Shed floor & roof

[RobinClay]

In the garden of this old house we have bought is a shed, two sides of which are formed by the old stone boundary wall.

I want to extend this along one wall until it meets the next wall, i.e. the extension will comprise just a front wall and a roof. One slight complication is that the side wall is at 45 degrees to the rear wall, so the extension will be longer at the front (4825) than at the back(3100). The depth is 1870 from front to back.

I have placed 4x2 floor joists at 400 c/cs, running from front to back, resting on three longitudinal joists (at front, back & middle), which in turn rest on dpc on levelled concrete blocks. The top of the joists is 30mm below the existing floor level. All timber is either Tanalised / Celcurised or Cuprinoled (none is new).

1. What is the best / cheapest (contradiction, I know!) flooring to use ? "ordinary" ply, WBP ply, OSB, green chipboard, blockboard ... ?


For the roof, I shall use 2x2 joists supported on the studwork at the front and on the wall at the side & back. It'll be felted, but

2. What is the best / cheapest (contradiction, I know!) roofing to use ? "ordinary" ply, WBP ply, OSB, green chipboard, blockboard ... ?


What would *you* use ?

 

[big-all]

i would use 18mm exterior ply
but you i am sure you will choose osb/sterling board off 18mm

 

[RobinClay]

i would use 18mm exterior ply
but you i am sure you will choose osb/sterling board off 18mm

Thank you. For both floor & roof ?

I had thought to use OSB for the roof and WBP for the floor...

What's the difference between "exterior" and "WBP" ? (and who the hell would ever want to boil it, anyway !).

Should I also Cuprinol it? Both sides ?

 

[freddiemercurystwin]

who the hell would ever want to boil it, anyway

'boil proof' is the test that boil proof plywod must undertake ie it is suspended in boiling water for a set period of time to check it does not delaminate as this is considered to be a suitable test of the adhesives.

 

[scbk]

I have found that by the time you buy some half decent ply and strong felt it's almost the same price as corrugated iron, which will last for decades without any maintenace, unlike felt. But it won't suit all roofs and uses!

 

[big-all]

yes go for ply on the floor but sit down before you find out the cost off them

for my shed 10x12' the txg shiplap was £260 the 9 sheets off 18mm ply was more 3x3/4 sheets for the floor the rest for the roof

the pitch off the roof was decided by 6ft+6ft overhanging 6"all round gave a 30% pitch
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