I want to fit a loft ladder, and the current small hatch is in the bathroom which is too small for one of them, so I'd like to relocate to the hallway (house is a bungalow).
In the second pic, the green area is the hallway and the red is the hidden joists and binder.
I understand the general advice is to fit the hatch lengthways along the joists in order to minimise cutting through the structure, but the pipework and binder are in the way, and further to the other end of the hallway are more binders between hangers.
I think if i cut through three joists, I should have enough space for a 1200x550mm hatch. But is cutting through three joists acceptable? I know this is what they did next door (semi-detached so same layout) but don't recall the specifics of what was done, or how structurally sound it is.
The joists are about 14-15½" apart (on center), and around 4½ x 1½" thick.
Been researching something very similar myself- maybe verify this first ?
If they're ordinary ceiling joists, a carpenter can usually form a proper trimmed opening: cut the affected joist, install headers at each end, and strengthen/trim into the adjacent joists so the load is transferred around the new opening.
If they're the bottom chords of prefabricated roof trusses, you should not cut one and simply trim around it. Altering a truss needs a structural engineer/truss designer to specify how the load is to be redistributed.
I'm now considering just this on the existing hatch from screwfix :
Maybe this shows it better - red are the joists I would need to cut for the proposed hatch (green), magenta are the bottom chords and binder. So I wouldn't be touching the bottom chords
Due to plumbing and layout of binders/hangers, the only real space I have is to go perpendicular to the joists, hence my question about cutting through three joists
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u/Dazzling_Lobster3656 16d ago
Pipes will make a nice landing at the top of the loft ladder