I am now putting in the finished flooring on top of the chipboard sheets that sit on top of the joists. I have decided to go for scaffold planks. The problem with most conventional flooring products is that they all look too perfect (as well as being pretty expensive if you want solid wood as distinct from a laminate). For a project such as ours you need to have a floor that looks suitably rustic – and scaffold boards do just that.
Scaffolding Direct sells new, unbanded boards in various lengths, which work out at a cost at around £14 per square metre. This will give you a chunky 38mm, 23cm wide, board. The boards will obviously need to be sanded and finished, but the look is so much more solid and attractive. Interestingly, the price of new boards is about the same as recycled ones and since both would need to be sanded and the used ones are more likely to be damaged, as well as having bands on the end that would need to be removed, buying new seemed a better option.
I am nailing them down, rather than screwing them, because I think boards like this need to have visible nails to look suitably authentic. I would like to have used cut nails, but this won’t grip into the chipboard, so I am using good old ringshank nails. I got boards in lengths of 2.4m so as to get a good number of joins, since I think this also is a better look. I expect to get a little shrinkage over time, but this shouldn’t be a problem because big boards like this look better (more authentic if I may say that again) with slight gaps between them.
I have spent the last couple of weeks putting in all the flooring and ceiling joists as well as the actual flooring in the living area. The flooring in the bedroom / bathroom area will have to await putting in the drains and be coordinated with creating the studwork for the bathrooms. This will happen next Thursday, under the direction and assistance of brother-in-law Nick – who is a builder and therefore knows about these things.
The one piece of advice worth passing on for the non-builder, concerns the slight absurdity of the fact that sheeting products such as floor sheets are generally available in imperial sizes (i.e. 4×8 foot whic is approx. 1220mm x 2440mm) whereas plans always specify metric gaps – such as 400mm or 600mm. However, this should not lead you to space your joists at imperial-friendly gaps (e.g. 610mm) because, if you are using tongue-and-groove flooring sheets these are 8ft long but this includes a 10mm tongue – so the actual length of the sheet is less, making it sit perfectly on joists at metric 600mm spacing.
I have also become an even greater fan of expanding foam, especially the type with the attachable gun, because this makes it possibe to do ‘precision welds’ along joins (see picture) rather than the rather messy results you get with the conventional single use cans. No exactly natural building, but you could say eco-friendly in terms of creating good airtight seals.
Looking back over my posts I saw that last year’s task between Christmas and New Year was the construction of the roof trusses. This year’s has been putting in the suspended timber floor.
The I Beams arrived just before Christmas. I sourced them from Pasquills, who were very helpful – I just just sent them a copy of my plans and they produced a design which specified the size and spacing of beams required for each span (220x65mm in the most part with some chunkier 220x97mm to support water tanks in the attic space) and supplied all the necessary hangers. A 220mm beam will also allow the 200mm of insulation required to get a U-value for the floor of 0.18
Thus far I have put all the beams in place in one half of the building, including putting down a weed-proof membrane and layer of gravel, and completed the isulation in half of this. The insulation is carried on a 4mm ply sheet which is glued and nailed into the bottom flange of the beams. I also decided to put the ever-useful expanding foam to seal the gaps at the ends of each run and the join between the ply sheets – just to improve the air-seal. Straw Works don’t specify this in their plans, but I expect this is because they don’t like expanding foam and there isn’t really a natural alternative.
I would estimate that time required to put in each section (hanging a beam, putting in noggins at the ends, cutting and putting in the ply and then laying the insulation) is about 45 mins. I haven’t put the chipboard flooring sheets in yet, since they will lie crossways to the beams, thus all the beams plus insulation need to be in place before doing this.