Hi All I've asked various questions here on aspects of a recent project to insulate and board my loft. I thought I'd report back now that it's mostly done.
- I originally thought of putting cross-joists in, celeotex sheets between these joists, and then boarding over those joists. In the end I was persuaded to forget the cross-joists, put the celotex down over the existing joists, and board over the top of the celotex. I was glad I did that - the cross-joisting would have been quite an effort and I don't think I'd have liked to lose the extra height anyway (we have a hipped roof).
- I didn't want to use the T&G chipboard panels that the sheds sell and eventually went for 18mm OSB. Again, I'm pleased I did. I did try to get
18mm T&G OSB - Wickes sell it but won't cut it. Given that I was boarding over Celotex, with a bit of give in it, the T&G might have been good for a little extra stability ... but on the other hand it might have ended up putting strain on the T&G, causing the ends to fracture - just the sort of thing I hated with the chipboard panels.- so anyway, I bought a few sheets of 8 by 4 by 60mm Celetoex from seconds&co, and cut them up into widths 660mm wide. These just go through the loft hatch, and three side by side fit nicely either side of the main cross-joist. I used an old bread knife to cut the Celotex, as suggested here
- tedious but works well. I used a padsaw with an old hacksaw blade for trimming when up in the loft - quicker but makes more mess.
- I got the 8ft by 4ft OSB cut into fours, ie. 4ft by 2ft. This was deliberately a different with than the Celotex in order to stagger the ends. I also cut one of the OSB panels in half so that they sould be staggered longitudinally.
- I bought myself a couple of toys to assuage all the effort I was going to... A Makita TDS220 impact driver, as recommended here, and a Bosch PFM180 multi-tool. I ran an extension lead up into the loft to power an electric drill for drilling the OSB, a Henry Vacuum cleaner, and the Bosch PFM180. I spent £15 on a couple of 2ft Fluorescent fittings from Wickes and fitted them the week before - very glad I did. A Bulkhead lamp wandering around also came in handy.
- I didn't skimp on the PPE, and I'm very glad I didn't. We already had some glass fibre insulation put down, and my original idea was to put another layer over the top of that, bringing it up to the top of the joists. However (a) we had a rat problem a while ago, and I wasn't going to put my nice new insulation down over that disgusting mess. Also, it's clear that g/fibre insulation has improved a lot over the years (in terms of 'loft'), and that the old stuff was going to do comparatively little. The worst part by far of the job was getting the old f/glass up and out. I brought a 1m3 'builders bag' up into the loft and filled that as often as I can. I wore a paper suit, kneepads, a £20 respirator, gloves and a head torch. I also took the Henry into the loft to clean up the droppings and general crud up after I'd removed the old insulation from between each pair of joists. Probably the hardest bit of the hole job was actually getting rid of the old fibreglass, hardboard, bits of carpet and miscellanous nailed-down down bits of board that were up there in the first place and which got in the way of what I wanted to do.
- I used some 5x100m (I think) screws from Screwfix for screwing the OSB panels down, through the Celotex and into the existing joists. They were some fancy range with a varying thread; mainly I used them because they came in the size I wanted!
- The Makita Impact driver worked well - I'm sure it was well under-used for this job. I probably used about 100 screws (only lightly screwed down each board) and still on my first tip. As others have mentioned the LED light is more useful than I imagined. Though I doubt I'll be doing much drilling in such awkward conditions for a while.
- I ended up using the Bosch PFM180 multitool, which I bought partlya as a 'treat' because it was on offer at B&Q, to notch the OSB panels where they butted up against a joist or something. It worked well for this, but I'm not sure what I think of it ... a bit of a bodgers tool maybe. Not to say I'm above a bit of bodging, but... Anyway, we'll see what use I find for it in the longer term.
- All in all I'm quite pleased with the results. By design I've only done about two-thirds of the loft so far. The whole point was to get some surface area to store some stuff up there. I'll probably do the rest next year, now I know what I'm letting myself in for. I probably haven't saved any money over getting someone to do it for me, and I had aching knees and back for a while, but I've 'won' a couple of toys from it, and I wouldn't have got it done the way I wanted it without a fair bit more expense.
I'd definitely recommend spending a fair bit of time planning things like what size to cut the panels, how to stagger them, what tools you'll need and in what order etc., if you're doing something like this yourself.
So - a project 'mostly completed' - does it get any better than that! Thanks for the various bits of advice I received on this from the august members of this fine forum.
Cheers Jon N