"Tim Lamb" wrote in message
...
In message , David WE Roberts
writes
The roof is nearly done - i.e. at least half way through.
http://s817.photobucket.com/albums/z...ther%20of%20al
l%20Sheds/
The roof woodwork is certainly solid - I can jump up and down on it with
no visible deflection of any of the beams.
Perhaps a little over engineered?

Just a tad. The barn I am part way through cladding has 9"x3" timber
purlins spanning 15' bays at around 4' spacing. This supports 80mm
sandwich insulated steel sheet.

Now waiting for the wind to drop a little before putting up the metal
sheets - although rain is now forecast for tomorrow :-(

Don't forget the butyl sealant strip along the roof overlaps. The simplest
method I have found is to turn the sheet over on the ground, apply the
sealant strip to the lap, peel off the paper protection and get help to
lower the sheet vertically into position. You don't get two goes so be
exact!

I may have mentioned before.... be aware that these roof sheets are noisy
in variable sunshine. Thumps and bangs from expansion.

No butyl sealant strips involved - just an overlap of the profile.
I have remembered that I have to paint the woodwork with bitumastic paint
before putting down the roof sheets to avoid a reaction between the metal
sheets and the chemical preservatives in the wood.