Roof advice?

[shed9]

About to put a metal box profile roof on a large shed structure, its had DPM over a plywood roof over the last few months which has done a remarkable job of keeping weather tight although its got a little damp in the odd patch.

Anyhow, I've stripped the plastic back to access any flaws or changes in the plywood top. What would be the best approach to place the metal sheeting? Batons and metal roof straight over or put a sheet of plastic back over the ply before batons and metal sheet.

Any help appreciated.

 

[Myfordman]

I'd be tempted to put a breathable membrane over the ply than batten and metal sheet, just in case there is any condensation or minor leaks on screw holes under the metal.

 

[shed9]

I'd be tempted to put a breathable membrane over the ply than batten and metal sheet, just in case there is any condensation or minor leaks on screw holes under the metal.

Thanks for the reply Myfordman

Yeah, I'm starting to think this. The metal will get warm and get rid of any moisture anyhow but impermeable won't allow for this.

Any recommendations on sheeting.

There is this stuff from Screwfix;

http://www.screwfix.com/p/roofers-choic ... -50m/70075

 

[Myfordman]

I used the slightly heavier one - protect brand 180g /m^2 also from screwfix but if you are careful not to snag it, then the one you suggest should be fine at 100g/m^2

Its been up there about 8 years now and all seems well.

hth

MM

 

[busy builder]

I put these roofs on garages etc all the time, usual is non structural ply or OSB Sterling board, breathable membrane then profile sheet.

 

[midnightlunchbox]

The profile sheeting is prone to condensation, and the anti condensation stuff doesn't work. Definitely keep your plywood sarking and felt/roof shield over it.

 

[busy builder]

Yes agree, if ply ok then you could always just put profile sheets on top.

 

[angelboy]

I've just done the roof in this:

http://www.ebay.co.uk/itm/Breathable-Me ... 19c65a99ae

Based on advice from another forum member - I'm also covering the walls in - Half the price of the screwfix stuff!!!