Draught From Behind Kitchen Units

[fouxdafafa]

Hi,

I'm in the process of finding, and hopefully fixing, all the draughts in my very draughty house. I've always suspected that there's something amiss behind the kitchen units because the crockery we keep in them is always extremely cold. I've taken the plinth off the sink unit and I've found that there's a gap between the bottom of the plasterboard and the floor i.e. the plasterborad doesn't meet the floor, and I'm pretty sure that's part of the problem. Not quite sure what kind of construction the walls are, but I think they're of the kind where it's brick outside, breeze block inside with plasterboard (dot and dab?). I haven't taken all the plinths off but I suspect that this gap is all the way around the kitchen - at least on the outside walls. Any suggestions as to how I could fill the gap between the plasterboard and the floor? I'm pretty sure the coldness in my house is caused by draughts behind the plasterboard escaping at various points.

[Burnerman]

Obviosly you have a suspended timber floor, and as there is a gale blowing around down there it shows that the air bricks are working perfectly......it keeps things nice and dry.
You can fill the gap with strips of timber if you can get in, or expanding foam if you can't - so long as it cant be seen!
In normal construction, the skirting boards plug this gap - but gaps often appear due to natural settling and shrinkage, etc.
John

[fouxdafafa]

Thanks for that. There is no skirting board behind the kitchen units, and it's going to be hard to get to, so I may have my first experience of expanding foam.

[Burnerman]

It'll probably be your last, fella as the ruddy stuff goes everywhere and never flows like the adverts say.....thoroughly dampen the area you intend to fill, don't overdo the spray, always wear gloves because the stuff stays on your skin for months and buy a small can. You'll be delighted to throw it in the bin afterwards.
Good product though!
John

[fouxdafafa]

Oh, b*gger. That doesn't sound too good. Ideally, I'd like to fix a strip of skirting board, but I fear it's going to be almost impossible to get to from underneath the units. It's going to be hard enough to use the foam - I haven't even checked if I can reach yet. Any other bright ideas?

[foxhole]

Just to make it more difficult the foam cans normally have to be used inverted or you just empty the can of pressure and not foam. lighter fuel will disolve the foam while still wet, any large spillage should be left, as it will come away in one lump when cured.

[Mickymoody]

Maybe where the larger kitchen sink exit, had a chunk of brick fall out, or even where a boiler exit, where large chunks of bricks have been knocked out, the cold weather has got in, and cracked stuff open, so you are getting a vacuum of air in the room, ie like when you leave all the doors open in the house, and a door will slam, due to the pressure differentation?

Has your area had really bad snow so far? Last year, due to being open at the back of the house, really has taken a toll on the woodwork.

[StephenW]

I think I would try a strip of wood like a skirting board - it doesn't have to be neat. Maybe put some draught excluder strip along the bottom (floor) edge and then glue to wood (gripfill?) to the plasterboard. At least the gap will be smaller and you might be able to finish it off with some mastic or caulke.

[bathjobby]

I had the same problem. I used manageable strips of plaster board (skirting size depth). I cut to a size that I could manage and dry fitted it in front of the gap so that I knew I could get it in there. Then dampened the board and the gap (so foam takes to it), sprayed foam along the length of the board and QUICKLY put it into position. The foam not only acted as the adhesive but also got pushed into the gap behind the new strip of board. The difference was very noticeable and I have a solid floor not boards with gales underneath, so it was purely the cold drop from behind my dot and dab plasterboard.
n.b. best to get all the plasterboard strip ready first, dampen the whole gap and all the boards. Then do the spray and fit in one operation then get rid of spray can and gloves used - horrible stuff but effective.

[ianb1469]

This sounds like a great idea for sealing up drafts where you cannot reach.

bathjobby wrote:

I had the same problem. I used manageable strips of plaster board (skirting size depth). I cut to a size that I could manage and dry fitted it in front of the gap so that I knew I could get it in there. Then dampened the board and the gap (so foam takes to it), sprayed foam along the length of the board and QUICKLY put it into position. The foam not only acted as the adhesive but also got pushed into the gap behind the new strip of board. The difference was very noticeable and I have a solid floor not boards with gales underneath, so it was purely the cold drop from behind my dot and dab plasterboard. n.b. best to get all the plasterboard strip ready first, dampen the whole gap and all the boards. Then do the spray and fit in one operation then get rid of spray can and gloves used - horrible stuff but effective.

We have a similar problem, which I had largely fixed with expanding foam into the gap between the floor and plasterboard. I had hoped to make sure that plenty of foam got between the floor and the breeze block wall.

The problem with this construction is that since the suspended floor is not sealed to the breeze-blocks, the outside-temperature draft from below the floor just blows behind the dot and dab plasterboard. What's the point of cavity wall insulation if you have a draft behind the plasterboard!

[LooPrEvil]

A simple remedy: use strips from a roll of loft insulation and plug the gaps. B&Q have recently been selling rolls for £3.

[Lusi83]

I had the same problem - pulled the plinths off and stuffed loft insulation in the floor/wall gap - also round my waste exit/water inlet pipes under the unit under the sink'
Was your house built in the late 60s or 70s...they had a habit of sticking air bricks all up the wall in the kitchen (think the idea was it was a cooler pantry area...)

We had 2 (as well as the standard under floor one) - used to be hidden behind a cupboard- when I had the kitchen done stuffed a plastic bag in and then filled with expanding foam...my neighbours have blocked theirs off too...
My parent's first house was the same and they did similar as did their neighbours...never heard of anyone having a problem...although someone could tell me it was hideous mistake and it takes more than 30 years to develop the problem...
(Obviously don't do the under floor ones...)