Hi, I've never done anything like this before so there may be loads of follow up questions to come. I've decided to build my own shed in the garden and I'm planning on roughly 4 metres by 2.5 metres. I'm only 5'8" tall so I was thinking the back would be fine at about six foot but what height at the front? I'd prefer a pent style roof so what height difference between the front to back should I have for a decent angle for rain to run off without chances of water running back under the felt onto the wood? I should say I'll be using Black Jack to stick the felt down so should not have any problems with the water running under but as you know if there is the slightest gap water will find a way. Also I'm planning on building the base with 3x2 treated decking joists for the floor base stood on 4x4 post "legs" on concrete blocks to keep it off the ground. Does that sound about right? Also how many "legs" would you recommend to support it? Glen.
See this thread, & the Youtube links, he give great advice & makes building a shed for a novice easy. http://community.screwfix.com/threads/shed-spec.186465/page-2#post-1495317 The Everbuild 904 Black Jack Roof felt & Chipping Adhesive is very good,
Thanks Kiab, I've watched all the vid's and they have been a big help, got loads of tips there. But they didn't really help with my questions, ie, what height difference from front to back for a pent roof? and how many "legs" for the base of a 4m x2.5m shed? Glen.
Sorry chippie, I may have explained it wrong. The front of the shed will be 4 meters wide and the depth 2.5 meters, so the span for the roof will be 2.5 meters. So what height difference should I have between the front wall and the back wall to get the right angle?
Before you work out the angle of the roof, what materials are you going to clad the walls in ? It would be pointless using Sheet materials and then having to rip them down to accommodate a set height. The same with the roof if you want you shed to be 2.5m wide you are going to have to match the roof timbers to your sheets otherwise the joints won't be supported and you don't want thin pieces of board at the edges of the roof.
That's part of the problem, I don't. know what angle I should have. It's still in the planning stage at the moment so I was looking at ship lap cladding for the outside walls and osb3 for roof and floor.
Decide where you are going to buy your timber and what you are going to buy. At the moment you shed doesn't fit a lot of common timber sizes (4m x 2.5m) Depending on where you by it is 1.8, 2.0 , 2.4, 3m up to 3.8. I would go to a shed supplier and look how their sheds are made, the sizes and measure the heights and widths etc.
The 4mx2.5m is a rough size I think the woods I've been looking at for the frame are actually 2.4m. The front and back I was thinking of making as two two meter panels and bolting together (maybe easier than trying to handle one four meter panel). For the floor, a local garden centre has 4 meter 4x2 treated fence rails would they be suitable as a base?
In answer to your question, I think you would need to look at the product you're going to use and see what the recommended pitch is. But for bonded felt flat roofs the pitch is just minimal so that water runs off and doesn't sit in a pool, something like 1:40 - 1:80. I used corrugated steel on mine, which had a min. pitch of 5 deg. If you're using OSB for the roof, you'll want some overhang, so the floor will end up smaller. Builders merchant is cheapest for timber where I am, treated regularised carcassing is probably what you want.
Was thinking of OSB3 for floor and roof, plus some screwed to inside for hanging things like tools up.
if you go here http://www.gardenbuildingsdirect.co.uk/wooden-sheds/expert-pent-workshop they post the measurements at the bottom of the page