OK...the garage conversion is actually happening. All of the external
building work is complete. :-)
I've now got to do the floor. I was going to lay 50x125 wooden beams at
400crs, and infill with Celotex XR3120. But when the guy from Building
Control came to inspect the external building works, I spoke to him and he
suggested to me that it would actually be far easier for me, if I simply
laid the Celotex wall-to-wall (without the timbers), and then put a
damp-proof membrane over the top, then topped it all with 22.5mm T&G
chipboard, which is glued together. He said that if done this way, the floor
will move a micron in it's lifetime.
So that's what I'm now doing - I'm not going to argue, especially if it's
making my life easier. However, I have a wee problemette...
The Celotex is 2400mm x 1200mm. The garage is 4900mm x 2480mm internally.
Effectively, having laid four slabs of Celotex, I would have 100mm gap at
the end, and 80mm gap at the side. So I need a fifth slab of Celotex. I'm no
expert, but I do wonder whether cutting what would be thin slivers of
Celotex (compared to the 2400x1200 slabs), and slotting them in at the sides
is really the way to go. Or whether I should aim for less complete slabs,
but overall, bigger slabs wherever used.
I hope that makes sense? Does anyone have any idea? I will then also have a
similar problem with the T&G floorboard, but with that, I can see definite
benefits to cutting them in half, as then I can put the flat sides of the
boarding next to the wall (well, 6-10mm away).
There's no need to apply it like silly string. Cured foam cut flush and
covered with 3" foil tape is ideal for the job. The insulation will be
bonded together to form a single sheet so will be better than loose with
fillers. If the BCO was ever to notice he would not object.
BBC3, ITV2/3/4, channels going to the DOGs
If I could dryline the walls before the council inspected, then it would be
OK. ;-) But they want to inspect the floor insulation & damp proofing before
I can continue. I agree about the expanding foam. Sounds a bit messy. I've
ordered 5 Celotex slabs. I will just have to puzzle out the best way to fit
No problem the building inspector and gaps as they won' be part of the
floor, they will be under the walls. Try speaking to him about it. If
he insists on full width insulation then simply cut 80mm and 100mm
Celotex strips it's dead easy with a saw, I have cut strips as narrow
as 12mm in my loft space.
Thanks. I've decided to do just that (cut strips), but fred's post prompted
me to wonder if the thin strips might be better in the middle. So I'm
actually going to lay the four complete slabs in each corner, then complete
the centre of each axis with cuts of 2400x80, 2400x80, 1280x100 and 1200x100
from the fifth slab.
I want to go wall-to-wall to be honest, as I did read somewhere (Knauf site
I think), that bottom of wall gaps are one of the problem areas for
insulation. And I've already ordered the fifth slab of Celotex! ;-)
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