First a few small jobs:
1. I had noticed that there was some flex in the front wall and although once the drywall is screwed in this would be reduced I decided to effectively tie the top plate to the joist, which is only about an 1" or so from the corner. I took an off-cut timber (tie-block)about 20cm long and chiselled a groove 32mm wide along its length at 7 degrees. This gave a profile that would allow me to screw it to the corner joist, locating on the 32mm square battens for the ceiling drywall recess. I then had to unscrew the joist, glue and screw the piece to the joist (batten) centrally then re-screw the joist in place and finally screw from underneath the wall top plate into the new tie-block. Wow, what a difference! Very solid now...I even gave it a kick!! >> Photo - Front Wall Tie-block<<
2. There were still a couple of gaps at the top of the wall on the left hand side between the roof and the wall top timbers. I had already filled the larger gaps with strips of timber and glued and filled with gripfill ages ago. This was pretty straight forward using a couple of off-cuts about 50mm long. I no-nailed and screwed these in place blocking the holes. I then filled all around to close up any small gaps.
3. To allow for the cabling between the PC (in the airlock) and the desk I needed additional space. As mentioned earlier, some cables (CAT5, Power etc) can be run underneath the stud-work through my channels cut under the sole plate. However the display cables with moulded ends need to be fed over the sole plate and down into the floor. To allow the cables to pass down I chiselled out a channel at the front (inside the room) of the sole plate and routed rads on the top corners to soften for the cable bends.
>> Photo - Sole Plate Cable Channel <<
With those jobs done I'm pretty well clear to continue the mineral wool filling...well apart for one other thing, but nothing too drastic: basically, I need to add some timber to the stud-work near the air intake to allow connection of the silencer box in that corner. But for the moment I am going to crack on filling the ceiling.
Having thought about my method of filling the ceiling I worked out that cutting a slab of RockSilk (1200x600x100mm) along its length creating a piece 1200x300x100mm. The void above the ceiling drywall works out about 300mm so these pieces cut to suit will fit quite nicely into the void on their edges (100mm side), pretty much filling the entire cavity. Uses a lot of mineral wool in the process but I am a little concerned with the transmission through the roof so I think this will at least be the most I can do.
First of all, because the joist cross section is effectively a squashed up crucifix upside down - it has quite a tricky shape. I made a small template with that profile to help cutting the pieces. I started off by cutting the complete length (1200mm) with the joist profiles at the bottom. These bridged two joist. Although it worked OK I figured that smaller pieces would be a lot easier to fit in place and after a few sections I abandoned that larger sections in favour of filling between two joists at a time.
>>photos<<