Multi-purpose Music/Home Theater/Recording Studio

#1

Hello!

As a reminder, I built a 24x40 building and I am now ready to create a room for a gym (in the front) and a large room for the studio. The first step is to finish the gym so I can transfer things from the studio into the gym.

Although my design thread is currently in progress and I will continue it soon (see https://www.digistar.cl/Forum/viewtopic.php?f=5&t=1229), I thought I could start the construction of the gym and the walls that separate the gym from the studio, and that's what I did with the help of a friend who is an electrician and has more experience than me in construction.

He first installed (temporarily) a few electrical outlets, two lights, and the switches at the entrance. This has already been planned in my electrical plan (which I will soon publish in the design forum). The breakers for the studio equipment will be on one phase and the other things (lights, fridge, treadmill, etc.) on the other phase. However, the breaker for the radiant floor system must use both phases.

The dividing walls start about 11 feet from the front wall. Since there was no 2x6 stud at that distance in the left exterior wall, we added a stud to secure the first dividing wall. But we didn't add a stud for the second wall because the next stud isn't far away. This results in a 4-inch gap between the two walls (between the end of the 2x4 on one wall and the beginning of the 2x4 on the other wall). However, in order to align with the other exterior wall, we had to add 2 studs in the other exterior wall. For each stud, one bracket at the bottom and one at the top (on the same side of the stud), plus 2 nails. Finally, re-nail the Enermax strip and red tape.

Since the interior walls have to rest on the floor and the floor is a few inches lower and further back than the exterior wall (the bottom of the Enermax is 7 inches higher than the floor), there needed to be a way to secure the interior wall and also decouple it from the exterior wall.

We first attached a decoupled 2x4 to the Enermax. To do this, we used anti-vibration rubber pucks and pieces of rubber tubing inside the 2x4 to insert a lag screw. The tubing protrudes a little on each side, so by screwing the lag screw into the 2x6 (through the Enermax), the washer flattens the tubing on one side and on the other, the tubing merges with the puck. 4 washers for each 2x4.

But the 2x4 attached to the Enermax is too far from the floor, we need another layer of 2x4. So we attached 4 pieces of 2x4 just above the lag screws to attach the interior wall, which rests on the concrete.

#2

We then built the walls but without permanently fixing anything in order to properly build the frames for the 2 sliding doors and make sure everything fit together. When the structure was finished, we permanently fixed everything. Unfortunately, I didn't think to offset the studs on the second wall, which would have been better. But by putting wool between the 2 walls I might be able to reduce the impact of this mistake.

The sliding doors are placed on 1/4 plywood that will be glued to the concrete. Under the threshold of the doors, I will try to find a material like neoprene to decouple the doors from the plywood. In the end, I left only 13 inches between the 2 thresholds instead of 24: this allows for a step and leaves more room for the studio.

Since I have a glycol radiant floor, I can't risk puncturing a pipe by nailing the bottom plate. I glued it with PL Premium glue, but first I removed the concrete sealant to allow the glue to adhere better. And I put in a door to create a weight.

Since the walls are quite long (22 feet) and the patio doors are very heavy, I decided to also attach the walls to the ceiling with the same system as the side walls.

After building the door frames, we removed the doors to make it easier to move materials into the studio.

Next Monday we will finalize the structure of the small walls on each side of the doors and the one above.

Questions:

1) the doors are house doors so they have sloping thresholds that result in a large opening at the bottom. Do you have any suggestions for filling this gap before sealing?

2) I plan to install Owens Corning Pink Next Gen Fiberglass Quietzone Insulation in each wall, which is almost 3X cheaper than Rockwool Safe'n'Sound. Is this a good choice in my situation?

3) In addition to putting wool in each wall, should I also put some in the 4 inch space between the walls?

Obviously, any suggestions will be welcomed with the greatest interest.

Stef

#3

add some more king studs on either side of the door jam jack stud to reinforce it. which seems to be the plan...

on the threshold - consider replacing them with proper drop seals and match thresholds - zero international & pemko are good ones.

e.g. https://www.pemko.com/en/products/door- ... emko_12036

#4

I'm going to put fiberglass wool in each wall (see the 2 pink lines). If I also put a 7.5 inch strip between the studs that face each other (see the blue line), will that make a significant improvement or is it not worth it?

#5

no, you DO NOT want to connect the walls - otherwise you could have just skipped the dual wall approach... you do need to brace up on either side of the door - on each wall - NOT connecting the walls. you also need to add some blocking on the walls to A) strength them, B) support the insulation :-)

#6

Looks like I almost made a big mistake! Thanks Glenn!
Yesterday, I just reviewed Auralex's Acoustics 101 document (page 21) and was planning to follow their advice to use stringers.

So, 1+1=2

Stef

#7

Instead of the 2x4 stringers, we put a slat to strengthen the walls and prevent the fiberglass from sagging between the walls. I hope I didn't do something stupid! :roll:

#8

usually you would place the "blocking" or "noggins" between the studs to support it, i think having it behind the insulation will be less effective. as a note, sofy or semi-rigid insulation contacting between the frames is less of an issue than simply having it sag and leaving open spaces on the walls or between them. so consider adding some insulation hooks onto the straps so it's a positive grip on the insulation.

