John Sayers' Recording Studio Design Forum Archive

has cinderblock walls, a concrete floor (currently overlaid with partial asbestos tile) and is buried about three-quarters underground.

That's a great starting point! You already have a lot going in your favor there.

I’m assuming that the windows are the main culprit. Is that pretty safe to say?

Yup! But I'd also look at your HVAC, doors, electrical system, and the floor above you.

Since I’ll ultimately need to beef the windows up as part of my outer leaf anyway (I definitely want to keep them as windows,) would it make sense for me to just go ahead and replace those now?

Absolutely! You'll need to do that anyway, down the line, so you might as well do it now. That could make a fairly nice difference to your isolation at present, if you get the right glass in there.

If so, is that something your “average window guy” can handle? I know I’m supposed to use a really thick type of glass. Do most window contractors stock that?

Yes, yes, and maybe. Three questions, three answers.

Yes, most glaziers should be able to handle that, yes you need thick laminated glass with an acoustic interlayer (if you can afford it), and no, not all places would stock that, but the can probably special-order it for you.

but you might also need to beef up your window frames, or replace them with better frames. It might not be possible to put that nice new pane of very heavy, thick glass in the frame you have now. So do yourself a big favor, and replace both at once. You need a fixed, non-opening window there, in a thick sturdy frame, and all of it must be very, very well sealed.

Are there details, in terms of sealing the things and whatever else, that I’ll need to make them aware of?

The glass must be totally sealed to the frame, full perimeter, on both sides of the glass and also around the edges. And the frame must be sealed into the rough opening in the same way. Sealing is critical. No gaps allowed. Not even a pinhole.

I’m fine if they’re “non-opening.” Is that something they can do?

The have to be non-opening! And yes, when you order your new window/frame combination, specify that it must be fixed, non-opening, fully sealed.

I’m thinking that because, while the house does have central a/c, and the air handler is conveniently located near the drum space, I somehow have it in my mind that the vents + mini-split scenario will be easier and cheaper. Please set me straight if I’m wrong!

You might well be wrong! If your HVAC system already has the capacity to deal with that room, then it might be easier to tie into it, through silencer boxes, rather than to install a separate system. Check with your HVAC guy to find out if the existing system does have enough capacity to deal with your room.

do I need to be thinking about using the existing window holes as “ports” out of the house to eventually run the air ducts?

You could do that, yes. But if that might be the case, you need to figure out how big your ducts would need to be, so you can see if you need all of the window area to get your ducts in and out, or maybe only some of it, in which case you can still have windows.

One thing about windows in basements. Sometimes they are required by code as emergency egress paths, in which case you cannot get rid of them legally, and they would probably have to be operable (openable). Better check that.

but I’m wondering if having “non-opening” windows in the eventually-finished room will put me at greater risk for health issues.

I'm not sure about that at all, but if you build your HVAC system correctly, there would be a constant flow of fresh air coming in from outside, and a constant flow of stale air going outside, so my guess is that it would not be a problem. Also, assuming the radon treatment was done correctly, all of the radon should be going up the vent pipe, not getting into your room. But I would check with a local expert on that, to make sure.


- Stuart -

Thank you very much, Stuart. This is all tremendously helpful. I really, really appreciate your time!

Could I follow up with one other question? Is it worth it for me to consider building the windows and frames myself, or is that not viable since they're not just "studio" windows but bona fide exterior house windows?

Sure, you could do it yourself, if you are reasonably good at carpentry.

- Stuart -

Thanks again!

Hey guys -

It's me again. Hope you're all well.

Wanted to run a conundrum by you that's currently bugging me and could have serious implications on whether or not I'm able to build my room.

So, as I've mentioned, my basement is about three-quarters underground. It's all cinderblock. It's divided into two sections, one of which will be the future drum room.

After having an uncle over recently who's a carpenter, he pointed out that my build may not be permissible due to egress considerations.

So, throughout my entire basement (in each of the two rooms,) there are a number of small windows that run along the upper perimeter of the walls. They're probably not any bigger than 2.5ft. long by 1.5ft. tall. They're really old and janky--probably original to the house, which was built in the 50s. To escape in the event of a fire, I'd likely have to climb a ladder, break one, and attempt to fit through.

Now, on one side of the basement--the half that's NOT the future drum room--there's a small staircase that leads up to a door that opens directly out onto my screened backyard patio. My uncle noted that this probably would not serve as a proper means of egress, as in order to escape during a fire, I'd have to come out of the drum room through two closed doors and up the stairs to the backyard patio door.

I emailed the city code guy to ask him about this, but he hasn't gotten back to me.

In my note, I basically asked him a.) whether the current situation (having the stairs in the non-drum room side of the basement) would be an acceptable means of escape, and b.) if not, whether putting a new easily-opening window in the non-drum room side of the basement would serve as a proper egress path.

I obviously proposed "b." because installing any sort of opening window in the drum-room side wouldn't be an option.

Do you guys have any thoughts?

I obviously can't build one of those windows in the drum room that lets me open it and crawl up through a little crawlspace to the ground above, right? That would be insane!

Thanks in advance for your advice. I'm really hoping there's a solve here!

Just wanted to bump this and see if anybody could help a brother out.

n1ck wrote:I emailed the city code guy to ask him about this, but he hasn't gotten back to me.

Hy Nick, my thoughts are that you need to wait for this guy to get back to you unfortunately. If he's the man who signs the paperwork, then he's the man who's answer you need. Proabaly worth a follow up email or call though if they're anything like local council in Australia......very hard to get answers out of sometimes.

all the best,

Steve

I obviously can't build one of those windows in the drum room that lets me open it and crawl up through a little crawlspace to the ground above, right? That would be insane!

