On 22/05/17 11:13, T i m wrote:
On Mon, 22 May 2017 10:39:51 +0100, Tim Watts
wrote:

On 22/05/17 10:00, The Natural Philosopher wrote:

You could tie the top section for extra strength.

That is certainly possible.

So your 'roof' would actually for part of the shape of the structure,
rather than being a roof over an existing/separate floor/roof, as per
the example in your link?

Yes - very typical 4x2" framed shed sort of thing


I ask because I assumed the 'tie' would have been provided by the
ceiling of the existing structure and with only 2.5m high to the top
ridge I'm assuming you would have to put ties across at maybe the
first joint (as TNP suggests) to be able to store stuff in the roof in
any case?

I think ties at the top level will work well - will be around 2m off the
floor.

It would be ties at the base of the roof that would be hard - although a
tension wire hooked up to the ridge and down the other side could be an
option (sure I've seen that in a real large roof somewhere once).


Basically I's imagine that unless the gussets were 100% strong enough
to stop the base of the roof splaying under *any* (worst case) load,
then you would probably need ties somewhere?

That's what I'm wondering. Or buttresses outside (that would look a bit
heath robinson!)




And put in verticals in other places.

Not possible here as they would become columns to the floor.

Interesting project idea / project though, I could do with more space
in my garage / workshop roofspace but with the walls already 8' high
there isn't much room for a gambrel roof (and stay under the permitted
development limits). ;-(

I'm building on a slope - the PD tech notes say measure from the highest
local ground to the highest point on the building.

So I might be able to buy a foot or so legitimately. It was my plane at
least to dig it into the ground a bit so the floor structure was lost
downwards and the entry was dead level with the lower part of the hill.