
roger
I don't suppose you could hire someone to jack it up and put a proper foundation under it? Probably very expensive. I was even wondering if you could dig and put concrete pads under the house and jack up from those and get some pressure treated beams to go under the joists. You say the joists are structurally sound, but you also stated that they had been attacked by insects and fungi. At any rate, you may want to replace them selectively, or sister new ones to them (or between them, might be better).
The previous comment to excavate and get the damp soil away from the fabric of the building would be ideal but how achievable is that in your situation? A dimpled gap-type plastic material on the outside of the foundation would go a long way to preventing moisture contact with the foundation but also creating a drainage plane so that hydrostatic pressure could not build to force water into the structure.
What more could be applied to the inside of the foundation walls to limit moisture release to the interior? Spray on sealants? Closed cell foam insulation board (would direct excess water downward to the drainage system you propose). Other than that, the walls must be able to breathe (permeate) moisture to the interior in order to dry.
Suggest you digest the tech resources at http://www.buildingscience.com
Beautiful country, spent time in central and southern France a few years ago. The wife and I plan to go back sometime.
Thanks 1 n all for your current suggestions.As to excavating the exterior walls, with the foundations being so shallow (2’) I feel this is a last resort option.My budget will not stretch to major works involving other contractors. I.e. underpinning (new foundations) I understand that I will not be able to stop the damp.The current owner has told me that the water enters from the lowest point of the cellar (basement) I believe the water table is high in this area.I am guessing that the damp that I have observed during my 2 visits could be condensation.During the last 2yrs that I have lived in France I have not seen damp problems this bad. Most people accept that a certain amount of damp is inevitable. Trying not to use cement and using lime is the preferred choice.My aim is to try and reduce the damp, by channelling it towards the sump.Please keep up all the good work and let me know how you would approach this problem.I will try and sort out some pics for those of you who are interested as and when I can.A plus tard toushowler
"My budget will not stretch to major works involving other contractors. I.e. underpinning (new foundations) "
One thing I've learned over the years of my mistakes is:
If you can't afford to do it right, don't do it. You are only adding costs in the form of a bandaid rather than addressing the problem headon.
The suggestions of using a local crew that has already seen and done these are great.
The local crew option does not realy exist in Rural France.The French live with the damp, or move to a new home letting valuable historic buildings colapse and disapear.
What is the nearest town?
Piegut
24360je fais ce que je veux
Piegut(pea goo)je fais ce que je veux
Is it on the river?
NoLots of LakesHave a look on Google Earthje fais ce que je veux
In your case I still think a dehumidifying unit would work well but only if you don't get real floods in there but what just came to mind...being its France.."FRENCH DRAINS"...duh...lol. You know what that is, right?
Thing is..if the water comes up through out the floor like it did in my previous house in another area of Cold "Spring" Harbor...then a French drain won't work really. Thats only good around the perimeters.
"What people will notice and remember is the broad brush of how how we act.We can aspire to reach our high ideals, or we can slide down the slippery slope towards the despicable." rjw
http://www.john-lennon.com/imagine-neilyoung.ra
http://WWW.CLIFFORDRENOVATIONS.COM
Hello Ian and welcome,
The insect and fungi can both be killed by spraying or fogging the infested areas.
"Also I plan to remove all interior plaster to 3’ maybe 4’ in the short term, to allow the wall to breath. At some point the exterior walls have been coated in a spray concrete render, which I guess is preventing moisture from transpiring (?) externally."
If the exterior surface doesn't allow for moisture to escape that would be of great concern to me. That kind of trapped moisture will kill a building quickly. Stripping the interior plaster is not a permanent solution. If the coating is truly impervious, your walls need ventilation full time.
This forum is a great place to kick ideas around in, but as someone else mentioned, I'd be searching out knowledgeable local help too. Hopefully they've seen both the problems AND the solutions many times already.
Best of luck, stay in touch, post pictures! ;-) buic
welcome Ian -
I don't think 2' deep foundations are a problem in your climate - does it get below freezing often? or stay below freezing for days?
does the house set on a hill such that a drain tile could be run from the basement to a lower point?
does the guttering and downpipes direct water away from the house so that the water cannot run to the basement?
have you removed the floor so you can repair the joist?
a complete cleaning and borax treatment would help preserve the joist - removing some of the compacted soil and replacing it with crushed stone would help keep the underfloor area dry -
bonne chance
DOUD
2 months solid, penatrating frosts last winterdrain tile is an optionguttering yes away from house yesI don't own the house yet so any floor removal is out of the question as yet.mercije fais ce que je veux
trench the exterior of the house..
parge the foundation..
WP the parging...
install drainage in the trenches...
turn the direct joist / earth contact areas into crawl spaces..
WP from the outside in and from bottom to top..
pictures would be nice..
Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming
WOW!!! What a Ride!
Forget the primal scream, just ROAR!!!
I am currently looking at buying an old French farmhouse
Out of curiosity, when was it built?
