The Arizona Basement Build

Also known as the 'What!?, You Have A Basement!?' Build. Honestly though, basements are finally gaining popularity and becoming more commonplace in Arizona, although I've only seen a handful on these forums.

IMO, I'm not quite ready to make a build thread yet, but on the flip side, I think I could easily spend another 6 mo researching and unfortunately I get caught in analysis paralysis on things much simpler then this, so I hope this thread will help me get some feedback on the upfront design as well as push me to make progress.

Background
Never really been a video or audiophile (likely because I'm too cheap ), but for some reason I've always been fascinated by having my own home theater. Something about the experience draws me to it. Every place that I've lived over the last 10 years, I have more or less planned out in my head for a projector setup. Measurements, angles, screen size, light control, etc have been toyed with but I've never taken the plunge. I guess you could say that I enjoy the daydream planning but it'll be nice to actually follow through for once.

Over the years, I've read through various builds on this site and I was always so jealous of all the folks in the Midwest and East coast where basements were common place. My wife is also from the Midwest, so she has fond memories of growing up with a basement as well. That's why both of us were so excited to find one here in AZ. We are finally settled, and even better, settled in a place with a nice spot for a home theater.

So that's the good news. The bad news is that I have basically zero construction experience, am not very handy, and don't really own very many tools at all. Luckily other threads on this forum have given me confidence that those deficiencies can be overcome, even if it's slow and painful. Additionally, my father is a retired electrician (non residential) and my father-in-law is a general contractor on the side (albeit out of state). He comes into town every so often, like for example, this week . So time for me to learn - better late then never.

So while I'm on this good news / bad news approach, good news is my wife and I have a toddler and another one on the way. The bad news is that the wife will no longer be working as of next year, which seriously dampers my desire to cash flow this project. This will likely stretch out the timeline quite a bit. See how I blame that on the budget and not my inability to use a hammer?

Alright, so enough personal jibber jabber, let's get to the design.

Floor Plan
The basement is not that big compared to most on this site, a tad over 1000sq ft, but luckily it does have 9ft ceilings and uses a web truss system so all mechanicals are hidden away. The web trusses are 24" OC and 20 inches deep, so plenty of room for insulation. Additionally, there are no support poles in the middle of the room or anything like that.

The basement is what I would call half finished. This means that all the things are in place to make it technically livable space (more property taxes), such as HVAC, smoke alarms, sump pump, egress windows, ceiling fan prewiring, electrical subpanel, and framing all the way around the concrete walls. As I understand it, this is pretty rare since most builders here only deliver fully finished basements. The good news of course is that we get freedom of design and get to prewire to our heart's content.

Also I should probably mention that most basements here are built as an option, so all vital systems such as hot water heater, main electrical panel, and structured wiring box are upstairs. The basement has its own electrical 100 amp subpanel and the HVAC system is completely separate zone.

So this is not only a theater build, but also an entire basement build. The office will likely be first priority in order to free up a bedroom upstairs for baby #2.

Here is the floorplan so far:


Comments are welcome on any aspect of the basement, not just the theater.
Taking a look at the floorplan, grey walls are either outside walls or walls that exist already and I don't currently plan to build or change.

My office will be on the left side with built in bookshelves surrounding both windows. French door entry, which I wish could be used in the theater as well, but I have finally accepted that maybe that's not the best idea. The other side of the room will be a sitting area of sorts with plans for an electric fireplace (wife's request). Closet to maintain the ability to split into a bedroom later down the line.

Storage area contains shelving, an Air Handler (H) for the HVAC, and the sump pump (Triangle), which goes a little bit behind the stairs. Bath is a std size.

Open area after coming down the stairs will be left open for the most part. Maybe a flatscreen on the long upper wall later down the road. I'd like to be able to use it for kids play area, poker table setup, spillover room from theater. It contains a tiny wetbar in the corner which will have a few cabinets, a fridge, maybe some wine racks. Notice the '?' there, as I will have a weird gap if I line up the theater wall with the upper concrete corner. If I line up the wall with the lower concrete corner it eliminate the wetbar gap, but introduces the same gap on the theater side. It's about a 20" difference between the two corners. The diagram shows a 6" baseplate staggered stud wall, but at this point, I'm thinking I might as well build a double studded super wall to eliminate that gap completely.

