Flooring a loft with chipboard loft boards

[Tricky Dicky]

I need to extend the floored area of my loft. The loft consists of trusses supporting the roof which is quite a low pitch so you cannot stand up in it. Previously I attached 3 X 2 cross members to the trusses 300mm above ceiling height so not to compress the insulation. I then used loft boards screwed to the cross members to form the floor. Owing to the variable spacing of the trusses to get the boards short edges to rest on the cross members meant a lot of measuring and cutting wasting a lot of material in the process not to mention time. This time I am thinking of avoiding the cutting so I am thinking of staggering the boards which will mean most of the short ends will end up in space and hoping the T&G of the adjacent boards will provide the support. The flooring is only to provide crawl space whilst I get some wiring done. Anyone done something similar and does it provide adequate support for an overweight not so agile OAP to crawl around and work in?

Richard

[Andy Burns]

With "weetabix" loft boards? Not a chance.

[tabbypurr]

T&G has very flimsy tongues & grooves.

NT

[John Rumm]

You could just glue the T&G at the ends of the board.

Alternatively, rather than mess about cutting the boards to length, just slap a nogging in between any pair of joists where you have an unsupported end. A bit of 4x2 on its side would give plenty of extra support to the cut ends even though it would not be full width.

[Gareth's was W7 now W10 Downst]

Interestingly, AIUI, the word Lesbian is no longer politically correct and such ladies must now be referred to as Floorboard Merchants

All tongued and grooved!

[Andrew]

I've done exactly the same, but used 2*2 rails, 3.6 metres long, at 90 degrees to the trusses and elevated above them with home-made extenders cut from scrap 1 inch plywood, 6 inches wide and a 2*2 notch that the rail sits in, while the bottom of the extenders are glued and screwed to the trusses.

I managed to get a whole load of scrap 15mm MDF from a B&Q refurb each 900 * 600 mm. (used to have heating components screwed onto them for display). Cutting around the zig-zag truss components was tricky and time consuming but possible with various packers.

As long as the edges of every flooring section are supported and fixed, theer should be no problem.

If I was doing it again I would use 15mm OSB because that is not as heavy as MDF.

You ought to consider the illumination up there. If you extend off an RCD extended lighting circuit and manage to trip the thing while up there, while in an awkward position, how will you extricate yourself ?.

[Andrew]

Loftboards are particularly nasty and fragile. Use proper

8*2 t&g flooring, which I managed to get up into my 1976 loft with trusses and a 37 degree pitch to have a storage section around the loft hatch, then years later used 2nd hand 18mm mdf panels on support rails to allow a 300mm insulation depth.

[PeterC]

I used P5 chipboard. It has a very hard top face (blue, green? - CBA to check). It's quite water resistant (got an unexpected shower on a 'fine' day, enough to trickle of the stack, but not only was the top face OK but also the exposed T&Gs. I tried an off-cut, about foot wide IIRC across a 16" gap and it took my

85kg or so quite happily. Also cut off the bottom of the groove and all of the thinnest part of the tongue so that it's fairly easy to lift a sheet. It's solid to walk on, even carrying a heavy item.

[George Miles]

[Tricky Dicky]

Just to clarify, the roof pitch is a mere 22° so with the floor in place there is barely room to kneel at the apex. As I mentioned before the flooring is merely to make it safe to work in the loft and only a strip down the centre less than 2m wide is to be floored. Once the wiring is done I have no intention of using the loft for storage having a 40sqm garage which is more than adequate.

Richard