For reasons involving space, acoustics and the increasing need for a decent home office I've recently converted my loft into a decent sized domestic environment. I live in a typical semi-detached property built in the late '50s and the project involved squaring the walls at the gable and the rear of the property.
At this point the main building modifications are complete but I opted to do the insulation, internal plasterboarding and flooring myself. To give an idea of the space thus far, here is the view towards the party wall (the OSB boards on the right are covering the window apertures as there will be a delay of some weeks before they are ready) ...
... and here is the view looking the other way from that wall:
The picture above shows where the stairs come up. There will be a stud wall box over the stairs (at a height of about 80cm from the floor) and there will be a floor-to-ceiling enclosure to allow for a door to be fitted at the top of the stairs such that when it's opened it faces the party wall at the other end.
The supporting stud wall to the right of the stairs denotes a storage area under the eaves which I will be enclosing fully with an access door into it just to the left of the velux windows.
Much as it would be an interesting project to make this as robustly commercial grade in terms of music studio use as I can, my objectives are somewhat more domestic.
My main considerations are:
- The space is to be used for music and a home office
- The view out of the windows is important
- I create mainly electronic music but would like to do a bit of acoustic stuff now and again
- Accurate mixing is more important than accurate acoustic recording
- Soundproofing is much less of a priority than acoustic treatment (I don't work at high volumes)
- Notwithstanding the above I want to minimise downward noise from activity in the space to the bedrooms below
- Acoustic treatment is something I'll focus on more later - for now I'm mainly thinking about the structure
I've got enough Rockwool RW3 in house up there to insulate the space between the floor joists. The skin on the floor is 22mm flooring-grade tongue and groove chipboard, currently sitting there unfixed. I think it would be wise to install some form of isolation on the joists beneath the board and considered neoprene (which is an option) but also found Green Glue Joist Tape which looks an interesting option. Any thoughts on that?
The joists are pretty robust. They are at 300mm (or so) centres and consist of pairs of 2x4 timbers. I've not got a decent pic of them yet but here're a couple of the room while it was being constructed which give an idea:
There is also going to be a storage area under the eaves along the length of the room, with a couple of access points as shown here:
Due to building regs I'm limited in the options for insulation on the outer walls and ceiling (it has to be breathable and allow internal airflow across the top of the building) and will be installing various thicknesses of celotex in the ceiling, skeiling and walls which has good thermal properties but will be of little-to-no acoustic value. The plans also require an internal skin of alumi-flex. However, there will be thick acoustic plasterboard on all the walls as well as the ceiling (the exact specs escape me right now but it was 20mm or thereabouts - I'll confirm later).
Electrician is coming next week (covid permitting) to install the lightning and spec up (and possibly start to install) about 30 power sockets. Also getting a new consumer board downstairs. He's already routed a bunch of cable with extra thick core up to the new space in preperation. I've spoken to him about the need to minimise the risk of ground loops and he's made some positive noises about that; we're going to discuss further when he gets here.
The main windows are floor-to-ceiling. Each is 2.1m wide and 1.8m high with a safety bar 80cm up. They are double glazed but the inner side consists of 6.8mm thick laminated glass with a transparent acoustic layer somewhere in the middle (my window supplier already knows my requirements well and did the rest of the house earlier this year!)
That's where I'm at right now. I'm basically trying to get the space usable and make sensible construction decisions with a view to adding acoustic treatment later.
Any advice on things I can be thinking about/talking to contractors about in the meantime to help achieve that goal are welcome!