New Studio in Turbenthal

OK, I've found a different product which numerous people here (locally) have suggested I use (including my house architect), so perhaps you can tell me if I'm good to go with this product. It's called Fermacell and for a 15mm thickness weighs 18 kg/m² compared to normal drywall (data from Knauf) which has a weight of 12.2 kg/m² for an 18mm thickness (14.4 for 18mm special firewall) and only 12kg for 15mm. I can attest to it being much heavier, having tried lifting it and the normal drywall. I also finally found some useful wood sizes for the framing (Spruce or Fir): construction grade timber: 40mm x 60mm @ 1.50/m and 50mm x 50mm @ 1.58/m or planed timber: 55mm x 75mm @ 5.18/m and 55mm x 55mm @ 4.36/m The cheaper construction lumber won't give me a very decent depth for treatment at 60mm do you think I should go for the more expensive for the extra 15mm?

Hey Brian, I'm in France so know Fermacell well. It's used in construction for outside applications as it's completely rot-proof. If I remember well it has a mass of 1300 kg/m3 compared to about 550 kg/m3 for good quality drywall (Placoplatre or Knauf). Thing is it costs a bomb so I ended up going for 2 layers of 13mm drywall sandwiching green glue. Make sure you don't buy the low-end plasterboard (marked only CE, which you can find at Brico Depot and other DIY chains) but the good quality one (again marked CE but also bearing an NF stamp or whatever it is in Switzerland). Building code (at least in France) makes the use of the latter one compulsory for ceilings and commercial walls - reason being that it's denser, hence heavier, which is what you want.

Right, typically a thicker material and fire rated.

for a 15mm thickness weighs 18 kg/m² compared to normal drywall (data from Knauf) which has a weight of 12.2 kg/m² for an 18mm thickness

Sounds like good stuff! With that kind of mass, you should be fine.

I also finally found some useful wood sizes for the framing (Spruce or Fir):

All of those dimensions seem to be bit on the thin side, and not really "standard" sizes at all. I would go with at least 2x4, which is something like 40 x 90 mm for the walls, and something much beefier for the ceiling, maybe 2x6 or 2x8, but you should someone who knows what they are talking about to give you the exact dimensions, based on the load, span and type of wood. - Stuart -

"maybe 2x6 or 2x8, but you should someone who knows what they are talking about to give you the exact dimensions, based on the load, span and type of wood." 2X6, this will (southern pine) span 13 feet(ish from outside to outside of framing dimensions) with all other things under consideration, being taking into account. For your 9 foot span, there is no reason to get any larger than that.

SoundMan wrote:

not really "standard" sizes at all.

It's useless to argue about standards here (in Switzerland). Someone once told me, upon my discovering that something or other was available, "We're not behind the moon you know!" Well they might as well be sometimes.

XSpace wrote:

For your 9 foot span

I think you missed in an earlier post where I explained I wont be hanging a full ceiling, as the existing construction is already two leaves, tests indicate I currently have no noticeable propagation issues to the room above.

I tend to be somewhat wary of “experts” here (in Switzerland) – I had an ‘acoustic consultant’ come by and have a look and as I described my intentions with isolation walls he seemed to become somewhat hesitant. Although now retired, it seems he built up his company selling wall treatments consisting of 10mm thick open-cell foam covered with fabric – basically carpeting for walls. Needless to say he realized I wasn’t about to become a customer. Remember this is Switzerland – where the Placebo was invented! However, I had a discussion the other day with a chap who is involved with the (rapidly growing industry) construction of home theatres. He admits he’s not an acoustician, but talking with him he seemed to know a thing or two. So he had a look and I showed him my plans and intentions. And we put things into perspective. First, it is a cellar room, and not a living space, so apart from any propagation into any living spaces, the permitted emission levels are not as stringent, and the existing walls are well within, and even exceed building code requirements. Secondly, the adjoining cellar rooms are being used for storage, so people will rarely ever be in them. I explained this is true but as these are classified as multipurpose rooms, that could change. The guy in the room across the hall from me watches DVDs in 5.1 in his room. (I can’t hear any trace of sound in my cellar, but in the hall the emissions from his room are similar to the levels I had during my tests (see earlier post). Another guy at the other end of the building has set up an office in his. Third, this is not a commercial studio and will not be used for tracking live bands, furthermore, it is quite small and the Db levels will probably rarely exceed 80 tops. We discussed the walls and ceiling and he said that this was a common problem in cellar installations, that the height is a limiting factor. I asked if he thought I should take down the insulation and make the walls full height. He said too (as is oft described on this forum) that the correct way would be to construct a proper isolation ceiling fully separate from the existing – but agreed, not in this case, because of the third leaf effect plus the fact that it is already very low. He said that taking the walls up to the concrete could conceivably exacerbate propagation to the apartment above which currently is not a problem. He mentioned that nearly every job they do there are always compromises that have to be made. He found my idea of creating a partial ceiling or lip very intriguing, but said I should take the lip all the way to the brick wall and try to create a seal with neoprene or silicone for the air space between the walls. He highly recommended using Fermacell over Gyproc, explaining that it far exceeds normal plasterboard in all respects, fireproofing, water resistance, holding screws (even with shelves), and can also be used on floors. He is of the opinion that I just use a single layer of 15mm. A second layer would not necessarily bring more isolation because of the construction, so may not be worth the extra cost. The money would be better spent on treatment inside the room which he said would be the lion’s share of the entire project especially considering the room’s small volume. Good absorption within the room will also help reduce emissions. He’s very keen on hearing how it turns out particularly with regard to the Lip. He might even try using the technique on some of their builds. I’m now a little unsure about whether I should use 1 or 2 layers on the walls. Any further opinions?

