Garage to workshop conversion: cladding the ceiling

[Bert Coules]

It would add a fair bit to the weight, though, surely? And plasterboard would be heavy enough to begin with.

Bert

[NT]

:

One time I used expanding foam I did just that. I used a stack of books to jam the piece firmly in place. Next day I saw the foam had exerted huge force and that bit of ceiling was a lot lower until i found a round tuit one day

NT

[NT]

Wouldnt add more than 100 grams a board, once dry.

NT

[Adam Aglionby]

Known by the Australians as Coro, here as Correx ,Coroplast , sometimes as twin wall corrugated plastic but that usually brings up clear polycarbonate,PC, roofing sheet.

Its a great material for making and lining, flutes seem to make a good insulator, think of it as a waterproof corrugated cardboard, one major downside though, its polypropylene,PP, which is resistant to gluing by just about anything, hot melt will hold it but has no shear strength, mechanical fixings are a better bet, plastic redidrivers work really well ;-) as well as folding it on itself:

is common as flooring protection sheet, 4mm is common sign thickness and self rigid in a 8 x4, about a tenner plus VAT around here.

Cheers Adam

[John Rumm]

The trick seems to be to let it expand a bit before offering it up, then when you push it on, you squeeze most of the gas out. There is also a board fix foam which is designed to expand less than the normal one:

[Bert Coules]

I thought I did, but...

Phil L's boards are (if I understand correctly) 300mm x 5m and cost £10 each: that's ten pounds for 1.5sq m.

Yes, the Wickes version is 100mm x 2.5m, but they cost £10 *for a pack of five*: 1.25sq m.

So the costs are much closer than you and I thought. Even more so if Phil's product price doesn't include VAT, which the Wickes price does.

Bert

[Bert Coules]

That's fascinating. I thought it would be far more.

NT

[Bert Coules]

It's probably just me, but I've never had much luck with expanding (or even minimally-expanding) foam: horrible, messy stuff which goes everywhere and is next to impossible to clean up properly. Mind you, I've only ever used the self-contained spray cans; I've been told (here, I think) that the gun-type canisters are a lot better.

Bert

[Bert Coules]

That's a particularly big downside for my application: sticking whatever I use to the foil-surfaced Celtox is definitely my preferred option.

Bert

[Bert Coules]

The best price I've so far found is from The PVC Trade Centre: £9.14 incl VAT for a 300m x 5m length, with free delivery:

.

That works out about £17 below the cost of the Wickes 100mm t&g for the area I need to cover. A decent saving.

Bert

[NT]

How would you get more than 100g of cement to soak in? I dont know what the weight ratio of dust to water is, but you'd be talking kilos of water just to get 100g cement into the board.

NT

[John Rumm]

They make it easier to apply...

for board fixing, you just squirt a bead of the stuff around the board a few inches in from the edge. A few extra dabs or line to fill in the big gaps in the middle. You can do that with it laying flat or lent against a wall. Then leave for a min or two and push into place.

Get a can of the foam cleaner (basically a large aerosol acetone spray)

- cleans up the wet stuff easily.

[Bert Coules]

Thanks for that. I might give it another go, once I've decided on the cladding.

I've usually had a problem with the stuff going off too quickly to clean while it's wet.

Bert

[Phil L]

Aye. That £17 will pay for the adhesive - I used 1h caulk when I put it on my kitchen ceiling and bathroom walls 3 years back and it's solid, but on the ceiling I fixed it with half inch screws through the groove side prior to slotting the next piece in. You'd probably be better with an instant grab adhesive if you can't get a mechanical fix

[Bert Coules]

Yes, that's what I've used before, with the Wickes 100mm version. Obviously, length for length the 300mm will be heavier, but I imagine something like Evostick's Sticks Like... will hold it perfectly well.

Bert

[John Rumm]

I usually find it takes half an hour or so to skin over - and even then its usually still full of wet stickyness if you disturb it in any way.

[NT]

I presume PVA would work too, but would need a few dilute coats to soak in as far as possible.

NT

[Bert Coules]

I think I'd be happier with that as an alternative. Thanks for the thought.

Bert

[fred]

Way too heavy for gluing in my view and any damp ingress could make for a dramatic failure. Without additional mechanical fixing I would stick with the plastic, 6mm ply or hardboard as a last resort.

How did you fix the insulation in the end? Did you go for the 50mm?

[NT]

The idea was to soak with pva to toughen it up some. I'd definitely have a few screws a board at least for the resons you say.

NT