So with the floor down, the internal partitions can start to take shape, starting with those that define the shape and size of the future stair. With these in place the final detailed design and fabrication of the stair can begin...!
Concrete pours are always stressful and this was no exception, although we got a nice technical rep. in to support us with the Self Compacting Concrete (ie self-levelling - magic!) as a promotional freebie, the lorry was late and almost got stuck the wrong side of a parked car... But once cured the concrete will form a solid, flood resisting floor that will add to the thermal mass of the building, smoothing temperature fluctuations. The concrete came with steel fibre reinforcement (chopped up wires) that meant we didn't need a reinforcing steel mesh, saving time, money and aggravation (and injuries!).
So for some time I've been worrying about moisture within the ply sheathing. Water got in before the final roof sheeting went on and because the foil faced insulation on the outside won't allow moisture vapour to pass through then any water within the ply has to evaporate to inside the building. So whenever possible all the doors and windows are open to get a good drying breeze moving through. I had in mind that I was looking to get the moisture content down to around 14%, which is where fully seasoned wood will settle, and over the last few weeks I've been prodding around with a moisture meter to see how close we are (see pic.). The solid timber studs are mostly 14-15%, possibly because they're exposed on three sides, but the ply has been 16-19% with odd patches between 20 and 26%. So I put in a call to the TRADA technical helpline (www.trada.org.uk), a trade body who offer free advice about timber. Apparently the 'magic number' is 20% - above that timber is vulnerable to fungal and insect attack, below that is seen to be OK. So that was a green light to crack on and fit the insulation between the purlins... for the odd patches where moisture is still above 20% I'll use an electric fan to speed up the air movement...
A black cord hoody for a house! Roofing sheets nearing completion on the west, rooflights fully fitted along with recessed flashings to reduce their visual impact. I really like the look of the Onduline cladding, especially in strong sunlight as shown here. Hoping to complete the east roof face later this week then I can't wait to see the walls completed. Once the roof's done we should be pretty much weathertight, which will allow the plywood to fully dry out - at that point insulating and lining the inside can begin....
Work on the roof has moved on, with the final layers of external insulation now laid, and corrugated sheets starting to go up. Hoping that the replacement rooflights will arrive in the next day or two or this will start to cause a hold up. Very satisfying to see the final cladding going up - I just want to see it all up now so we can really say that the structure is weathertight.
2 rooflights fitted (2 still to go). Unfortunately I ordered 2 at the wrong size - biggest cock-up so far. 200mm too tall and I only worked it out after I'd opened a box, so return not possible - want to buy a rooflight anyone? Because they're snug between the purlins there's no chance of making them fit, so one is going back for a hefty (25%) restocking fee and 2 replacements are due any day now. Manufacturer is Keylite - seem to be competitively priced compared to Velux with a better U-value (1.0) on the standard range. Fitting was straightforward once we'd deciphered the international pictogram instructions...!
Mike Hawkins is a co-op member and is responsible for the design and management of the build. He'll also live in it when its finished - hooray! He teaches future architects at Leicester DeMontfort and Birmingham City universities.