Damp house and MFC / MDF kitchen units.

[pren]

Morning all.

Just been to visit some clients who want a kitchen made by me. They're in the process of totally renovating a 200+ yr old farmhouse. It's been stood empty for the last 3yrs and has been in a very bad state of repair for the last 10yrs.

Issues with leaking roofs and rising damp in the solid stone walls have meant that the whole building is full of damp. The causes of the damp have been fixed (new roof, new floor with DPM, weather proof ext walls with lime render inside) but it's going to take a long time to fully dry out.

The clients are looking to move in in June and are worried that the MFC or veneered MDF kitchen cabinets I was proposing won't stand up to the damp conditions as the house dries out.

I'm not sure how damp the house will be, especially if they're happy to live there, but they've been advised by a 'builder friend' that MFC units will turn to wet wheetabix inside of a year.

Does anyone know if this is an accurate prediction? I was going to buy the units from here. All the edges will be sealed and they will be stood up on plastic legs.

If they're going to be made by myself, the clients have asked for them to be made from Pine (timberboard). Their thinking being that solid wood boards would be less suceptable to moisture. I'm pretty sure this is a bad idea as surely man made boards would be much more stable in high moisture conditions?

If I were to use Oak or pine veneered MDF, is the MDF core likely to be moisture resistant or is this a different product?

The house is on the side of a mountain in south wales. The clients are really looking for an 'honest' traditional kitchen ie: no 'modern materials' but they're happy to compromise as long as the materials are suitable. I'm happy enough using pine timberboard to make the units as long as they're not going to warp all over the place inside of a month!

As ever, all help greatfully recieved!

 

[kasandrich]

If it is wet enough to be a problem with sealed edges, then it won't be habitable surely?

 

[PAC1]

Why not take a piece of MDF or even the veneered board you intend to use and leave it on a brick or something in their kitchen for a few weeks and see what happens. Maybe best not to do this immediately after the floor is laid but after a three or four weeks it should be fairly dry

 

[Jake]

There are various off-cuts of MFC on my 'patio-to-be', where I was cutting up cabinets and so on this summer. [Yes, I must tidy up, sigh]. They've been there all autumn and winter, raw cut edges exposed, on the sodden ground, through a few freeze thaw cycles to boot. No sign of any deterioration yet, it hasn't swollen up, it's as hard as it was. That's a good quality Egger MFC.

There's no guarantee it will be OK, but the chipboard=weetabix thing is clearly very overblown (at least with quality stuff).

 

[MikeG.]

Careful with that Jake! Chipboard is very different to a MR MDF, and really does turn into gloop rapidly. Go and have a look under a kitchen sink where even a bit of condensation on the mains supply pipe usually turns the unit into pulp, as any plumber will tell you.

-

My general advice in these circumstances would be to make as much of the kitchen carcass as possible out of solid timber, and to leave the plinth off and the doors off for as long as the client will tolerate. I would certainly look to leave the plinth off for at least 6 months. This will enable the circulation of at least a little air, and will help prevent the growth of mould.

If the client will tolerate it, I would even suggest having a cheap carcass installed temporarily, without doors, for 6 months or a year, with a curtain over the front if needs must, then fit the proper kitchen when everything is properly dry.

Mike

 

[Jake]

Careful with that Jake! Chipboard is very different to a MR MDF, and really does turn into gloop rapidly. Go and have a look under a kitchen sink where even a bit of condensation on the mains supply pipe usually turns the unit into pulp, as any plumber will tell you.

The stuff lying around on my patio is MFC, not MR-MDF. I think I was quite careful enough with the way I couched my observation!

 

[MikeG.]

Ooops, sorry.......I should visit Specsavers! I wonder if being outside your scraps dry off in the sun and wind, whereas inside, it really does turn to pulp in a matter of months.

Mike

 

[Jake]

Did you mention sun? Your weather must have been nicer than ours lately... Possibly, I can't see that being the reason given that it's had six months out there and it has been so soggy this winter.

I think I remember seeing a bit which I'd chucked in a bucket - I'll have to check that and see if that's gone funny in constant immersion.