BriHar wrote:

XSpace wrote:

For your 9 foot span

I think you missed in an earlier post where I explained I wont be hanging a full ceiling, as the existing construction is already two leaves, tests indicate I currently have no noticeable propagation issues to the room above.

Your current picture suggests that you are indeed going to be framing for a ceiling. And if the existing structure is already 2 leaves, this presents a third leaf.

from a earlier post wrote:

The ceiling is 250mm reinforced concrete to which 80mm dressed, rigid glass wool panels have been affixed for general reverberation control (this is applied throughout the entire cellar i.e. all rooms). Above this there is a 20mm layer of thermal insulation (kind of like styroboard with aluminium foil on each side) then a 20mm acoustic insulation layer (footstep), PE Foil (vapour barrier?) then 80mm cement poured over the heating pipes (floor heating), finally a 10mm layer of fine cement (screed?), then either parquet or ceramic tiling. This is then the floor of an apartment above.

I simply intend to create about a 1/2 meter perimeter around the top of the walls.

from a earlier post wrote:

After seeing the ceiling insulation which has been applied, I am concerned that my isolation walls should go right up to the concrete to establish an airtight cavity and true MAM construct. It appears I can’t take the insulation down apparently because of building codes or certification (Minergie) so, for the isolation level I’m likely to need (the walls are supposed to have an STC rating of around 50 as they are), and as I’m not doing ‘room in room’ I’m going to make the following compromise. The main considerations are the breach in the dead air space between the walls, and in the critical corner boundary. I will take the Isolation wall up to the Insulation, leaving just enough space to attach 30 – 50cm wide MDF or gyproc sheets to form a lip or partial ceiling at the top of the wall. These panels will be attached and sealed to the top of the isolation wall and will fit snug against the insulation panels affixed to the ceiling (also perhaps with acoustic caulk or acoustic weather-stripping between). This construction should hinder the sound flanking directly over the top of the wall, re-establishing the integrity of the corner acoustically, and increase the insulation path to the outer wall improving the seal breach in the dead air space (perhaps also acting as a kind of ½ meter deep trap). Keep in mind this a compromise and is not an ersatz for RIR isolation nor deemed as effective as full floor to ceiling construction.

Well I've ordered some materials so I can begin work perhaps in a week. I ordered 60mmx80mm lumber for the main framing and 60mmx60mm for some of the additional construction. I was rather indecisive about using a single layer of fermacell as the guy I talked with suggested would be enough, so I bought enough to do 2 layers anyway. Cost is not so much a factor for me but I figure it'll be a heckofalot more trouble trying to add a second layer later so... For inbetween the walls i ordered Rockwool WLG 040 half-rigid 60mm panels. I have to wait until next week to get confirmation they can deliver this otherwise I'm looking at Isover Isocomfort 035 which is a horrendous price compared to the rockwool. The older type of fluffy insulation (paper or foil backed) is pretty much impossible to get here now and is even more expensive than the semirigid. The other possibility is Rockwool Floorrock WLG035 which is only 20mm thick or Isover PBM2 80mm, which again is much more expensive but I'll probably get that over the floorrock which is actually mean't for footfall under floors.

The rockwool is available :D So the lumber, Fermacell and Rockwool should be delivered next monday. :yahoo: I'm taking a couple weeks holiday and in this time see how far I get in the build.

