Has anyone here made a wooden folding loft ladder?

[nothanks]

My house has a very large and boarded attic and I want to make access easier by replacing a flimsy metal loft ladder that someone fitted in place of an original wooden ladder. The existing trapdoor is quite large (690x1450) so I'm tempted to make my own replacement ladder to avoid having to put filler pieces in the ceiling - either a 3-section z-fold or a 2-section slider. Making the ladder would be straightforward but it's going to be heavy (especially when connected to the trapdoor, which is timber framed and solid) and I can't see how to counterbalance it safely. I could set-up 2 wires to pulleys on a purlin and use weights, but the load will change as the ladder hinges down. Springs would change their rate and probably do the job, but I can't see how to design the mechanism and trial'n'error would be a pain. I may give-in and buy an off-the-peg loft ladder, but it would be useful to hear whether anyone else has tackled the same problem.

[Brian Gaff (Sofa 2)]

My main problem is all the muck that comes down when you open it. Its one of those concertina ladders. Brian

[Tricky Dicky]

We had a 3 fold z type at the last house cannot remember who made it but it had some spring assistance to heave it up but I did get to think as I got older it became harder to push up and certainly not a job for a little old lady!

Richard

[newshound]

It's potentially quite a complicated design problem, a lot depends on the clearance that you have above the hatch. A common way to cope with the fact that load varies with geometry is to have friction somewhere in the system. It's the sort of challenge that I quite relish, but then I have been analysing mechanisms a bit like this for the best part of 50 years (usually when they are not working properly because of friction). Even so, my starting point now would be to look at adapting a commercial product.

[nothanks]

Clearance isn't an issue; the hatch isn't at the centre of the span but there's no shortage of space above it. I've been looking at commercial mechanisms and spare parts, but mine will be heavier (mostly because of the door and because I want to make the steps as wide as possible). There seem to be lots of spring design websites but I've no idea how to estimate the required spring force. The answer might be to use off-the-peg bits and to keep adding springs until the weight is roughly balanced, but the loads on the attachments might get worrisome. With all the other jobs in progress I'm not exactly wanting another, but it's a problem that needs solving and it's useful to gather info.

[Michael Chare]

I have a loft ladder which is similar to the Youngman's 3 part one that you can find with google. There are no springs. To raise the ladder you push up the bottom two sections so that the bottoms are level with the bottom of the top section. You then use a pole to push (tip on the hinge) all three sections up into the loft where their weight keeps them level with the loft floor. The pole is needed to gently pull them down.

[George Miles]

[tabbypurr]

If you're not short of headroom just use a 1 piece ladder with weight on a pulley.

When using multisections the pulley mech doesn't need to balance it, just needs to keep it within workable limits.

NT

[nothanks]

That's an interesting idea. A 1-piece ladder mounted to the trapdoor on some sort of rollers so the ladder pushes-up until the bottom clears the edge of the door and latches in place, the top of the ladder then drops down onto the attic floor as the door is closed. The trapdoor needs to be hinged at ceiling level so, with 8" joists, the ladder would need to be held at least 9" above the door to be able to lie flat on the floor. At the moment I can't see how a pulley and counterweight could be made to work when the top of the ladder would be swinging through a large arc, but it might be possible to use a long spring, rope and pulley between somewhere on the door and somewhere on the ladder.

[tabbypurr]

I think you may be overthinking this counterweight thing. Mine has no counterweight or spring and is just fine. If you make one that's awkwardly heavy, a partial counterweight should be enough. A 1 storey ladder is not normally overly heavy.

NT

[nothanks]

I can accept that for a regular ladder, but my thoughts have developed a bit. I want more of a pull-down staircase than a regular ladder, with treads instead of dowels, and also for the ladder to be wider than the standard 400mm - maybe 550 wide. If a regular wooden ladder is about

10kg I'd guess I'd be heading more towards 25kg. When the ladder is in the "up" position the top part should partly counterbalance the door and ladder so all I need is a means of taking-out the rest of the load (up'n'over garage door thingy?) and a means of reducing the effort of sliding the ladder from the down to the up position. I also need a box of tuits!

[tabbypurr]

Well I tried.

[nothanks]

I'm grateful for making me realise that a one-piece sliding ladder could be a better solution than a z-fold.