#9

In fact, the slats will serve to reinforce the wall and prevent the wool from one wall from falling onto the wool from the other wall.

Since my last post, we've made progress on the gym. Some electrical work, audio wiring for the gym sound system, cat5 cable for the TV, the 5/8 4x10 drywall is almost complete, and the small toilet is finished (2x3 studs, 1/2 drywall). The plumber came to run a pipe in the toilet. He'll come back to finish the plumbing work when the toilet is painted. I'm not going into too much detail here, it's more to make it easier for you to follow the steps I'm doing. But if you have any questions or see something that doesn't seem right, don't hesitate!

Here we see the 2 cables for the speakers (1), the cable for the sub (2) and the electrical plug for the ERV and the wire for the Duct Heater (3).

Here we see the socket for the toilet fan (1), the socket for the small water heater (2) and the outside water outlet (3).

Here we see the finished drywall in the bathroom, complete with the 24 inches pocket door. Above the ceiling, I'm going to install 5/8 osb. This will make taping & mudding and painting easier, and this space will be used for storage.

After some thought, I'm going to install a suspended acoustic ceiling in the gym. This will hide and soundproof the ERV ducts in the gym (however, in the studio they will be in a soffit). Next Monday, we should be able to finish the drywall. Then I'll have the plastering done by a contractor. I hope it will be available soon.

#10

Since my last post, we finished the toilet roof (with leftover OSB from my 2012 roof...

). Very strong!

We finished laying the drywall and the plastering was done between April 11th and 16th (4 visits). I am very satisfied with the result. Before plastering, I put acoustic sealant in the 2 corners of the wall that separates the gym from the studio (red lines).

I took advantage of this break from building to do a related project: my Recording light. I didn't invent anything, I just applied what I saw on YouTube. I used the Porto box I brought back from my trip to Portugal last fall. Recently, when I saw this box (which I had kept "just in case") with its sliding plexiglass front, there was a spark in my brain! :idea:

Cutting out the self-adhesive letters

Putting letters onto the plexiglass and 4 coats of paint

I found a 10 inch led light and a wifi electrical outlet (but I had to cut the 2 metal parts)

Final result

When it comes time to put it on the wall, I will only have to drill a hole in the back of the box to pass the electrical wire to connect the outlet. The outlet is WIFI and I can turn it ON/OFF remotely with my phone. I had to shorten the light wire. The installation is not very orthodox from an electrical point of view but is still safe.

Finally, I have a question regarding the ceiling closure at the junction of the dividing wall. Since I had to use slats to attach the wall to the trusses, there is a gap to fill (and it will be the same on the studio side).

To close this space, here's what I thought I'd do:
- screw a slat vertically onto the top slat
- screw this slat into a horizontal piece of OSB
- screw another piece of OSB onto the top plate

- seal all joints
- on the other side I will put fiberglass

All of this will not be visible because it is above the suspended ceiling.

QUESTIONS:

1) Over the material I put I could add a layer of gwb 5/8 and seal....is it worth it?
2) Do you have a better idea to close this space?

Stef

#11

gaps in the mass boundary (mass, missing altogether etc) will result in isolation reduction. so match the mass - walls, ceilings, floor, windows, doors, and ensure no direct paths for openings (wiring, ventilation, etc).

#12

Thanks Glenn. I think I understand what you mean, but I have to work with the current structure, and since I'm not an expert, I'm having trouble finding the best way to do it...so can you tell me what you would do specifically in my situation? Then I might be better able to determine what I can do within my capabilities and means.

#13

"ceiling closure at the junction of the dividing wall. Since I had to use slats to attach the wall to the trusses, there is a gap to fill"

so the "slats" used to attach the wall to the trusses is somehow not even with other frame members? meaning you cannot continue the drywall almsot up to the ceiling and then backer rod and caulk to seal it?

#14

This is unfortunately true. In January 2013, just before I shut everything down, I had put two layers of slats in the gym area (ceiling and left wall) to make it easier to wire the electrical wiring. I stopped at about 11 feet, which was the distance I needed for the gym.

To fix the walls directly to the trusses, we had to add pieces of 2x4 between 2 trusses in different places (to fix the top plate with acoustic clips, for example). The option of doing it through the attic seemed so much like a nightmare to us (difficult to walk on the trusses, to move around, impossible to stand, wearing a mask, providing lighting, etc.) that the option of doing it from the inside (by removing pieces of Enermax) did not come to our mind. Yet, we did it to add studs on the exterior walls! What idiots we are... :cop:

We then opted to use the second layer of slats to fix the walls. We first had to add a slat on the next truss (1) so that we could put additional slats in the other direction (2) to fix the walls (circle).

So the challenge here is to close the following places as best as possible:

1- from the side of the gym, close the top of the wall (1) and the wall/ceiling corner (circle) (will not be visible because of the suspended ceiling)

With a 4x10 gwb

My first idea is the one I wrote in my previous post.

2- From the studio side, close the wall/ceiling corner (circle), the wall/Enermax corner (1) (more complicated because we are now blocked by the second wall...); From the gym side, close the hole for the electrical wires (2)

Same place

Studio side view

I fully understand that this situation is not ideal for a studio designer... :ahh:

So, what you would do to solve these problems?

Thanks again for your help.

Stef

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