...3” by 9” oak joists. The joists sit on compacted soil.
Since they're not spanning, we'd probably call them "sleepers" over here. It doesn't seem like a great idea to have them laying in the dirt, does it? ;) Just sort of inviting moisture and insect penetration.
I don't know what the spacing or span are regarding the joists. If they were out of the dirt, would the sizing and spacing be adequate to meet load requirements? If not, perhaps you could modify what you have into a sort of post and pier arrangement. That is, run a secondary beam under (and perpendicular) to the joists to reduce the span. A number of concrete footings and pier blocks would be required to support this new beam.
Edited 6/10/2007 12:43 am ET by Ragnar17
I have very limited experience with crawl spaces, since all the houses where I live are built with basements.
For those here who have more experience with crawl spaces:
(1) Isn't it common practice to put down vapor barriers to limit the amount of water vapor migrating out of the soil?
(2) Isn't it also common practice to put a number of screened vents in the foundation walls?
It sounds like Ian has neither of these.
Edited 6/10/2007 12:47 am ET by Ragnar17
The vast majority of houses here in Western Washington are built over crawlspaces and yes, we use 6 mil poly vapor barrier on the ground, ventilate the crawlspace and insulate the floor to R-30.Mild climate, seldom gets into the 80s or below 30 degrees.Huck said it first. I just agreed with him.
Thanks for the post, Jim.
It's not clear to me whether the OP is experiencing moisture problems related to humidity issues or outright water flow into the crawl space.
Would water flow impact your decision to put in a vapor barrier?
To be honest, I have read and thought about, and changed my mind so many times on crawlspace issues that I do what code demands, and trust that enough people smarter than me are making these decisions about how to best weatherproof a house in our climate. The only reason I even said anything was because you specifically asked.
It took me a couple years to get my head wrapped around "relative humidity" issues. No way I feel comfortable giving practical advice about what someone should or shouldn't do in any given situation moisture wise.
I WILL say though, that intuitively I agree with the posters who are saying combat the water intrusion issues BEFORE they get into the building. Of course, that's difficult to envision in a case like Andy Clifford describes with springs under a building.
Interesting discussion, for sure. These are the type discussions I often find myself coming back to day after day to see what else has been said. Most of the time it's stuff I am pretty ignorant about. Huck said it first. I just agreed with him.
Concerning vapor barriers in crawl space--if there is actually water flowing under the house, like in springtime after heavy rains, the VB may do more harm than good--if it even stays in place. Chaneling water away from under the house may be his best bet.
Yeah, I wondered about the plastic if there were ground water problems. I don't know for sure what that would do. Also, I'm not sure what the source of the OP's water problems really are. It could, in fact, be a combination of both water entry and vapor coming from the ground.
If there's water entry, then it sounds like he should put some trench drains around the perimeter as a bare minimum.
I used to have a GF with a "renovated" cider press house in Normandy, so I have some feeling for your situation. You're way ahead of the game if you really have a new roof....I spent a lot of time hunting down authentic clay interlocking roof tile (even found some in glass for a skylight-that was slick)...
Not sure why you'd even think of stripping the plaster....but maybe I'm missing something by assuming that the walls are stone....if they are, even with the spayed on whatever-it-is outside I wouldn't be stripping the plaster....
A lot depends on the quality of the stone foundation...laid tight with minimal mortar, or just rubble in a trench?
It's hard to give advice from here, but fumigation, good landscaping/gutter drainage, oak sleepers off the dirt, and improved sump-pump might go a long way towards a solution.
The older I get the less I like basements, unless the local conditions are just about perfect. When you need the sump pump most tends to also be when the power goes out.....
Sure there's no "local crew" around?
Good luck Chippy ;-)
When you say "fungal issues", please tell me you don't have Haus Schwamm!
If you do DO NOT purchase the house. That stuff sends tendrils thru anything organic & you may as well tear the thing down & start over.
I don't know if there is an English translation for Haus Schwamm & I KNOW we don't have it in the US (architect sister ran into it in Germany...she says it looks like the stuff coming up the lighthouse stairs in a Dr Who episode).
Traversed intense Cicadozones on I290 thru OakPark IL, North Ave in Elmhurst IL & Irving Park Rd thru forest preserves in Schiller Park IL. Cicadas flying all over with buzzing enough to drown out the radio!
No its nothing like that.Some fungil growth like mushrooms, but not!Do love "Doctor Who" though.Guess that must have been one of the old shows.We used to hide behind the couch, when I watched it as a boy.je fais ce que je veux
LOL Tom Baker episode. We especially loved the Daleks
"EGGS...TERMINATE!!""EGGS...TERMINATE!!"Traversed intense Cicadozones on I290 thru OakPark IL, North Ave in Elmhurst IL & Irving Park Rd thru forest preserves in Schiller Park IL. Cicadas flying all over with buzzing enough to drown out the radio!
Do you remember "The Green DEATH"b4 Tom Bakerje fais ce que je veux