It might well be different qualities of MFC. The Egger stuff is reputed to be one of the best. It is certainly a lot more dense and solid than something like Contiboard.

Actually, I have some contiboard which I used for a mock-up of something, as a minor extension to my accidental experiment I might stick that some of that out there and see how fast that goes to mush. My money says a lot quicker!

 

[MikeG.]

....and that will be the point, Jake. These carcasses are made of the cheapest possible stuff, not your posh version.

Mike

 

[Jake]

It's not posh as in expensive, just supposedly better quality than some of the competitors. My supplier said "it doesn't matter what board you choose, with the volume we buy it makes no real difference to the price".

Those carcasses don't look all that corner-cut. 18mm not 16mm, full height 18mm* backs.

(*I know a very expensive "box-maker" who wouldn't stretch to that, naming no names).

 

[would not]

I put my mums kitchen in her old house which had rubble walls etc - lime plaster and all that jazz. I put batons on the wall with DPM between the wall and batons and sat the carcasses off the wall a little more than usual I also didn't put a kick board/plinth on so as to make sure air would get around the back. You may have a problem if you seal it all up especially with MDF, they should be taking moisture readings to see what the walls are like. Lime plaster etc lets the walls breath so sealing them with kitchen cupboards is not going to help.
The units I put in my mothers were the 18mm chipboard type and were okay and damp was not a problem, you'll only have a problem if the backs are sealed up and no air gets to them.

 

[pren]

Hi, thanks for all the comments! :-D

I've never experienced dampness in any of the houses I've lived in so i don't really know just how wet it can be. The floor slab was poured 3 weeks ago at around the same time that the walls were weatherproofed. The last of the new windows was going in when I visited the other day. I'm not sure when the lime render is going on but I think that takes a while to dry so will add to the moisture content of the house?

I don't think there's going to be any insulation on the solid walls but there will be a range for heating and cooking in the kitchen as well as a log fire in the lounge (just off the kitchen).

The clients are looking to be in by July, so assuming there's ventilation and the fires are lit regularly, is it possible that the house could be drier in 5 months or so? The footprint of the house is about 5m x 10m ish with 3 bedrooms upstairs.

I think the idea of leaving ventilation space around the units is a good one. Would it also be an idea to stop the back panels of the units short of the worktop height? Or would this just encourage damp air into them?

With the wall units, I was going to ask the clients to have a strip of ply fixed to the wall before the render is applied so as to give me something to fix the units to. This could also help stand the units off from the wall by a few mill to alow for ventilation. Is this a good idea?

If I were to use MFC for the units, is there any particular rating to look out for on the quality of the sheets?

If I were to use laminated pine boards, would a couple of coats of polyurathane varnish on all faces/edges be enough to protect them from the worst of the moisture?

Apologies for all the questions. I was quite happy with this project until the damp spanner was thrown into the works. :roll: :lol:

 

[would not]

I bet it's like a swimming pool in there. I take it there's no heating on yet? Plus new windows will keep all the moisture in, Floors can take months to dry unless special cements are used, has it yet to have a screed on as well?
The room will need plenty of ventilation to get walls/floor to dry but I bet they don't want to have the windows open right now. Dehumidifiers are ok but tend to suck moisture from the surface (a few inches) giving you the impression everything's nice and dry only for the surface to become damp again. If a dehumidifier is used make sure it's turned off for a day a two then test for damp again.

You'll find customers always want it done NOW, even if you explain about damp etc they just won't wait, the word wait and waiting are just not words customers use until it's time to pay.
If you feel you are being rushed to put it in earlier than you'd like I'd make sure they know you can't be held responsible for things growing due to damp.

 

[OldWood]

Some 20 years ago I was out of work and was helping my cabinet maker kid brother install himself into an old stone barn on the moors near Lanark.

The back wall had had no guttering for some time and was absolutely sodden. We were astounded how quickly that dried out after replacing the guttering and he was able to produce good product that didn't shrink when installed in quite short time.

On the basis that this is going to be liveable in and every effort made to make it dry warm and snug, then I can't see a problem. There will be major cost advantages to the purchaser if MDF, etc is used, so he should be offered the options with caveats to cover your back !

Rob