On 8 June, 09:29, Cicero wrote:
On Mon, 08 Jun 2009 08:10:42 +0000, neverwas wrote:
I am thinking or replacing my (leaking) flat carport roof ....

snip

notch each joist to achieve a fall ....

Easy to overlook after all the good comments that it is a flat roof. But I
mention it to ask if you are suggesting that the OP switches to a sloping
roof? *If not, how would one go about preventing all/much drainage from
the roof down the wall?

=========================================

The OP is going to use Onduline corrugated sheets which are 2 metres long,
so an overlap will be needed to achieve sufficient width to create a
carport. Given that an overlap is required the roof will need a slope to
prevent water ingress at the overlaps. This suggests that the OP will be
making a sloping roof regardless of the existing format. In any case
'flat' roofs usually have a fall (slope) to allow drainage to a gutter so
they're not entirely level.

Cic.

--
==========================================
Using Ubuntu Linux
Windows shown the door
==========================================

Definitely use the nominal 4 x2 size of timbers - in fact I did a 2.5
m wide roof with Onduline recently and used 5 x 2 as even that span is
approaching the limit for 4 x 2 - and that doesn't allow for the fact
that modern timber sizes are well below the nominal. You do have to
walk on the roof to do the fixings, which you certainly couldn't do
with 2 x 2.

I think if I remember the instructions were pretty comprehensive and
I'm not aware of finding anything special to pass on, but if you do
have any questions don't hesitate to ask.

I certainly would always suggest Onduine now for any shed roof - so,
so much easier and vastly quicker than felt, and really no more
expensive.

Rob