On 22/05/17 09:50, Tim Watts wrote:
Very hypothetical...

http://www.wikihow.com/Build-a-Gambrel-Roof

How strong is that? There must be some not insignificant spreading
forces going through those gusset plates.


Symmetrical loading won't impose partucularly large forces.

But the gussets can take it.

In essence consider whether the gusseted rafter would break at the
gusset or elsewhere under load.

Once the answer is 'elsewhere'. its strong enough :-)



I am wondering - as I am musing plans for my workshop, long term project
as the house is nearly done (yea!).

Going for 15m2 to use permitted development (near 2 boundary fences,
wooden, so limited to 15m2 and 2.5m roof height).


I have always thought a gambrel roof would look pretty - but this has to
take some load: snow load, tiles (synthetic, so not as bad as
concrete/clay) and hanging/storing stuff in it.

It's not as easy to visualise the strength as a simple pitched roof with
tie beams.

You could tie the top section for extra strength.

And put in verticals in other places. The ply skin adds a huge amount of
strength in all other directions

However in this case I would pay a structural engineer to sign off any plans

Then you can sue if it falls down


--
€œBut what a weak barrier is truth when it stands in the way of an
hypothesis!€�

Mary Wollstonecraft