Well you COULD build such a window if you really had to, but the cost would probably be "insane" for sure! You'd need pretty thick glass in each leaf, several seals, a large gap between them, etc. It would be big, and and heavy, and expensive.

I'm really hoping the inspector guy has some good news for you!

- Stuart -

Thanks for the feedback, guys!

So the inspector did write me back and tell me that I'm allowed to install fixed exterior windows in my drum room. So good news there!

I think (and I hope this doesn't end up being a giant mistake on my part) that I'm gonna try to build and install them myself. Finding prefab ones that meet my needs is just proving to be too hard.

Question for you, though: looks like the thickest laminate available is 1/4". Is a single pane of that stuff enough for each of the three windows, or should I sandwich two of them together for each one to form a single mega-pane?

Also, in terms of really sealing the window frames to the cinderblock that surrounds each of them, my construction buddy suggested using a layer of sylicone to sort of "caulk' around the entire perimeter. Would that make sense?

n1ck wrote:I think (and I hope this doesn't end up being a giant mistake on my part) that I'm gonna try to build and install them myself. Finding prefab ones that meet my needs is just proving to be too hard.

If you're pretty good with the tools then a fixed window shouldn't be too difficult. I'm pretty sure Rod's book has a detailed drawing in for building fixed windows.

n1ck wrote:Question for you, though: looks like the thickest laminate available is 1/4". Is a single pane of that stuff enough for each of the three windows, or should I sandwich two of them together for each one to form a single mega-pane?

You should be able to get a thicker laminated glass than that surely I've got 11mm laminated and that wasn't the thickest I could get either. I also don't think that just putting two panes in yourself is the way to go as there would still be a small air gap in there which could null some of the isolation properties of your window. When a glazier laminates two sheets together, they put in a layer of PVC or resin which bonds the two sheets into one.

As far as isolation goes, you need to match the surface density of you exterior wall with your windows to get the best isolation that you can. Hopefully Stuart will drop past this thread as he has a much better grasp of surface densities than I do, but I think you're looking at a 15mm + laminate to match your walls.

n1ck wrote:Also, in terms of really sealing the window frames to the cinderblock that surrounds each of them, my construction buddy suggested using a layer of sylicone to sort of "caulk' around the entire perimeter. Would that make sense?

Yep, that sounds right to me. Make sure you use an acoustic sealant like the one that Green Glue make. It won't shrink and become brittle over time and open up air gaps like a regular caulk does.

all the best,

Steve

Thanks, Steve! I appreciate it.

On another note, would someone be able to refresh my memory on how many air-changes per hour generally need to happen in a basement room-within-a-room scenario? I know code is usually where to look for that type of info, but I seem to remember someone mentioning 'eleven' on here at some point as a rule of thumb. I searched and couldn't find anything.

Once you know how many room-changes are needed per hour, how do you then use that knowledge to calculate the right HVAC gear you'll need? In general terms, I'm thinking a line in for fresh air, a line out for stale air and a mini-split, but I'll obviously need to figure out the diameter / length of ducts, fan-type, etc.

The room will be mainly for me practicing drums, but I'd like to be able to comfortably provide for a few dudes playing amplified rock-band instruments in there from time to time.

I realize I'm jumping around with questions, but after all this window talk, I just remembered I need to verify how big my ducts will need to be in order to preserve some window space for them!

I'll obviously wanna do silencer boxes, so I'll need to do account for those in determining the length of my ductwork, as well.

Thanks very much again, guys.

Just wanted to bump this bad boy to see if anyone could help me with the query above.

Guys -

Forgive the poor iPhone pic. Can I get a quick consult from someone who knows what's up with windows, if possible?

If I were to build my own 2x8 frames into the rough masonry openings seen below, how would I deal with the voids created along the sides, bottoms, and (especially) the corners where the 2x8s won't butt up all the way against the blocks?

Prior to running into this problem I had planned on using butyl caulk along the entire perimeter, but now am wondering if I shouldn't use that pink / yellow foam crap. It seems like if I use caulk I'd be caulking for days, and I don't know that that'd even properly insulate gaps this wide, would it?

Anyone have a strong perspective on this one? Thanks so much!

n1ck wrote:Forgive the poor iPhone pic.

doesn't look like the photo uploaded mate. It would be helpful to see what you're seeing if you can manage it.

n1ck wrote:Prior to running into this problem I had planned on using butyl caulk along the entire perimeter, but now am wondering if I shouldn't use that pink / yellow foam crap. It seems like if I use caulk I'd be caulking for days, and I don't know that that'd even properly insulate gaps this wide, would it?

It may be possible to use expanding foam in middle of the cavity to add a very slight redundancy for your outer seals, but use an acoustic caulk for the outer seal between the timber frame and the masonry. If it's not sealed air tight then it won't perform to the level you require.......and yes, you will caulk for days. That's probably rule number four in studio builds: Thou shalt use an obscene amount of acoustic caulk. Caulk everything. Seal everything. You only get one real chance to do it right without having to pull things apart to re-do them.

The technique which is mostly used is to use backer rod to fill the cavity so you can run a nice bead of sealant against it.

all the best,

Steve

Thanks, Steve. Not quite sure what happened there with the pic. I tried to attach it at the bottom this time. Can you see it?

I guess my concern is: on the right side, for instance, it seems like there's going to be a consistent 1/4" void from the inner face of the window all the way to the outside world. The idea of filling that entire cavity with caulk seems crazy to me. Will having just caulk (particularly the acoustic kind) provide enough of a weather seal for my needs? This is an exterior window in my basement.

How do you apply the caulk so that when you're pumping it through one side it doesn't make a total mess as it eventually pumps out the other side? Wouldn't it all start pumping out as you fill the whole cavity up?

Thanks!