On Mon, 22 May 2017 13:26:30 +0100, Tim Watts
wrote:

snip

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

I helped put up an apex roof type wooden 10 x 6 shed the other day
that was modular (5 x 6 x 2) and the middle truss was, useless. If you
put it in place and put any weight on it you could feel it sagging /
collapsing. It wasn't even the same profile as the two ends of the
building and they stated in the instructions that the roof wouldn't
carry the weight of a person.

We rebuilt the truss (properly, with a tie either side and at a lower
level) and daughter sat on the roof putting in the felt tacks and it
didn't move at all. ;-)

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).

Yes, a pair X ties like that can work well. Isn't triangulation
clever. ;-)


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!)

Well, they could be made to look ok, many Churches have them as
features after all. ;-)




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 worst case for you then. ;-(

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.

Yes, I think keeping something as low as possible (subject to drainage
and holding back any cut-away land etc) all helps it to become less
visible. ;-)

Cheers, T i m