"David" wrote in message
...
On Fri, 09 Apr 2021 17:22:04 +0100, williamwright wrote:

On 09/04/2021 13:22, David wrote:
I'm trying to work out what weight can be safely put on timbers
supporting a shallow sloping roof.

I potentially need to get up on the roof to service the plastic
covering and also the flashings at some points.

My embryo plan is to construct some crawling boards which won't slip
(essential) and will carry my weight (around 168 pounds) and some
tackle.

Possibly 2 or 3 boards so I can work my way along from board to board.

First I need to know if the timbers will support my weight, though.

Cheers


Dave R



Do you mean 5" x 2" spanning a metre? You could park a car on that.

Bill

Sorry, not enough information.
Posted in a hurry to remind myself then haven't got back until now.

Rafters made from 2 * 5 timber.
Centres (gap between centre of two rafters) 1080 mm.
Length of rafter (not mentioned) roughly 2.3 metres.

Thinking of it as a sloping floor I would expect
somewhere around 400mm centres.

But thats because it has to take furniture and lots
of people at times and its unpleasant if its too bouncy,
not because the joists would collapse with one person.

At least that is what we have in the loft with 4 * 2 joists.