diy question

[gucciman]

i would like to make the hatch to our attic larger, ive had a look and the ceiling beams are in the way and need cutting. is this a job for a diy'er or should it be left to a carpenter or builder?

[Hard@it]

B & Q have ready made hatches for �25 -30 or so, I think your joists have to be 600mm apart,and that would only mean cutting out and inserting between your joists.There is a flange face so if you were careful you would not see faults

[buildersmate]

It entirely depends whether you have roof trusses or a 'cut' roof. Roof trusses are prefrabricated triangular sections of roof that arrive on building site ready made. Most estate houses built in the last 30 years have these. You must not cut the bottom of this triangle, because it destroys the strength. If you have a cut roof, there will be purloins (massive horizontal timbers running mid-way up the roof, from one end to other). In this case, the joists just above the ceiling are there to hold up the ceiling plasterboard, not support the tiles on the roof.

If you proceed, cut out the section you desire, then nail two cross-pieces at 90 degrees to the joists to act as a support round the edge of the new larger hole. The cross pieces should extend to the next joists across on each side (to the one cut through). Ceiling joists are usually spaced 600mm apart, which is why B+Q supply hatches this width - you can't get much larger without doing the above operation.

[gucciman]

thanks guys

i think the job is complicated because the exisiting hatch has been fitted across the joists rather than length ways between the joists. this is because the hatch is above the stair landing in a corner with minimal access on two sides because of the walls and the banister and a very long drop down the stair on the other side.

if re-arranging the joists would the ceiling need to be supported with a screw jack whilst doing it?

[Hard@it]

Do not think about cutting the joists yourself if you have no knowledge,get someone in. Have you thought about resiting it to another area, say a bathroom ?

[buildersmate]

First thought, can't you relocate the hatch somewhere completely different on the landing more convenient and get a plasterer to skim the filled-in hole?

If not, I guess you have a 'cut' roof or you wouldn't be still contemplating this. Then the answer is, it depends what's sitting on the joist you intend to cut (in the loftspace). The weight of the plasterboard hanging from it isn't huge, so I would have just pushed a piece of 18mm ply against the ceiling and jammed a suitable length of 4x2 between the floor and the ceiling - just to hold the weight of the plasterboard. Beware joists with water tanks sat further along to them - they support a lot of weight and the tank should anyway be over a loadbearing partition.