Insulating the roof of a garage.

[krypton]

Hope you can advise me here!

I am a maintenence man for a community centre, the age of the buildings range from victorian to built last year. It is used day in day out by many groups etc etc.

There is a large garage in a rear yard to the buildings. It was built by the local boys brigade in 1975 for the storage of their tents.

They are reporting that they get lots of condensation dripping from the roof which is made of some kind of corrugated matierial. Supported by long beams going up to maybe a 20degree angle for water drainage.

I was thinking of getting some fibreglass and then putting plywood over it, making sure the fibre glass didnt touch the actual roof.

Would this solve the problem?

Regards

 

[lincs1963]

It almost certainly would

 

[krypton]

Cool thanks Does anyone have an idea to how much i should be paying for plywood? I just looked on B&Q and it was very pricey!

 

[Digit]

OSB should be cheaper than ply.

Roy.

 

[srp]

A waste of time unless you put a breathable membrane immediately under the corrugated covering, with the insulation underneath, followed by a vapour barrier and then the plywood (or it could be something cheaper like plaster board). Really speaking, you'll have to strip the existing roof. If it is corrugated asbestos cement then you might be better leaving it alone.

 

[Eric The Viking]

I've got a 1960s Marley concrete panel double garage. Originally it had a very thin steel ("coil coated") corrugated roof, with a single pitch, sloping down front to back. During the autumn/early winter the predictable always happened - it rained on the inside (condensation).

I found an industrial roofing firm who did garage roofs as a sideline. I discussed the issues with their surveyor/estimator. Following his advice, they retained the original roof, added 2" tall steel battens on top (tied through to the steel joists), filled the gaps between with insulation then new coil coated steel (industrial grade this time) on top.

I can now safely walk on the roof. The condensation problem has pretty much gone (not quite, because of the building construction, but it's MUCH better), and the noise of machinery in use is quite well muffled. The total bill was about £1500, but that was probably less than a DIY + paid help effort, and I've not lost any roof space.

They said they also do pitched roofs, and replace asbestos too. The sheets used for the new roof have a 'hairy' coating on the inside surface, which stops them vibrating and helps stop drips forming. The rep told me they pretty much eliminate condensation drips by themselves, although our new roof arrangements are much better for heat retention too.

There are quite a few such firms around I think, so worth looking. I know you'd appreciate a DIY solution, but honestly, I'm really glad I didn't do that now.

HTH, E.

PS: If your avatar said where in 'England' you are, someone might have a recommendation!