Well the material was delivered on the following Tuesday, and I've spent the last two weeks building the walls. Should I begin a new post in the Construction Forum, and provide Links between these two posts? Before I detail the build though, I have a question regarding ventilation. In the following diagram, the Red lines are the air exhaust and the Blue lines are the fresh air delivery. The Exchanger unit is located at the far left. The room in question is the gold rooms "Keller 8" and "Hobbyroom 8" on the right. The Hobbyroom will be the studio. Fresh air is piped into the Kellerroom and extracted from the Hobbyroom. The path between the room is under the door! As it is my intention to add a second door, and add a door sill with rubber seals for both doors, this ventilation path will thereby be cut off. I therefore intend to put a 6" (= diameter of air vents) hole in the wall by the door (nearer to the ceiling) and provide a silencer on the inside of the Studio between the brick wall and the Isolation wall. (The inner isolation structure is not shown in the diagrams here. The proposed vent is marked in green) I was wondering if I should include any sort of fan in either of the silencers (there is another silencer planned to affit to the exhaust vent in the Studio)?

I might have missed something about your ceiling, but how are you attaching the plasterboard? Is the central section of the ceiling open?

Yes the central section is open. The drywall only forms a perimeter roughly 1/2 a meter wide, which serves to seal the tops of the Isolation walls each side. The area where the pipes cross the ceiling (roughly about a 1/3) will be soffited and sealed, as will the ventilation duct by the front wall. These compromises are due to the existing construction which is already 2 leaf (ceiling and front wall) and quite effective as is in terms of isolation. This construction is best seen in the pics in post from Apr 4 on page 2. viewtopic.php?f=1&t=15635&start=21

I've decided to keep going with this post and if should be subsequently decided, can be moved to the construction forum. So, From here begins the Construction Phase _________________________________________________________________________

To begin, here are a couple of photos of the room. The door is still on the wrong - i.e. inside. This has finally been remedied. In the meantime I busied myself filling in tiny cracks and holes in the mortar. I also caulked the seams between the brick and concrete walls, not to mention around the ventilation duct. I've also been running a dehumidifier, It seems I can get it down to between 50 and 55%. Here's the lowest I've registered:

I haven't been completely alone in this endeavour, Murphy has been giving me a hand now and then. :lol: :cry: The material was supposed to be delivered on the Monday morning, it came instead on the Tuesday. Finally I can get started :) Oops, it seems my saw won't cut deep enough for the 60mm x 80mm :shock: OK, so first I've got to go and buy a new saw :roll: Now the wall frames right and left have been constructed. Each side comprised of two sections which bolt together, or would if my drill bit were longer :roll: These frames each anchor to the cement floor ... now why the devil won't the bit go any deeper, I'm using a hammerdrill with a masonry bit... :? It seems in a couple of holes, I hit rebar :shock: So Ill go buy some more drill bits :roll: Next begins the paneling with fermacell. By jeez those things are heavy! :shock: The original plan was to construct the "inside-out" wall on the floor and then raise it into place. I realized that this was not going to work, as the end weight of the individual wall sections will be upwards of a 1/4 Tonne and there's no way to get enough manpower physically around to raise it, sooo.. I've decided to build the wall standing upright, half a meter away from it's final destination, and if it's too heavy to lift and drag, then I'll try using a car jack.

Murphy has been giving me a hand now and then

Ahhh! My good friend Murphy! I know him only too well. He's always ready and willing to "help", isn't he! :) :evil: :cen: :!:

The original plan was to construct the "inside-out" wall on the floor and then raise it into place. I realized that this was not going to work, as the end weight of the individual wall sections will be upwards of a 1/4 Tonne and there's no way to get enough manpower physically around to raise it,

Wall jacks!? You can't rent them where you live? - Stuart -

Soundman wrote:

Wall jacks!? You can't rent them where you live?