The Equipment Closet (EC) has been a source of frustration lately. After reading through the "What Would I Do Differently" thread, nearly everyone says get the equipment out of the theater itself. I've been struggling to find a good place for the equipment so any input would be appreciated. I've wavered back and forth between cutting out some precious shelving space in the storage area to building a separate bumpout along the theater wall. The diagram right now shows a third idea of building a floor to ceiling kitchen cabinet which could be used to house all the equipment and blend into the kitchenette.

For the theater, the doorway, as I mentioned above, is a single door, but of larger size. Will be solid core and will try to seal it down as much as possible. Placement of the door is set to swing outwards right now to give me more space in the theater.

The measurements are currently stud to stud since the walls are framed already. The windows are very large, but very little light comes in throughout the day. They already have blinds, and adding heavy curtains should do the trick, but custom window plugs are another option I've been looking at.

Here are some of my initial plans for the theater. I'm sure these will evolve as I research further.

Equipment
Things could change by the time I get ready to populate the equipment in the theater, but my plan right now is to take from what I have upstairs to soften the budget blow. Currently that is Athena f2.2s plus matching center and sides. I would like to do 7.1, so I guess I'd have to pick up a couple more to make that happen. I'd like to upgrade at some point to something on the level of Paradigm. Sub is an old Kenwood, which I keep thinking is going to die at anytime, yet it keeps on going. Not that I've really been able to crank the bass since the first baby came along - I think that will be the nicest thing of having a dedicated space.

Projector will likely be something like the Panny AE4000. For a screen, the diagram shows a false wall AT approach, but I really hate losing 2 feet. I'm still up in the air and will likely go the recommended route of getting the projector first before determining exact screen size. Heck, with 2 kids running around, I might just keep a low cost DIY for a while. Right now I'm hoping for a CIH 2.35/2.4 screen about 10 feet wide. I'd like to go wider, but I'm afraid the image will just be too big. Currently have a 67" DLP upstairs.

Seating
Still somewhat undecided here. I'd like to fit as many in the front row as possible because the idea of people sitting behind just feels a little weird. I could see us inviting another family over for movie night and it'd be nice if the 4 adults a a few small kids could fit on the couch comfortably. Ideally I'd like one of those couches where you can fold down a couple of the seats to provide cupholders when the extra seating is not needed.

Looking at other people's build threads, I really, really liked the idea of having a bar with seating at the back that can be used for sports and casual watching. This is where I put in the obligatory 'man I wish I had a couple more feet'. With a 10' wide AT screen, 21+' is just not enough to make that happen from the numbers I've crunched so far. I've even considered eliminating the AT screen to try and fit that back row bar in, but it might just be too forced.

So what I have done for the back row is to split it up. Have a high top table with a few seats and a couple theater chairs. I'm not quite sure the practicality of a setup like this quite yet.

Soundproofing
Master bedroom is above the theater. That's a good thing right now when most of our movie watching is together and no one else is using the theater, but I have a feeling that as the kids get older they will want to use it while we are sleeping. That coupled with the open basement staircase makes me really get serious about soundproofing.

As I mentioned above, my outside walls are already framed. Not only are they framed, but it seems to me that they must be supporting a lot of the joist weight. The joists are not sitting on the foundation edge or anything like that, so I'm not really sure how it's all engineered. Thus, I'm not planning on messing with any of that.

My approach will be the standard clips, channels, DD, and GG. For the ceiling, i have 20" of space I can fill up with insulation, but I've read that anything above R19 doesn't really help anymore from a sound perspective. I'm not sure if R19 + the extra air gap is helpful or not. I'll get around to speaking with Ted sooner or later. Additionally, I plan on possibly adding mass to the 1st level subfloor ala the recommendation on the Green Glue site. There is a lot of tile upstairs and at times it can sound hollow or vibrate the floor when walking around. My hope is that I can deaden the subfloor a bit by applying OSB + GG between the joists.

Not really sure what to do with the windows from a soundproofing perspective. They are double pane, but I'm sure they will rattle, leak, etc. Still need to figure out a plan for that.

