Any roofers here?

[nothanks]

I'm starting to plan a garage extension (it's used as a workshop and I'm running out of space) and am trying to decide whether to go for roof trusses or to cut the roof on site. The garage roof is rather like a pyramid, with a 60 degree pitch, and is made from large timbers radiating from a king post that's supported on an oak beam across the garage width, which is about 5m; effectively it's 4 hips that form the roof. The plan is to increase the depth of the garage from about 5.5m to about 8.5m by bringing the front forwards and supporting the existing roof structure on an RSJ where the doors currently are. The new ridge and hip could either be pre-made trusses or cut on site, but at the moment I'm favouring trusses because of speed of erection and defined cost. Whichever, the tricky bit is connecting the new roof structure to the existing hip, and this could either be cut on site or achieved (I think!) with reduced trusses built off the existing hip corner timbers. Thoughts, suggestions and sensible comments gratefully received.

[Roger Mills]

Do you want to use the roof space for storage? Trusses get in the way of that big time!

[Adrian Caspersz]

Inspiration:

Father & Son Build Their Dream Garage During Lockdown | Pt.1

Are there any British companies selling kits like these?

[nothanks]

The house attic is quite large (plus a couple of sheds) so there's no need for storage.

[nothanks]

Thanks, that's interesting but in my case I only need a few metres of cavity walls to extend the existing structure, they will then be roughcast to match the rest of the building.

[Fredxx]

Personally I would always go for making your own roof structure, simply for storage and versatility. The cost isn't normally that much greater though without knowing the with/peak it's difficult to judge. I would size timbers so I didn't use collar ties.

Oversizing the ceiling joist also allows hoists to be used.

Of course roof trusses don't prevent storage, it just becomes more problematic and less efficient.

[nothanks]

Yes, that's what I did in a recent extension but it took much longer than erecting pre-formed trusses and cost quite a lot more (hindsight!). I don't need to use this space for storage, especially as the ceiling is higher than usual.

True but the new RSJ would provide that.

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