Need to choose "weatherproof" chipboard flooring system

24 Jul 2015
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United Kingdom
We are about to strip a barn roof and not quite sure when it will be weatherproof again. Using prefab trusses and the guy putting these into position is also going to lay the floor. The bedrooms will be in the roof space with velux windows.

I need to get some chipboard ordered that will withstand being open to the elements until the building can be made watertight, just in case trades are not available.

If anybody has experience of using these weatherproof systems i would be grateful for any advice

I can see there is Egger Protect which only needs their glue to seal; they say this can be glued down in damp conditions and will be ok for 60 days exposed according to the Egger website. They also say you can tile direct on this floor.

There is also Caberdek; on the video it says joists should be dry when being glued otherwise the floor may squeak. The joints also need to taped to be waterproof, but them the whole layer can be peeled after the roof is on. Can also stay exposed for 42 days using their system

Also there is Cabershield plus; which seems to be similar to Egger Protect, except it does not seem to be so well stocked. Lasts 42 days in the open

Any comments welcome to help me chose although i guess it comes down to price in the end but also the truss erector who is laying the first floor has used Caberdek so maybe i should stick with what he knows ....
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Why do you specifically need chipboard? Personally I'd go for water resistant plywood. It'll cost 3 times as much (approx 10 pound/sqm) but you'll have a floor that won't be damaged by water.
Chipboard system is very quick to lay and it's what the builder is used to

Apparently moisture proof chipboard has come on a lot in recent years
I doubt plywood is any slower to lay. Standard floor boards would be slower due to the quantity.

Our architect specified plywood for all flooring and roof decks. The builder substituted osb3 for the roof deck. My only experience with chip board is unfixable creaky floors being blamed on it and holes caused by water damage..
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why not approach the problem differently/use materials that are going to end up somewhere else instead; temporarily throw down whatever you're sarking the roof with, as flooring to walk about on while the trusses are fitted, then sark with it, then fit a floor.. or perhaps you're using sheet materials somewhere else, but can delay using them in that somewhere else while they're being a temporary floor
Thanks cjard

We are removing old chipboard that boarded out the roof space before; if we were to temporayily put it back there is the problem that awful weather and lack of trades mean a high risk it will turn to mush

John; thanks for your experience. You say the builder changed your plyfloor to OSB ...there we have it ... i am not sure i can trust the builder to be able to cope with anything outside their field of what is the 'right' way to do things. I am no expert, but a ply floor would mean being careful to butt up each sheet to the next and fix with screws or nails. It is also very heavy. Chip board is tongue in grove and easy to fit together and basically just needs to be glued and them you get a smooth surface finish with no gaps. My gut is that ply is 'better' but practically speaking, moisture proof chipboard may suit our situation. No offense to many of the splendid people who post in these forums. Our roof builder does not read our emails, hard to get hold of, but i am told he is a good worker. Changing the game at this stage is too much of an unknown ... new quote etc
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Chipboard boarding in a roof space might only be thin stuff intended for putting boxes on, not a 100kg guy carrying a 50kg roof truss... but if it's strong enough, you could do worse than rolling out a sheet of dpm on top of it to keep it dry.. it's not expensive, and the dpm will have a use elsewhere (under the garage slab, pond liner, keeping other materials dry..) later.

TnG OSB and ply are available, though the waterproofed chipboard is good stuff, and not particularly expensive. You can even get eggerdeck in a decorative finish if there are areas of the build you don't care to put a proper decorative flooring on, but dont want it a ****e-up-with-plaster-snots grey (the decorative eggerdek has a peelable plastic top layer)

In terms of spacing, for joists at 600mm, 22mm boards are required. At 400mm spacing, this can be dropped to 18mm
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very interesting post. I think the old chipboard is pretty thin so won't persue ... good idea which may help someone else though. I will look at the decorative eggerdeck; thanks for the tip.

Today is a very wet day ... fills me with dread. Praying for good weather in a couple of weeks.
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egger protect is very good for wet conditions ( better than caber crap) we use it alot on attic truss roofs and never have any problems with water damage if glued correctly its a lot harder than most chipboards
so if you use mechanical fixings put a dob of glue on the heads to keep water tight

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