Spray foam insulation

[Muddymike]

Have any of you had commercial type building roof interiors foam insulation sprayed? If so what did it cost?

I cant find a cost per Sq m just many requests to complete a quotation request form.

Mike

[tabbypurr]

great way to destroy a roof structure

NT

[ARW]

Commercial roof structure could mean anything. But probably not wood and tiles which it what the foam destroys.

[Brian Gaff]

Yes its not very breathable falls off pushes off tiles and pongs lot as well. bah humbug. My loft however is open to the elements, ie you can, if I could see see out between the times. It seems that no lining was ever fitted as there is no evidence of fixings. The good thing is that it does not have rot, the bad thing is the wrong type of snow powdery, gets in. And muck. Brian

[Kipper at sea]

If its the foam that you refer to is the one that is sprayed to the back of the roof, tiles and lath, it will be the biggest mistake you'll make. If y ou ever have to do a repair or a slate or tile gets broken, its a very expe nsive job to do, that if any roofing company will take it on.

[tabbypurr]

trapped water rusts steel as well as rots wood. Wood & steel covers most roofs.

NT

[alan_m]

My neighbours' house has this spray on insulation[1] but when it was done the neighbour at the time was sold on it as a cheap method of stabilising a slate roof reaching the end of its life with more slipping slates each year. I avoided the "we are next door and can give a substantial discount if you sign up today" offer for the same service.

When I had my roof replaced a hidden gutter had to be installed between my roof and my neighbours roof (terraced property). My roofer wasn't too pleased when he found that my neighbours slates had been glued down with foam when removing them to install the gutter. My roofer commented on my neighbours roof as a property to avoid if ever asked to quote for any work on it.

[1] Foam sprayed to the underside of the slates gluing them to the rafters/purlins

[tabbypurr]

k of the roof, tiles and lath, it will be the biggest mistake you'll make. If you ever have to do a repair or a slate or tile gets broken, its a very expensive job to do, that if any roofing company will take it on.

It makes the slates impossible to get off in 1 piece and re-use. It also tr aps water against the timbers & makes them impossible to inspect. A crazy i dea.

NT

[Andrew Gabriel]

Same situation with my brother's roof - neighbours had been sprayed with this stuff, but fortunately my brother's hadn't.

When the roofer did my brother's, he warned him that if he spoke to the neighbour about having his done, it would be *much* more expensive. Reason is that it apparently takes 10 times longer to strip the roof, and only then will you find out how much of the structure (e.g. rafters) needs replacing. Also, old roof tiles can't be used as hardcore as they can't be separated from the foam and battens, and you end up paying to landfill them, and the volume is always very large.

[Muddymike]

I was thinking of my workshop which has a steel frame with timber purlins supporting corrugates asbestos.

Mike

[tabbypurr]

hopefully you've now thought better of it.

NT

[Muddymike]

Lots of opinions against but there's yet to be anyone with experience of the system answering my original question.

Mike

[tabbypurr]

I don't think anyone here has been unwise enough to use it

NT

[Andrew Mawson]

I had my corrugated cement / steel purlin roof of my barn, which I was turning into a workshop, foam sprayed 9 years ago and it has been absolutely excellent. We aimed for 100 mm on the roof and 75 mm on the walls, which were then faced with 18 mm OSB3. about 40 x 40 foot and it was around £4K then.

My only regret is that they failed to seal the apex properly leaving a gap that the occasional bird gets through. It has made an enormous difference to the comfort level.

Andrew

[Tim Watts]

Are you specifically thinking of metal roofing?

[Muddymike]

No, asbestos roof, steel structure, wooded purlins.

Mike