On 22/05/17 13:34, Bob Minchin wrote:

I reckon this is a non starter for 2.5m ridge height. Note that the wiki
article shows a flat deck on which the beams bear. this is critical to
the strength as it will be in tension to support the roof weight. Even
if you replaced this with horizontal joists they would end up around
chest height.
If you want to stay within PDR then there is little option but to have a
very very low pitch roof

I'm starting to think you're right Bob.

which rules out most tiling systems and you
possibly will have to go with EPDM rubber which is practical but not
pretty.
Bob


http://www.ecosystemsdistribution.com/eco-slate/

10 degree pitch. I've had my eye on these for a while...



It's either that or sink the structure into the ground a bit to gain
some extra height - but there's a limit as anything other than a gentle
ramp down isn't a great idea for a workshop.

I've got an awkward corner plot with the house set back to boot - that
gives me two front elevations that I cannot build beyond (PDR) and
forces anything else to be near a boundary.

I am glad the old 5m from house rule was scrapped!

I also have a shared sewer I need to stay clear of (I'm going to sink
footings about 1.5m away and at the same depth or slightly lower and
have about 50cm of overhang on the base (cantilever).