Green Building Forum - insulating over sleeper wall??? Wed, 10 Jun 2026 10:03:53 +0100 https://www.greenbuildingforum.co.uk/newforum/ Lussumo Vanilla 1.0.3 insulating over sleeper wall??? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16175&Focus=274579#Comment_274579 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16175&Focus=274579#Comment_274579 Wed, 17 Jul 2019 15:51:35 +0100 thebeacon
i currently have all the floor boards of my suspended wooden floor up. I am planning to insulate by attaching chicken wire under the joists and filling the gap between the joists with rock wool. My joists are 90mm deep. I will lay a Pro Clima Intello VLC over the joists before laying a 18mm OSB board layer and floorboards on top of that.

How should i go about insulating between the joists and sleeper walls? should i not run any insulation over the sleep wall as it will cause bridging?

Should i be sticking the Pro Clima Intello VLC to the wall all around the floor?


Thanks,]]> insulating over sleeper wall??? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16175&Focus=274580#Comment_274580 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16175&Focus=274580#Comment_274580 Wed, 17 Jul 2019 19:40:08 +0100 tony insulating over sleeper wall??? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16175&Focus=274581#Comment_274581 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16175&Focus=274581#Comment_274581 Wed, 17 Jul 2019 22:18:17 +0100 thebeacon Posted By: tonyIf you are in the UK then you are required to add more than 75mm of insulation.

I'm planning to create a hammock effect with the chicken wire to fill 200mm between the joists. Should i be insulating between the plate on the sleeper wall and the floor boards?]]> insulating over sleeper wall??? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16175&Focus=274583#Comment_274583 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16175&Focus=274583#Comment_274583 Thu, 18 Jul 2019 04:34:01 +0100 tony insulating over sleeper wall??? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16175&Focus=274589#Comment_274589 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16175&Focus=274589#Comment_274589 Thu, 18 Jul 2019 08:01:53 +0100 thebeacon Posted By: tonyYes but you will need ventilation holes through the sleeper walls. I would like to see insulation under the joists too.i like the idea of 200mm

I took out a number of bricks in the sleeper walls to allow for ventilation under the entire floor of the house. And currently placing more air bricks. Do you think its ok to run the insulation over the tops of the sleeper walls? If the insulation is touching the sleeper walls then would it not cause a bridge?]]> insulating over sleeper wall??? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16175&Focus=274590#Comment_274590 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16175&Focus=274590#Comment_274590 Thu, 18 Jul 2019 08:38:56 +0100 GreenPaddy
Might be wrong but I think you're asking about the fact that;

1. You will have only 90mm gap between floor boards and top of dwarf wall in which to insert insulation.

2. The 90mm joists rest on the dwarf walls, maybe on a wall plate too, so there won't be any insulation under that contact point.

3. Can insulation touch the dwarf wall.

My suggestions would be;

1. Fill the rectangular gap between wall top and floor board with a kingspan type insul. The wall is prob 100mm thick, so cut 90mm slices, and fit into the gap joist to joist. Bit of foam around for when it shrinks back, to keep in place.

2. Not much you can sensibly do about the contact point of joist onto wall head. It's only a small area, although repeated.

3. Once you've filled the gaps between floor boards and dwarf wall, go ahead and install the wool type insulation, packing it tight to the dwarf walls.

Definitely important that you're increasing through-wall ventilation.]]> insulating over sleeper wall??? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16175&Focus=274600#Comment_274600 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16175&Focus=274600#Comment_274600 Thu, 18 Jul 2019 16:09:14 +0100 tony insulating over sleeper wall??? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16175&Focus=274620#Comment_274620 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16175&Focus=274620#Comment_274620 Thu, 18 Jul 2019 22:29:55 +0100 thebeacon
that's what i have been trying to work out.

Posted By: GreenPaddyDefinitely important that you're increasing through-wall ventilation.


Yes as mentioned adding extra air bricks at the front and rear of the property and knocked out some in the sleeper walls. Where the hallway runs down the property and the doors open into the living and dining room, below the joists has not been bricked up, offering pretty substantial openings into the voids below the floor.]]>