Loft Hatch Enlargement - see the groovy graphics

[thiambal]

I currently have a loft hatch which - if looked at from the joist side is constructed like this


j = joist
n = nogging

jj jj jj jj jj - not to scale (but my joists really are
jj jj jj jj jj made of lots of little J's
jj jj jj jj jj honest!)
jj jjnnnnnnnnnnjj jj
jj jj jj jj
jj jj jj jj
jj jj jj jj
jj jj jj jj
jj jjnnnnnnnnnnjj jj
jj jj jj jj jj
jj jj jj jj jj
jj jj jj jj jj

I really want to make this hatch bigger - it is just a little too small. My main question is this.....

How do I do it without the whole damn ceiling coming down?

From what I can make out - the only thing supporting the joist that has been cut to create the hatch is the nogging which it nailed to the end of the cut joist and the joist either side.

If I remove one of the noggings to further shorten the joist what is supporting that joist - it is just resting on the wall at one end and then the ceiling.

The ceiling is curently constructed out of lathe and plaster with plasterboard nailed over it (not by me).

The second question is - if I can remove the nogging safely - what is the best way of the cutting into and removing the section of ceiling?

 

[mark_j_k]

Our loft hatch used to to small - 18" by 12" so I decided to enlarge it.

I have created some crude drawings (not to scale) of what I did:

The ceiling and hatch as it was:

Firstly I attched some 3x2 around the hatch area before I cut the centre joist.

I then proceeded to remove the old hatch frame and trim the lath and plaster back to the extent of the new hatch. Then I cut the ceiling joist that was in the way for the new hatch.
Once the new opening was created, I attched the 2 new sides onto the joists. Securing them in the middle first, then on both sides.

Once the new sides were in place then I removed the temporary supports I attached first.

Lastly, I made a frame for the new hatch to sit in.

I havn't finished it yet, for a hatch I've got an old piece of kitchen worktop which sits nicely in the hole and doesn't rattle when the wind blows! I still have to patch up the plaster around the hatch as well.[/img]

 

[thiambal]

Excellent, wow - thanks for spending all that time on drawings - I have since noticed that my groovy graphics on my original post did not traslate across properly - so there is just a mess of letters - sorry.

Anyway, I followed your advice - and nothing collapsed so success all round.

Thanks again for the advice - you are a king amongst men.

 

[peterd]

What mark_j_k suggests seems OK.

I would sugest strengthening the outer joists however.

The inner joist (which you are removing) wants to span like the two outer ones....probably onto a bearing wall or something suitably stiff.

Now it's spanning onto a transverse joist, which in turn transfers the load onto the two outer joists.

The outer joists are picking up additional load therefore.

Also make the transverse joists the same depth and type as the longitudinal/outer joists.