Questions

1. I'd love to hear recommendations on equipment closet location
2. What would you do with that weird gap around counter and theater wall?
3. For soundproofing, since the theater wall will already be decoupled by CC on the inside, as well as the fact that its staggered or double stud, should I also go ahead and use RSIC clips to tie into the joists?

Any and all thoughts appreciated.


Edit: Here are some before pictures:

Looking into the theater room.


Upper wall of theater room.


Standing in theater and looking toward bath and storage room.

Reserved for finished theater

Big, thank you for the suggestion. I've seen you scribble on others floorplans so I was hoping you would chime in.

Love the gap and EC suggestions. Probably really was that easy - it just took an experienced eye to go over it. On the EC though, I don't think I want it visible from within the theater. I know some builds have done some really cool and fancy things with display of their components within the theater but I'm not planning on doing anything fancy for the rack and I'd rather not have all the blinking lights nor deal with the soundproofing concerns of opening up that wall. So I would make the rear access the front access and have some sort of pull out option. Let me know if you feel I'm making a mistake here.

Regarding your suggestion to flip the theater, I've considered it before and I am now considering it again. I figured it would be better to have the access to the theater as far back as possible and behind the primary seating position so that entering/leaving the room won't be as much of a distraction. If you flipped it, would you have the door continue to swing out of the theater, or reverse that ?

The other concern in flipping it would be the screen would be essentially even with the bottom window, which would probably necessitate closing those shades more often then if it was in the upper section of the room since there is twice as much wall there.

Speaker placement is not something I've really considered yet, but it sounds like I should. Assuming the ideal positioning is slightly behind the primary seating area, the original design would have had the door in the way (I guess the speaker could be over the door though?). In the flipped plan the side speaker will be above the window. Unfortunately, the top of window is only 11 in from joist and with CC+DD I'll lose a few more inches. I'm not sure if that's enough room for a speaker.

I'll let you guys vote:

Option 1:



Option 2:

This makes sense and is the first time I've heard that it could be a code issue. I seem to remember reading through quite a few builds which use an outswinging (I think that's the term for a door that opens in. Assuming the space outside the theater is considered the "exterior"), so I just assumed it was personal choice. I just checked and my area uses the 2006 IRC codes. I did a bit of googling around and couldn't find much related to inswing/outswing. The only thing I could find was limitations when there was a landing/steps/stairs on the other side.

For anyone going with Option 2, I am still concerned about side speaker placement over the window. There will really only be maybe 7-8 inches or so after CC+DD, plus the speaker would be pegged to the ceiling. What other options would I have for side surround speaker placement?

Note: Added some before pictures to the original post.

The first order of business was to get some storage built to get all our stuff off the floor and out of the way. As I mentioned above, FIL is in town so we made a trip to Lowes this morning to grab some stuff. First time I've wandered around the lumber section of the store.

Had to build the one wall to attach the storage shelves, so went ahead and built the entire frame for the bath and storage room. Not too bad working in the basement today. Much better then working outside as it was 118 today! Next up is finding a place to run some conduit to the first level in order to get some network and coax runs between the floors.

Added some 2" conduit that runs probably about 14ft up to the attic and rests a few inches above the attic insulation. From there it is a short jump over and down to the structured wiring box for the rest of the 1st floor.

At the basement level, I will add in a 90 deg connector and head in the direction of the equipment closet. I must say I was amazed at the sound transfer through the PVC pipe. A little concerned about this since the pipe is above the theater. I think what I'll do is pull the pipe back out and wrap it in something to dampen it a bit before installing anything else to it. A good helping of acoustical caulk around the OSB opening should also help. I'm also considering possibly using a flexible conduit connector instead of the 90deg pvc from the end of the pipe to the equip closet.

On a side note, I did find out that my OSB subfloor was 3 layers thick, which was surprising to me.

To answer my own question, I think my best option at this time would be to use something like an omni mount to hang and angle a speaker which should be placed in front of a window.

I have looked at possibly covering over the windows with drywall or what have you, but the WAF stands as a definite 'No' on that. The most I could go with is a window plug, but if blinds (already there) and heavy curtains can give me the light control (and acoustical treatment) I need, then I won't have to go the plug route.

