Widening loft hatch

[ElwoodP]

I have a very narrow loft hatch that I want to widen to put a loft ladder in. I plan to cut one joist and construct a wider frame using joist hangers. Please see photos.

Do you think its OK for me to cut the joist or should I get a professional in to check? Does the plan look suitable?

Photos:

https://www.dropbox.com/s/qdzfi1ik4gcldvv/plan.jpg?dl=0
https://www.dropbox.com/s/zs3tzf4gbirg13c/from-below.jpg?dl=0
https://www.dropbox.com/s/5awu2p17fjq457s/context.jpg?dl=0

 

[Lower]

Where you cut the joist to make the bigger hole you need to frame the two floating ends of the cut joist across to the adjacent joists. Essentially, in your plan you need to extend the two purple joists you're putting in so that they join up with the joist on the left. This would effecitvely make a bigger hole than you need but your don't need to use all of it as a loft ladder with hatch normally comes in a frame.

I wouldn't use joist hangers either as joist hangers are only designed for joists to hang from them so loads in one direction. I would be screwing directly into the joists to make the join.

 

[Tigercubrider]

You can also add a reasonable amount of timber to the "new" joists to reduce the size - hopefully before you cut the plaster.

I.e. Cut the joist , add new wood to hold it all together( screws not nails) then size up the opening needed
Possibly a couple of bits of scrap to temporarily stabilise it while doing this

Then if the new framing needs packing, add some wood

 

[ElwoodP]

Thanks guys.

@Lower, if I understand correctly I think my plan is already as you suggest. I think maybe the photo isn't clear. There is a joist making the left hand side of the current opening, you can only see a bit of it as some insulation is sitting up over it. This joist is much closer to the one on its right (that I intend to cut), than the regular distance between other joists. Immediately to the left of this joist is an RSJ supporting a brick wall. To be clear my intention is to join the horizontal noggins to meet the existing joists on both left and right.

Updated diagram:
https://www.dropbox.com/s/itgqzu5wz6cma9t/plan-updated.jpg?dl=0