Project: Insulate House - draughts

digital_biscuit

Hi All

Our hallway has been a very cold room of late so I thought I would have a look under the stairs to see whether anything in there was contributing to the problem.

After removing the junk and the carpets I was able to see daylight so I think I have found the source for the coldness, however I have no idea how to fix it.

Only half of the under-the-stairs is plastered, the rest just has breeze blocks (or whatever the building term for them is). There is therefore a quite large gap between them and the floorboards. I have airbricks in these position which is why it is so cold. These gaps are too wide (about 10-20mm in places) for sealant so I was wondering what would be the best approach to sorting this out? Any help would be amazing!

Thanks
Darren

llandyrnog

Hi, You can get a can of expanding foam from Builders Merchants or the DIY chains, Simply spray in the joints and leave a couple of hours to expand and cut off the excess. You could also extend the plastering down using the thickness of plaster to fill in the junction between the wall and floor. Finally lay an offcut of underlay or paper over the whole area and top off with an offcut of thick carpet.

willow_loulou

Hello, I have a similar problem behind my kitchen sink unit - what is the best *cheap* expanding foam please?

I was also going to use some sheets of polystyrene, is that a good idea or madness lol

digital_biscuit

I got some for £4 from screwfix, worked well, drying now will cut tomorrow and report back, thanks llandyrnog