The wall jacks have yet to be instsalled but they are reserved for telephone and network. ... or are you serious? At any rate, as I was applying the first layer of Fermacell, it occurred to me the screws I bought were mean't for the second layer, i.e. longer than necessary :x , secondly, the power screwdriver (B&D) was not up for the job :shock: So it's back to the store for more stuff. The Fermacell panels are spaced a few millimeters apart, these seams have been mudded with a special plaster from Fermacell which has better adhesion than normal plaster or joint compound, while also retaining the properties of the panels themselves. Later these mudded seams plus the mudded screw depressions were sanded in preparation for the second layer. These same seams will be caulked on the inner side of the wall. In the meantime I've added the second layer of Fermacell, ensuring that no seams coincided. The mudded seams on this layer have only been lightly sanded. The layer of Rockwool has been applied and kept in place with strips of chicken wire mesh stapled to the panels. I also used a spray adhesive here and there to tack the Rockwool in place 'til it was bound by the mesh (the adhesive alone would never hold the wool as it frays apart too easily). So, the section is finished and ready to be moved into place. A strip of 40mm wide adhesive backed neoprene seal has been applied to the top of the brick wall, where the Fermacell ceiling panels will butt against to help seal the space between the walls. Well my son came over and in about a half hour we had the wall moved into place (with the car jack) :yahoo: . Uhoh, it appears I let Murphy draw the designation lines on the floor at the time when I was considering a single layer of Fermacell. Much worse, the drilled anchor holes are also off :evil: :oops: At least the closed cell foam strip I affixed to the bottom of the sole plate survived the journey intact.

The wall jacks have yet to be instsalled but they are reserved for telephone and network. ... or are you serious?

Yes, I am very serious! When you have a wall that is too heavy or too large to be lifted by hand, you use wall jacks... http://www.industrialladder.com/listPro ... goryID=368 http://www.toolfetch.com/Category/Roofi ... /48583.htm That's the normal way of tilting walls into position. - Stuart -

Just a bit of confusion here....Wall Jacks: jacks to put a wall in place. vs. Wall Jacks: a place to plug in a phone line/ethernet cable etc. Symantics......lol

Ok Stuart, I figured you were serious. Must admit I've never seen these before. But you will notice that these work fine in an open environment (as the pictures attest). but in a confined room where the top of the wall is virtually the height of the room and as in my case where the height is also nearly the room width (about a half a meter to spare), it just wouldn't work unfortunately. My car jack idea worked fine though two jacks at each end might have been faster, but I simply moved the jack between the two ends and slowly walked the wall into place while my son kept the wall from tipping. Good to bear in mind though, and hopefully might help some others.

Update: Finally all 4 sections of the side walls are now in place. The final section was a little more problematic as I had to go around the plop pipe, but mission accomplished. Now I just need to do the framing on the front wall and one more isolation wall at the back - with a door in it. Then onto the soffits and ceiling rim. I was really kind of hoping for some comment on the ventilation I described earlier before I commence work on that wall.

Is it my imagination, or do I see sheets of drywall where the edges are nowhere near the studs, and are not attached to anything? :shock: Maybe it's just lines drawn on the wall, but from those photos, it looks exactly like the first layer of drywall was not put on correctly, and is offset a very large distance from where it should be: the edges are a long way from lining up with the studs (at least 10 or 12 inches). If that's the case, then firstly WHY was it done like that, and secondly what's the plan for keeping that drywall in place? How are you going to put more wood on those exposed edges and screw it in place, if you can no longer get to the other side of the wall? - Stuart -

Ah Stuart, you have the eyes of an eagle. Yes the seams between panels do not all ine up on studs. The studs are 60mm apart (except for either end which are closer together) to accomodate for standard widths of rockwool and fiberglass. First and foremost, you have to put drywall out of your head. These panels are all Fermacell which although similar, has many properties which are far superior to normal drywall. One of these properties is it's exceptional ability to hold screws! In fact the manufacturer suggests doing just this for multiple layers. In fact, they supply 3 different lengths of screws one for the first layer into studs, one for the second layer through the first into studs, and one extra short type for screwing just into the first drywall layer without studs. Other advantages of Fermacell panels are that just with the standard panels they are much denser than normal drywall, have a much higher impact resistance, and can even be used in flooring. They are inherently fireproof, and water-resistant, without having to buy special variants as one does with drywall (though there is a more waterproof version). In addition to a product specific jointing compound, they also supply a bonding agent which can be used to glue panels edge to edge. I elected not to do this but did use the joining compound on the outer seams (I will additionally caulk the inner seams). Something else that is possible with Fermacell that you could never do with drywall - you can soak it in water for about 8 hours, take it out and clamp it to a form. Upon drying it resumes all of it's original properties, and you now have a custom formed (curved) wall panel (Great for those curved plane diffusors, not to mention the possibilities for custom waveguiding walls for an RFZ). Finally, Fermacell is a 100% green product - all waste material is recycled back into the product which itself is made from recyled paper fiber and gypsum. So yes you see correctly, but this is a technique that can be used with this particular material, with no need for extra wood or framing. http://buildingmaterials.co.uk/Fermacell.html