AlvaMusicProductions wrote:Hi Paul,
Thank you for the reply and the great thread!
As for the slab, I think I forgot to mention it's not actually on grade, it's on the first floor (it's the "attic" if you will, of an old farmhouse) and right next to it lives my family, so I'd have to really isolate it, at least I think I do. What does that tell me about the resonance frequency situation, would a floating floor work better or make it worse if I'm on the first floor of the building?
I already have some ideas a ventilation system, maybe one or two of these (
https://www.lueftungsmarkt.de/helios-zl ... wandeinbau) build into the walls of the room, connected to a large (16cm diameter) tube, which goes to the outside through the outer roof of the building. There is also a heating unit that can go in-between the tubes and the ventilator, so that the air gets heated up. Still, just an idea, if you have more advice on ventilation and air conditioning please let me know!
Cheers,
Mika
My bad - you did mention it was an attic but I obviously forgot that part while I was replying. So how is the floor constructed currently?
This does complicate the build since you'll need to find out how much weight the existing floor can take, for dead and live loads. It is also very, very difficult to isolate a space with a room below it effectively, this is because your outer leaf (your existing building) is attached to the rest of the house. The walls connect to the rooms below, so even if you isolate the floor and build a new inner room, the outer room will still transmit vibration throughout the rest of the house. So the best you can do is a new, very dense inner room, but accepting that your outer leaf will be compromised. So yes, in your case a floating floor will be needed. How you build the floating floor depends on a few factors...
I think I would get a structural engineer involved and come up with a plan of how you can safely build a decoupled free standing room within your existing space - I do not know the regulations in your country for carrying out such a build.
I also think you need to accept that you will only be able to gain so much isolation - it will not be perfectly quiet in the rest of the house, especially low frequency energy.
A couple of things I would do/think about straight away:
- You need to make your existing space as airtight as possible. Seal every crack, hole, gap etc in the walls, floor and ceiling/roof. Use a non hardening caulk and if the gaps are big then use backer rod to fill the gap first, and then seal.
- You probably have a vented roof, which means there will be penetrations to let air in and out so that condensation doesn't form on the underside of the roof deck and on the timbers. You cannot block this ventilation up, but you also need an air tight building, so what to do? It depends on what type of ventilation you have (soffit vents, ridge vent, tile vents, felt lap vent etc) so let us know what you have there, but you'll probably have to put plywood/plasterboard on the bottom of your rafters, leaving an air gap (at least 50mm) so that air can freely come in and out and keep the roof deck ventilated. The new plywood/plasterboard will be a continuous layer that is sealed all the way around and meets the walls to form a complete airtight "bunker". Then you'll build a whole new inner room within that bunker.
- You mention that you have brick walls - that's good. But your ceiling will need to at least match the surface density of the brick in order for it not to become the weak point in your build. It's going to be very difficult to match the density of brick using plywood and plasterboard, so you'll have to increase the air gap at the ceiling to make up for the lesser mass. This means your internal height will be a lot lower than it currently is. Also, the current beams are going to get in the way and not enable you to maximise your height. I would speak to your structural engineer to see if they can be removed and another method to support the roof put in place.
- Once you have your sealed outer shell and your new sealed inner shell you'll have to penetrate it to put fresh air in and take stale air out. The ventilators that you linked to will not be good enough to maintain a high level of isolation because they are very lightweight and provide a direct connection between inner and outer leaves. They also look quite small which means they likely would not provide enough fresh air for more than 1 or 2 people. You'll need a complete HVAC design which maintains isolation but provides enough air for your needs. Then you'll also need at least cooling, so you'll an air conditioner, and they usually have an outside unit. This means you'll need space for that somewhere outside, and then you'll need to work out how to connect it to the attic space.
Those are my thoughts for now, hope it helps.
Paul
