Enlarging loft access

[NerdNot]

Hi, I'm planning to install a timber loft ladder in a 1900s end terrace house and will need to enlarge the loft hole. I've read what I can from other posts about doing this but would still value some advice. The ceiling joists are 4 X 2s with a spacing of about a foot giving an adequate existing access width of about two feet. I need to increase the length of the hole from its present 560mm to 1150mm (sorry for mixed units). There is a 3 X 2 trimmer supporting the "floating" joist which is cut shorter than the others to provide the access hole.
I'm intending to support the shorter "floating" joist temporarily with some hefty screws and a bit of stout timber going across the existing joists then cut out the hole. I thought I'd cut the shortened joist in an L shape at its end so that it was 2 inches shorter over the top three inches to take the trimmer but with the bottom inch remaining right up to the edge of the new hole. This might prevent the lath and plaster ceiling from being too badly damaged. Then I'll put a new 3 X 2 trimmer across this "notched" joist secure it firmly and box around the hole to make it neat and cover up the 1 inch gap between the trimmer and the lath and plaster ceiling.
Now my questions are:-
1. Is this OK?
2. Should I use screws or nails to secure the "floating" joist to the new trimmer, what size should they be and how many would you advise using, please?
3. Should I use the same method, using screws or nails, to secure the trimmer to the full length joists or would I be better using timber joist hangers (I've seen some "Jiffy joist hangers" advertised)?
I'd greatly appreciate the advice and opinion of you experienced folk. Apologies for any wrong terms or poor descriptions.

 

[tony1851]

Screws should be OK, but there is a danger of splitting the end-grain if you dont drill pilot holes first.
You could use joist hangers to support the trimmer on the continuous joists instead.
Fixing the cut end of the original joist to the new trimmer could be tricky; the screws will be fairly close together so be extra careful to prevent splitting; it would be tricky to get a joist hanger in here.

Untitled

• tony1851
• 24 Jun 2012
• 1

 

[NerdNot]

Many thanks Tony, both for the advice on screw sizes and pilot holes and for the brilliant drawing which is exactly how I was trying to describe things. I was thinking of considerably thicker screws and I was concerned they might split the joist, but I'm now reassured that you think a couple of No 8s will be enough.

If anyone has advice on which is the best loft ladder to purchase that would be good to receive too. I've decided to go for wood, which I assume will be quieter than aluminium - after dust and general grot from my loft has invaded it anyway. Floor to top of joist height is 3.2metres which would seem to restrict me to AmbMid £194, AmbLux £270 or Eco3 £172 including the necessary extension. I'm told the AmbLux has better retracting gear but I wonder if it is worth the extra £76?