Heavy walls ?

Hi everybody, I'm a newbie here, but I'm on a big building project. As you can read, I'm french and my english is pretty awful, but I think I can explain to you my problem. Since I'm working on this project, I read a lot of things on the internet like Snap Studios building diary, some Philip Newell books... I'm ok for ceilings and floors but for walls... I'm about to rent the perfect building for my project. Over than 1100 sq meters are available for recording, mixing, mastering, video editing on the ground floor, rehersals and PA rental in the basement. In the SKP File attached with this post, you can find out building shape and first inside previews. According to most of my new knowledge, using hollow concrete blocks, sand-filled in mass-spring-mass systems is a really efficient building method. But this load cannot be supported... So here is my question : what lighter composite wall could replace this type of construction? This building is big enough to have large composite walls (1.50 meter if required). My goal is to get 65dB - 70dB of low frequency (80Hz) isolation. Is this possible ? Am I dreaming ? Or did you not understand my story ? You could reply to this with links if the subject has already been mentioned. Making some accurate researches in this forum is not easy for me ! Dam

Hi. I don't see a lighter wall giving you 70dB at 80Hz. Your wall would need to be massive and deep and have a fundamental low frequency resonance at 50Hz or so. A double stud wall with double 5/8" board on either side and insulation would get you to a theoretic 35Hz resonance (Fmam) or so, however the Transmission Loss at 80Hz would not nearly be 70dB. You might get 40dB. Adding a third sheet to each side might get you 45dB. These are very rough approximations.

welcome! could we get more information about the building construction (preferably before you sign the papers) because if you cannot support the walls you need then this might not be the "perfect" space unless it's location is the best and you have to live with what you rent. maybe there are options to reinforce the upstairs space so you can build the walls needed? if not, maybe changing the studio location would be better. for example, can you build the studio in the basement where the isolation may be much better and the floor can support the additional massive walls etc. then use the upstairs for the sales and rehearsal spaces.

The problem is that basement height is 2.65 meters. Creating a professionnal recording studio is impossible here. upstairs we've got 350 sq meters with a ceiling at an average height of 5.50m. This part of the building is the most beautiful place where a studio can be built. But its on a basement sadly too light for concrete walls. An other solution could be found in the second part of the ground floor (about 250 sq m). Ceiling is about 4.50m height but there is no basement. See the pictures below. Maybe the floor is stronger there. The building is made of metal beams and metal sheets (with 15cm of a thermical insulation foam between sheets). This is not acoustically perfect ! So we have to create an other building inside of it. The place is really nice : big car park, greenspaces, near downtown, and... with a lot of musicians all around !

have you had a structural engineer assess the structure to see if you can use the area over the basement or even the slab portion? you probably want to find out soonest because even framed walls suitably massive are still very heavy and you might not have support for those either.

I don't have any contact with a structural engineer but a building expert told me, as he was looking at the plans, that floor above the basement would support a maximum load of 700 kg/sqm. He also told me that the best solution to mount heavy walls seems to be building them directly above pillars lines you can see in the pictures. This is pretty restricting for designing ! What about aerated concrete ?

700kg/m2? AAC is about 20% of the weight of regular block not including any mortar, fill, grouting, rendering, etc needed. i think that helps but you'd want to verify that #. also, you want to investigate the structural sound transfer to determine if you need to float or floor or not. it might be more effective to isolate the basement ceiling instead. you need to consider the weight of the structure and ducting, plumbing, wiring etc etc in the basement if you will be suspending any of that off the floor above.

Hem... What does "AAC" stand for ? We would like to build some rehearsal rooms in the basement, so we would need a lot of soundproofing in there.