I want to make a hole in a plasterboard ceiling to get access to the roof-space in my one-storey cottage. I have found that the joists are 1 foot apart, and am thinking of making the hole a little under 2 feet square, which would mean cutting one joist. and putting 2 cross-pieces to hold the joist.
Is this a job I can do myself? Or should I get a builder. I'm reasonably handy.
Any advice or suggestions gratefully received.
A builder is not better than you, he's just done it before.
Round here there are firms who come and fit loft ladders and hatches. Last time I looked it really wasn't worth doing it yourself
Timothy Murphy coughed up some electrons that declared:
**** As always with free advice on USENET, please wait around for a bit to see if there's are any refinements on what I'm about to write and make sure no-one disagrees fundamentally with what's below. ****Well - it sounds like a pretty standard loft-hatch arrangement.
I assume the joists are only holding the ceiling up? And are 4x2" or vaguely thereabouts?
Personally (and I'm going by what I've seen, not done myself), I'd:
1) Prop the ceiling joist from below, the one that you're going to cut, at both sides of the cut (unless one bit will be so short and near the supporting wall that's it's obviously not worth bothering because you are sure the ceiling will hold it - I'm talking a couple of feet or less long)2) Cut the joist and remove the redundant bit in the middle.
3) Arrange two bits of 2x4" (or whatever the size of the joists are) across the ends of the cuts like this (pieces ac and bd):a b =============================== uncut | | | | ==========|e f|=========== cut | | | | =============================== uncut c d
Fix new wood ac and bd at all points so that the joints can take vertical loads. Often this was done by banging 4" nails into the side of one piece through the end of the bit it was being fixed to.
This is how all the openings I've seen (not many) have been done.
*** I guess this is exactly what you were thinking of doing, based on your description? ***I'm not very keen on structural things (I like wet things and sparky things, but not together!) and I would tackle a job like this, as long I was absolutely sure that:
a) the joist wasn't doing anything else other than supporting the ceiling (do you see any cross braces to purlins or anything like that?)
b) I'd propped it well - acro-props are dirt cheap to hire and you'd need two, with a 4 offcuts of ply or plank to acts as pads top and bottom to protect the floor and ceiling finish.
------
You might get away with cutting two joists for a decent sized hatch, but I wouldn't want to commit to saying it's definitely OK it as I can't see your ceiling.
HTH
Tim
Aren't joists normally under tension loads, because they're preventing the eaves from being pushed outwards by the pitched roof?
Huge coughed up some electrons that declared:
That may be true. I'd assumed one could get away with the odd one or two being cut as the affected roof rafters would be supported from spreading by their neighbours (via the purlins and the numerous tile battens) and the cut joists may pick up lenghtways support from their neighbours in similar nefarious ways.
I'd be interested if there is a "proper" answer to this.
Cheers
Tim
Me too. When I put in a second loft hatch (*), I didn't cut any joists, which means the hatch is a little narrow, although serviceable.
(* The first one is right under the water tanks, and I cannot get into the loft via it, although the plumbers 17 y/o mate could. He's about as many stone lighter than me as decades younger....)
I'd go along with TS's advice and disclaimers, other than to say that depending on the size of the ceiling joists, it's quite likely that you wouldn't need acrows; unless they are stonking great heavy joists I would expect the plasterboard to hold them up while you're doing the work. If you *were* concerened, you could poke your head up through the new hole in the ceiling, screw down a perpendicular batten across the top of the joist you're cutting and its two neighbours, which will take the weight temporarily.
David
Mmm. In a truss, yes. with no load above the ceiling apart from end pinned trusses.
But there are other ways to make a roof..warren bracing and purlins etc.
Purlins put them into compression, by and large, and a warren truss will introduce bending moments. As will any loft load.
There is, but its entirely dependent on the exact roof layout.
But there is normally bags of redundancy, so go ahead and do it.
If you're going to do that brace the ends of the cut joist to the roof suppoting beams metal ties, as when you climb into the loft space pressure is put on the surrounding cutout loft hole because theres nothing to give it support.
I did a similar thing to get access to the roofspace over my garage. I first chopped half into the one joist that was going to need to be cut, at the two places where the cut piece was going to be removed from. I then took the two pieces of wood (same X by Y size as the joists) and cut them the right length to fit between the two adjacent joists, and similarly chopped in. The cut pieces were then fitted in place, and end nailed to the adjacent joists. The half-lap joint formed where the chop outs met, was glued and screwed, and then the joist piece was sawn out. I finally made sure that it was all strong and was not going to suffer sagging when a person's weight went on it, by screwing down some ply around the opening, to form a platform to stand on when you get up there. As others have said, I think that there is enough redundancy in the roof construction for it not to be a problem, but the way I did it at least ensured that there could not be any 'spread' when the piece was cut out, as what was to become the cut ends, was already tied to the adjacent joists
Arfa
That's what I'd do, no need for any props. The above temporary crosspiece has the advantage that weight or force inadvertantly applied to the unsupported PB wont bust a larger area of ceiling. Plus its less wood use than a vertical timber prop - and at 2' you'd probably find something from the scrap pile.
If the access were only very occasionally required, ie just to check if repair is ever needed, I'd consider not bothering with the joist operation. A foot is hardly generous but it is enterable/exitable.
NT
I wouldn't make the hole square... it can be longerlong the direction of the joists, making it easier to get in ind out...
and, as someone suggested, can you squeeze between the existing joists?
I dont know if i can get through a foot wide...
depends on how high the roofspace above where you put the hole is, I guess the more height above it the better, and a rope hanging down to help pull yourself up...
[g]
Thanks to all for the generous advice. I think I will take the coward's way out, and leave the job to a builder.
Incidentally, the reason for the project is that a professional insulation expert refused to get up through the present access hole, which is admittedly very awkward to climb through. The roof space is just 50cm high. The expert said that he employs several Polish men who will install insulation for him almost anywhere, but that this was too much even for them.
IMLE its a good deal easier to climb into narrow gaps like that from atop a flat surface than from a ladder. So you dont need the ladder either.
NT
IMLE its a good deal easier to climb into narrow gaps like that from atop a flat surface than from a ladder. So you dont need the ladder either.
NT
... and narrow entrances are easier if a decent width in the other direction due to body movement.
NT
HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.