I spent the majority of Saturday on the studio so I was able to make reasonable progress.
For the most part it was time spent finishing off the ceiling cloud. I mentioned earlier that I found that the mineral wool supported itself well between 60 cm pitched framing so I had to add central battens to divide the central 120 cm into two 60 cm gaps. I needed to make this in two separate sections and screw them individually either side of the opening which will most likely be filled with plasterboard to allow for lighting.
Once the central framing was done I simply had to get out the bread knife and attack the mineral wool! It's always quite a satisfying job despite the resulting itchiness. Anyway, it didn't take long to fill the framing and I have now almost covered the entire ceiling with 100 mm (4") of mineral wool (cloud). I'm going to cover the cloud at a later date in case I need to make any adjustments when I come to start testing the room and this is something I'm really started to consider now.
Here's a photo showing the cloud:
You can probably see the cloud doesn't finish flush with the side of the room and I have been considering a way of making use of this void. I'll need to be getting some form of permanent lighting in place pretty soon and I'm thinking about making use of the void at the edges for some concealed wall lights. I want to make the room as low energy as possible and LED would seem to be the obvious choice. What I'm thinking at the moment is to buy some LED strips that can be cut to length and located to the sides of the cloud at 45 degrees thus bouncing the light off of the wall. Still early stages here but they are very cheap and run off 12v transformers and are extremely low energy - more research and although they won't provide glaring daylight for reading they may well give a nice ambience to the room...
I then gave the room a good clean and vac as there was a fair amount of mineral wool particles and general dust hanging about. Next job: give the walls a lick of paint.
Before painting I had some more filling and sanding to do and so I spent the rest of Saturday going over any indentations, holes & gaps. I did a bit more sanding on Sunday before staring to paint. I have a big tub of trade satin white paint in the garage and this was ideal watered down as a mist coat over the plasterboard. Starting to look better already though I think I'll need to go over with the filler again before another coat as a few dents are highlighted with the paint.
A couple of photos:
As mentioned earlier I'm starting to consider the acoustics of the room now and what is obvious and it has been noticeable for a long time is the flutter echo in here. Though that is pretty easy to deal with some mid - high frequency absorption I need to get my head into Rod Gervais' book 'Home Recording Studio - Build It Like the Pros'. Probably the first rule in there is to try and steer clear of small rooms - exactly what I have here!