I should probably mention that my use goal for the room is 70% dedicated movie watching theater and 30% general family use. Having a window or 2 that can be opened up to let just a little light in is desirable. It's also nice to have a little natural light for sports watching and other gatherings. Thus, any ideal solution for me would be something that can easily be reversed for a particular viewing session.

The windows themselves are large, but they are completely below ground and the light that does come through is already pretty diffused, even in the middle of the day.


Logan,
I did consider decoupling the existing framing, but there are a crapload of nails and other metal brackets holding the existing framing to the joists, so to decouple that, cut the studs, and reattach the topplate with RSIC brackets seems like a complete nightmare to me.

Additionally, the joists rest directly on the framing. I don't think it is designed to be load bearing, but it must be supporting at least some of the weight. I will post a picture when I get home to show you what I mean.

Current plan is to use clips/channels on both walls and ceiling.

Here are some more pictures of the window situation to give everyone a better idea. These pictures were taken at 4pm in the afternoon.

From the top looking into the window well.


From the bottom of the window looking up.


No Flash with just the blinds closed.

Here are a couple pictures where the truss joists connect to the rim joist. Let me preface this by saying I don't know jack about construction, but it seems to me that most people have their joists resting on the concrete foundation or a sill of some sort. I'm sure most of the weight is on the rim joist somehow, but just one more reason I'd rather not mess with it even though it's more preferable from a soundproofing perspective to decouple the walls at the framing level.






So this begs the question that I've been contemplating recently about insulating the walls and rim joists. Most here live in colder and wetter climates so they use XPS or some other vapor barrier. My understanding is that my vapor barrier is on the outside of the walls (that black tar stuff) and from reading Building Science, the last thing you want is a double vapor barrier, which all leads up to the fact that I don't need anything on the inside walls. The builder obviously thought this as well as they put the framing right up against the foundation. As far as wall insulation, Building Science has this climate zone chart which indicates a minimum recommended R value for the walls. For me, their value is 0. I'll still probably put some R13 unfaced between the wall studs.

On the rim joist, most here worry about sealing them to keep the heat in. Right now my basement is 80+ degrees. In the winter there are a few weeks that get really cold, but I'm not sure how gung ho I should be about sealing those rim joist crevices up. Thoughts from anyone are appreciated.

Big, thanks for the advice.

I should clarify that most of the framing is not in direct contact with the concrete walls, there is a tiny air gap for most, but where the concrete wall or the stud is bowed a bit, there is some direct contact. Bottom plates do use treated wood though thankfully.

For the foam sealant, do you think Great Stuff would cut it, or should I look into something like Tiger Foam which I hear mentioned here often?

Also on the weight bearing, I don't really know how to tell if something is truly weight bearing or not, but as you say, it certainly looks that way from the picture. However, the wall studs have a lot of give to them so based on that alone, they don't seem like they are holding up that much weight.

The house is just 1 story.

The green rim joist board from the picture (which is from the bottom of the floorplan) looks to be only 1 inch thick, almost like its just a covering sitting on a small concrete ledge. Above those lower basement walls is the middle of the house.

On the upper side of the floorplan, the rim joists appear to be 2 in thick and they look like they are bolted to something with the same bolts used on the bottom plates, so probably concrete behind those rim joists. The upper side walls would also align with the walls of the house.

All of the walls for which the joists are perpendicular have that 2x4 running all the way around like in the picture above. And as you suspected, the gap there is 2".

Pete, Thanks for the input. How common are basements out there in NM?

Your explanation regarding the 1st floor elevation makes sense. Since the trusses are 20" height they need to sink them a bit to maintain a reasonable 1st level step up, which is about 6".

As far as my missing 2", well that's AZ construction for ya. Corner cutting doesn't really surprise me all that much. I guess I'll look at the bright side and take my .001% of less coupling due to those missing 2".

House is stucco with 2x6 walls on the outside. The crevices in the rim joists don't appear to be drafty but that's using the Han D. test - you know the one where I put my hand in front of it and try to determine temperature change. Wish I had a thermal imager.