cellar / basement studio in the uk design queries

Hi everyone right here goes, i've been using the search function on here as much as possible before asking what may appear to be silly questions but i'm still wondering if anyone can tell me if i'm on the right track or give me some additional ideas! I live in England and I'm in the process of constructing a small studio in the cellar of my new house (victorian - built circa 1896), which we own. The house is detached and seperated from the adjoining properties by a few metres. The cellar is totally underground, and there are no other rooms bar the cellar, so basically on the other side of most of the cellar walls (which are thick engineering bricks) is solid earth, and the corridoor which leads down to the cellar. The cellar is about 3 x 4m in the main room, which i'm going to use as a drum practice room. I'm a loud drummer. The cellar has a single door which i've made thicker by adding mdf panels to it. We've damp-proofed the entire cellar and passageway (which was moderately damp previously) with a latex damp proof seal and screeded (concreted) floor, and used an oldroyd studded plastic membrane system (the studds on the membrane create an air gap) on the walls (sealed into the floor system). So basically any damp that tries to get in is allowed to circulate behind the membrane and not forced to stay in the bricks, but doesn't pass into the main room now. I want the room to be as soundproofed as possible (within reason hehe) so that sound doesnt leak through into the house above, and then outside. The living room above the cellar has wooden floor boards and i intend to seal the gaps with acoustic mastic once i get round to sanding the floor and revarnishing it. So on the cellar ceiling (currently just very large joists) i'm intending to use resilient bars with 2 layers of acoustic plasterboard (19mm and 12mm) with 100mm of acoustic mineral wool / rockwool (60kg/m) rammed in between the joists (The plasterboard isolated from the walls by a small gap filled with mastic). Does this sound reasonable, and is there any way of improving the amount of soundproofing without more ceiling height loss (the ceiling is already very low - about 6 foot 5). I'd also love to know how effective this solution actually is if anyone's done it. I'm also planning to apply a similar resilient bar system with two layers of plasterboard to all the cellar walls (but with thinner acoustic mineral wool to avoid losing too much space as the room is small), but i'm unsure of whether adding mineral wool is worth it due to the fact there is simply mud on the other side of the walls. Would it be viable it purely to stop sound transmission into then up the cellar walls then into the house? Another thing i've read about on here and other boards is mineral wool absorbing moisture if placed against another surface. This really concerns me. I can understand how mineral wool placed against a brick cellar wall (or other exterior wall) would absorb some of the moisture penetrating through the wall, but in light of what i said above regarding our damp proofing, would it be safe to push the mineral wool right up against the damp proof membrane before adding the resilient bars and then plasterboard? The membrane is made of a plastic and is "studded" so it has a series of small dips and raises to create an air gap down its surface, so would condensation likely be a problem? If yes, would leaving an air gap of a few inches between the mineral wool and the membrane help avoid this, and how would i achieve it, i.e how could i keep the wool away from the membrane. I'm also grappling with the ventilation of said room. I'm planning to have an air intake (with centrifugal fan) down the original coal shute to the cellar (with a sound absorbing box built into the shute, basically an S shaped chamber with mineral wool lining it / or ) but can't work out what density / thickness of mineral wool will give the most sound reduction (to avoid annoying the neighbours). Can anyone advise me? I'd imagine the duct will be about 4m long in total, so i was planning to line the entire duct surface with mineral wool. (i'd be making a similar sound absorbing chamber for the air outtake system). I've also seen a design which is basically a huge box full of rockwool with a gap at the top where the air passes through along one side of the box, but i'm unsure how effective this would be in comparison to the above design. And before i run out of breath, one final thing :oops: , i've read you can spray paint or varnish over mineral wool used in soundproofed ventilation systems to avoid the fibres getting into the air and thus all over everything, in your lungs, can anyone tell me if this actually works and if so what is the best method, or whether i should cover the rockwool with material (if so what material and how do i affix it hehe). If anyone can give me any help with any of the above it would be much appreciated, i understand i've asked a whole load of questions. cheers

Don't have much time ATM, but a few things - don't use that heavy mineral wool, and don't use it within your ceiling at all. For acoustic purposes and for duct lining, 3 PCF (48 kG) weight is ideal. Within ducts, (I've not tried this) I would think that nearly any paint sprayed onto the surface would contain any fibers from wandering through the ducts and into the air; but too heavy and it would decrease absorption. For sound barriers, mass-air-mass construction is by far the most effective and the "air" gap should have no heavier than 3 PCF weight - for lower frequencies, it's been proven that even LIGHTER insulation works best. ONe of the best choices for this is the "fluffy stuff" or normal weight household fiberglass insulation, slightly compressed between the two leaves of mass for a degree of damping of the panels. Moisture-wise - I'd seriously consider running a dehumidifier in the space every moment you're not using it - for one thing, virtually ALL wooden instruments (even drum shells of wood) prefer an environment that runs between 40-45% relative humidity, and no self-respecting English cellar would EVER be that low by accident :wink: Condensation only happens when moisture/temperature differences exist, so if you keep your cellar and the upstairs at nearly the same temperatures no moisture will be driven through the floor in either direction... Steve

Cheers Knightfly, that's all really helpful. With the condensation issue, i was more worried about moisture forming if the insulation was actually touching or close to the damp proof membrane.

For sound barriers, mass-air-mass construction is by far the most effective and the "air" gap should have no heavier than 3 PCF weight - for lower frequencies, it's been proven that even LIGHTER insulation works best. ONe of the best choices for this is the "fluffy stuff" or normal weight household fiberglass insulation, slightly compressed between the two leaves of mass for a degree of damping of the panels.

This sounds like a great idea, providing again theres no condensation issue with moisture migration. I'm actually running a dehumidifier in there all the time atm, seems to be doing the trick so far, thankfully.

Are you talking about moisture (vapor) migration from the outside coming through the walls, or about walls between two living spaces, or about vapor coming through the ceiling of the studio space from the living space above? Steve

I was primarily worried about moisture condensing on the surface of the damp proof membrane due to the temperature difference between the outside (i.e cellar walls) and the new room once the plasterboard is up

I'd put some poly strapping across the backs of your frame for the walls, http://www.uline.com/Browse_Listing_275 ... +Strapping (something like the yellow highlited one) - this can be stapled, or if you can build your frame on the floor and tip it into position it's better to use roofing tacks (25-30mm) - you just run the strapping perpendicular to the vertical studs at about 20-24 inch intervals, then tip up the wall frame and fasten in place, then add your insulation and wallboard. IF your wall frames do NOT touch the concrete wall, you won't need resilient mounts for the wall; but if your wall frame DOES contact the ceiling joists, then resilient mounts WOULD be necessary; also for the ceiling wallboard. It's 4 am here and I need to crash, HTH... Steve

cheers!