Huge wrote:
On 2008-10-13, Tim S wrote:
Timothy Murphy coughed up some electrons that declared:

I want to make a hole in a plasterboard ceiling
to get access to the roof-space in my one-storey cottage.
I have found that the joists are 1 foot apart,
and am thinking of making the hole a little under 2 feet square,
which would mean cutting one joist.
and putting 2 cross-pieces to hold the joist.

Is this a job I can do myself? Or should I get a builder.
I'm reasonably handy.

Any advice or suggestions gratefully received.


**** As always with free advice on USENET, please wait around for a bit to
see if there's are any refinements on what I'm about to write and make sure
no-one disagrees fundamentally with what's below. ****


Well - it sounds like a pretty standard loft-hatch arrangement.

I assume the joists are only holding the ceiling up?

Aren't joists normally under tension loads, because they're preventing the eaves
from being pushed outwards by the pitched roof?

Mmm. In a truss, yes. with no load above the ceiling apart from end
pinned trusses.


But there are other ways to make a roof..warren bracing and purlins etc.

Purlins put them into compression, by and large, and a warren truss will
introduce bending moments. As will any loft load.