Fenestration questions

[zahc]

I want to cut a hole in my garage wall and put in a window. The ulterior motive is to install a window AC unit. The house exterior is cement plank sided. Do I need to buy a "new construction" window or a "replacement" window? I'm hoping to not have to remove any siding planks. I have a good blade for cutting thd siding though.

The studs are 16 on center. Original plan was cut out 1 stud and install window between remaining studs. I would have thought there would be a size that fits in such a space between studs, but I can only find 28 inch (which will need a shim stud installed) and 32 inch (which just barely won't fit) and 36 inch (definitely won't fit; might as well take out another and go to 38 at that point). This is annoying. I guess it's 28 inches for the win. Is a double-2x6 header enough for a load-bearing wall for supporting only one stud?

Single-hung is cheaper. Will I regret not getting double-hung?

[just Warren]

Single-hung is cheaper. Will I regret not getting double-hung?

I know of this bar in Bangkok...but yeah you're gonna pay extra, a lot extra.

[AmbulanceDriver]

Your opening from removing one stud is going to be 30 1/2". Add in two jack studs to support your header and you're going to be at 27 1/2" rough opening, unless I'm doing my math wrong.

[zahc]

You may be right. I'm probably going to have to remove 2 studs anyway so then it doesn't really matter.

[Hawkmoon]

Your opening from removing one stud is going to be 30 1/2". Add in two jack studs to support your header and you're going to be at 27 1/2" rough opening, unless I'm doing my math wrong.

Your math is correct.

You need a new construction window. "Replacement" windows are made for removing the two sash from an existing window and putting the new "replacement" window into the remaining frame of the original window. I hate them -- you end up with a smaller glass area, a smaller ventilation opening, and they just look ugly.

A double 2x6 header is fine for a single window.

Here's a diagram of what the framing should look like, with one exception:



The exception is that in this diagram they used several cripple studs under the rough sill, because it's a wide opening. For a smaller opening, you may need an extra cripple or two beyond what's needed to maintain the 16" spacing, so that you have at least two studs under the rough sill to keep it level.

[zahc]

Do the king studs on each side have to go all the way up to the top plate?

The garage is on a slab whereas the house is on a crawlspace, so the garage walls are like 12 feet tall.

I can re-use an existing stud as a king stud for one side, but I can't add a king stud on the other side that goes all the way to the top, without totally pulling out a lot more drywall than I was hoping to pull out. I can still add a jack stud+"king" stud support pair on the other side to support the header though by finagling it into the window opening.

 

[Hawkmoon]

Do the king studs on each side have to go all the way up to the top plate?
 

Yes.

And you can't "finagle" a king stud into place. It has to be properly nailed into the top plate. You can't do that through sheetrock. IMHO you'd be better off to make you opening wider, occupying three stud bays. That allows plenty of room for jacks and cripples, and you'll automatically have two cripples under the rough sill.

[zahc]

Ok I guess the header will be wider than the window at that point but I don't see the harm in filling in the space with a scab stud to reduce the hole width.

[RoadKingLarry]

You're going to have to open up the inside pretty good anyway. Make the framing rough opening big enough to use existing (original) king studs then once you have it done like the above illustration frame in the opening for the window size you want. The opening on the outside doesn't have to or need to match the framing on the inside.

[Hawkmoon]

Ok I guess the header will be wider than the window at that point but I don't see the harm in filling in the space with a scab stud to reduce the hole width.

You said it's a bearing wall. Doing it your way, you'll have a header with at least two jack studs bearing on it, and it won't be anchored to anything on one end. It's unstable -- it'll act like a hinge. Two years ago a property manager client paid me to design a repair for a condo that had a hinge built into the end wall. It wasn't even load bearing, but in winter the wall bowed about three inches out of plumb at the hinge. The repair cost the condo association big bucks.

[KD5NRH]

Another option if you can weld is to replace a few studs and the rough framing with structural steel tubing. Beware, though; structural tubing is true to dimension, so 2x4 means 2x4. However, you can change wall thicknesses to get nearly any amount of strength you want and thus give yourself lots of options for the opening.

