With the 7x2in joists all cut to length, ends re-sealed and ready to fall in to place, my next job was to set out the positioning and spacings for each of the sixteen hangers (eight on either side) and then, to fit them in to place. Below, you can see a mock-up of what I needed to achieve, where the joist must sit 32mm (1¼in) higher than the wall plates, in order to clear the existing truss-frame by a good 5mm, which had already begun to deflect where I’ve previously used it, in appropriately, to store goods (it’s only 4in/100mm deep and is riddled with woodworm, you see).
If you look closely at that first photo, you’ll see that one of these scraps has been trimmed to a depth of 143mm (32mm less than 175mm). I later used this same block, temporarily screwed in place, to set each hanger in its correct position, with regards to the height of each joist needing to be higher than the wall plates.
In this photo from 2009, you can just about see my former storage solution, with a long length of 4x2in and an old light fitting spanning the distance between the two 4x2in joists!
Now, the joist at the far end, closest to the rear wall, was going to be 50mm or 2in away from that wall (though, this distance is actually dictated by the width of one leaf of a joist hanger). Moving back towards the front of the floor and, I also wanted to bolt one of the 7x2in joists directly to the existing truss – this was also notched accordingly to sit over the blockwork pillars at either end, which carry the vertical load of the truss and the roof itself, down to the floor.
…Okay, so I over-cut the length of each notch by about 10mm each end!! 😳 It doesn’t matter too much as this joist is, again, bolted to the existing truss plus, there’ s more than half its overall thickness sitting on top of the blockwork. Still, to be on the safe side, I’ll fit a a pair of folding wedges, later, to seal off each gap.
If you’re waiting to read more on these new Metabo 10.8v Powermaxx 12 drills I bought before Christmas then, I’d been asked to write a gust blog post over on the Toolstop Blog, which I’m aiming to get done within the next week.
Whenever you’re fitting joists, whether it’s for a floor or for a roof, it’s advisable to sight down each length and note where the ‘camber’ or curve is on each edge (I marked mine with an arrow, as above). You should then ensure that all joists are set out in the same manner. I prefer to fit mine with the convex edge pointing upwards but, there’s also a good case for fitting them so that it looks like they’re “sagging” downwards… In a situation like this though, where the floor is unlikely to be walked on (I don’t know anyone less than 3ft tall…), it’s not critical which way they go. This floor is primarily for storage, after all.
Fixing the hangers was fairly straight-forward at first. Several builder’s merchants recommended these Simpson Strong-Ties to me, where I am essentially fixing timber joists to timber wall plates. Twist nails were uses to secure the face of each hanger to the walls, ensuring compliance with the specification, with regards to the minimum number of fixings in each part of the hangers (four in the top, eight on the face and four in to the joist). I’m not saying that it was easy banging those small nails in to masonry, though!! 😉 Where the roofing sheets (which I didn’t want to remove!) made the angle too acute for me to comfortably hammer a nail in to the top of each hanger, I instead reached for my Powermaxx 12 drill and fitted the angle driver attachment – which arrived just in time, thanks to both Toolstop and Metabo! – which allowed me to drive four 1inx6 stainless steel screws in for a secure fixing. Where the straps were too long and could not reach down behind the back of the wall plates with the corrugated roof sheets in place, I opted to bend them back towards the joists. This is better than simply cutting them off, which would, of course, expose portions of the steel that hasn’t been galvanised and could lead to premature failure of each hanger.
You can also see, in the photo above, where I’ve already begun draught-proofing around the eaves with a can of expanding foam. For future reference though, I must stress that these cans should ideally be used and thrown away on the same day. Otherwise – as I discovered – despite all your best efforts at cleaning (see foam eater), the foam will still go-off and cure inside the nozzle, which renders only capable of producing a mere dribble of foam, at best! I’ve been advised to try the gun-grade expanding foam instead, which apparently can be used even one-week after the first application.
If I wasn’t too busy wrestling with each 3m length as I tried to fit each one in to position, I’d have taken an action-shot that would tell you all you need to know about fitting joists in to a space where the roof’s already covered. You see, on new-builds and renovation work where the roof is still to be done, you can attach all the hangers to both wall plates and each joist will simply drop in to place. This wasn’t practical in my situation and, as according to the Building Regulations, a joist depth of 175mm was the minimum I could get away with to cover a 3m span. So, after fixing all the hangers down one wall, on the opposite side, I only fixed one-half of each hanger. By binding the other half out of the way, I could drop a joist in at one end and swing it round in to the other, before securing the second-half of each hanger. It worked very well; I just wish I’d taken the time to grab a photo but, my arms were very tired for the next couple of days!
All the joists were in place before the end of my first full-day. I do wish I’d allowed a couple of millimetres on the length of each one though, as it only made the task of swinging each one in to position that bit more difficult – lots of hammer-action and swearing was required!! Leaving any high-up shelves in place does help when you’re doing a job like this and are working on your own at the same time. I did make sure to clear them all off first, though! 😉 Sighting across the tops revealed that everything was surprisingly parallel and level. Alright, so, spirit level did show that they weren’t all perfect but, I should be able to shim up or plane-down the high-spots, if at all necessary.
At the end of Day 2 (my first full day on this job), it was nice to have somewhere to store these other long lengths of wood and, at the same time, to be able to try the new floor out for size! 😀 I’ve already discovered that, for anything over 3m/10ft in length, I need to close the up-and-over door behind myself as I lift each length up. Otherwise, there isn’t enough clearance and I just end up trying to put a hole in the roof!
Thanks for reading.