single skin blockwork insulation

Discussion in 'Eco Talk' started by georgemcintyre, Mar 27, 2018.

  1. Attached Files:

  2. Jord86

    Jord86 Well-Known Member

    What's the covering on the outside of the blocks?
  3. its a johnstones system render(stormshield) similiar to stow etc
  4. Jord86

    Jord86 Well-Known Member

    Ok, if you didn't have a form of render in place I would have suggested a stud wall inside with a cavity, you could still do it out of 2x2 and fill in between the studs if you wanted with kingspan and board with foilback plasterboard. If not, dot and dab insulated plasterboard onto the thermalites and add a couple of mechanical fixings too.
    Deleted member 33931 likes this.
  5. hi jord and thanks.

    i was thinking 2x1 screwed to the walls backed with dpm, then screwing insulated plasterboard over batons?
  6. Jord86

    Jord86 Well-Known Member

    You can do, I suggested dot and dab on the basis that you may not have a hammer drill and drill driver, and it's quicker. If you're happy to batten it then go for it.
  7. got all the gear, just no idea, thanks jord
  8. Bob Rathbone

    Bob Rathbone Well-Known Member

    If you fix the battens directly to the wall, they will get damp from moisture penetration. Either fit a DPC between the batten and the wall or space it off with brackets or plastic spaces. Use tannelised timber in either case.
  9. You have what is seemingly an excellent outer covering, so no real risk of penetrating damp.

    What are these blocks - normal concrete or are they thermalite? Anyhoo, the only difference that would make is the thickness of insulation you might want to go for - slightly thicker for concrete. (And that Thermalite is very absorbent, so you'd have to allow for this when bonding to it.)

    Ok, this is what I would do. If I wanted to be sure to be sure of zero water penetration, I'd get a couple of tubs of cementous tanking slurry and brush/roller it on, paying special attention to the bottom row and where it joins the floor. Then I'd D&B insulated plasterboard on to that surface. I'd probably choose 45mm insulation layered board.

    Insulted p'board acts as a vapour barrier too, so extra protection (check the specs of each type). Really, you'd be nuts - wantonly masochistic - to start battening this out, what with multiple screws being driven in to that wall, the extra internal space taken up and the extra cost. I mean, why would you?

    Thickness of insul board to use? Whatever you add will make a huge difference, but say around 45mm insulation is probably the best compromise between space, cost and effect. Go thicker than this and the additional benefits are marginal.

    Easy to drill and bolt through this layer in to the wall for any fixings you may require for shelving, etc.

    And as said above, add a few mechanical fixings too - say 3 or 4 per board - as this is recommended in case of fire and the walls start peeling off! That's your call - they aren't required for fixing strength as D&D is very sticky.

    Take care around the window and door openings - make sure you keep the insulating layer continuous and unbroken. Not a bad idea to have a tube of spray foam too, and run a teeny bead down each joining edge just before fitting.

    On that note, perhaps there are better D&D adhesives to use than dry-wall adhesive too?

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