The timber frame which holds the insulation is well underway. The frame was designed to accomodate 350mm Warmcel insulation on the outside of the original concrete walls.
As we’ve become accustomed to, there were some challenges with this too! In the design stage, Clive our architect worked with Teploe Ties to design a brand new type of fixing so we could attach from the concrete wall to the timber frame. There is a photo in the gallery below.
At the rear of the building, the wall bows out where the concrete wall meets the concrete bank of the river, this means that the steel fixings have to be shaped on site one by one. The frame was designed with the fixings at 600 centres, but the concrete we need to drill into at 600 centres ranges from solid pebbles to empty voids between pebbles. We’ve consulted the structural engineer and managed to overcome this problem to get the frame up.
The asbestos shuttering on the houses formed horizontal channels all around, so these have been be filled in to prevent air circulation. We then fixed OSB onto the surface using grip fill and mechanical fixings. The grip fill was applied in a grid pattern so there are no large pockets of air behind the boards. Ideally the whole OSB should be covered, but we decided this was a suitable compromise given time and resources available. The OSB joints will then be taped.
The timber frame is then fixed onto the outside of this. Because there is asbestos in the walls, the drilling will be accompanied with a hoover. Dust is also minimised because the OSB is already fixed on the outside.
The scaffolding has been adjusted numerous times throughout the build, currently it is far enough away from the external walls to allow the timber frame to be built up between. This meant our H&S inspector requested we issue full arrest harnesses, and you can see the guys wearing them in the photo as they fix the OSB.
The window boxes need to be made specifically for each window. Elliot, our carpenter, has measured all the windows and made up boxes for each one individually. Then the boxes will be trimmed in situ as the original walls are slightly irregular.
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