[Jamisjockey]

Skip the window and just mount the AC through the wall.
Or better yet...
http://www.mitsubishicomfort.com/?gclid=EAIaIQobChMI9-qZ-PGH3AIVwx-GCh0kDAPgEAAYASAAEgKhJfD_BwE

[dogmush]

Jamis beat me to it.

If the goal is to put an AC in, hang a split unit on the wall and be done with it.  You can get a 1 ton split for under a grand, and save yourself quite a bit of time and effort by skipping the window.

[charby]

Jamis beat me to it.

If the goal is to put an AC in, hang a split unit on the wall and be done with it.  You can get a 1 ton split for under a grand, and save yourself quite a bit of time and effort by skipping the window.

X2

[K Frame]

With some of those split systems you also have the option of heat.

You'll spend a couple thousand on having one of them installed, but you won't have the expense or effort of opening up your wall and hoping that you get the framing A) correct, and B) beefy enough to support the roof load.

[Jamisjockey]

With some of those split systems you also have the option of heat.

You'll spend a couple thousand on having one of them installed, but you won't have the expense or effort of opening up your wall and hoping that you get the framing A) correct, and B) beefy enough to support the roof load.

IMHO a smaller one can be DIY installed especially when we're talking a garage.
Check Youtube for videos on it.

[K Frame]

Hey, you can buy a single unit heat/cool from Walmart!

https://www.walmart.com/ip/MM09YJ-30-Wall-Mounted-Ductless-Split-System-Heat-Pump-9-000-Cooling-BTU-s-9-800-Heating-BTU-s-Optimum-Air-Flow-Continuous-Air-Sweep-Auto-Restart-Inv/121450893?wmlspartner=wlpa&selectedSellerId=2268&adid=22222222227049907825&wmlspartner=wmtlabs&wl0=&wl1=g&wl2=c&wl3=147481932618&wl4=pla-263807662235&wl5=9008148&wl6=&wl7=&wl8=&wl9=pla&wl10=113139806&wl11=online&wl12=121450893&wl13=&veh=sem

[zahc]

I considered the split unit.

0. you have to run new wiring for a split unit. There is no true DIY if I have to involve an electrician. I can do the wiring myself but if I need to get permits it's still a pain.

1. no local companies will install one because for one thing they aren't familiar with them and nobody wants to do anything they aren't familiar with, for another it doesn't meet HVAC code, so they claim, to install in the garage which is not a living space. They have load calculations that they have to comply with in order to meet a minimum standard which includes something like keeping the space at 70 degrees on a 110 degree day. Air balance or something. My goal is only to bring the temperature and humidity down to non-sauna levels. I don't need to preserve flowers. But they won't take the job because codes. One guy who would, quoted me $4k. My own load calculations show 12,000 btu should be plenty. A 5k window unit may be enough.

2. The HOA may or may not allow a split unit. They have a rule against "through the wall air conditioner" whatever that means. They also have a rule against window units but if I get caught with a window unit it's not too painful for me.

This is how I arrived at my idea of installing a window, and sticking a window unit in. Then if the HOA get picky I get stuck with a window I might not have otherwise installed, but that's all. I could also use one of those sucky portable AC units even then.

[Hawkmoon]

I considered the split unit.

0. you have to run new wiring for a split unit. There is no true DIY if I have to involve an electrician. I can do the wiring myself but if I need to get permits it's still a pain.

Unless your state or county has some weird regulations, you need a permit but you don't need an electrician to do electrical work in your own home. The permit is just to ensure that it gets inspected for safety. As for the garage, right now it's outside the "thermal envelope" of your house. If the permit department tries to invoke the energy code and make you upgrade/extend the thermal envelope to include the garage, I would use the argument that the garage is not living space, and that the a/c will only be used occasionally, when you're working in there. Since it's normally a non-occupied space, I think it can be exempted from the energy code.

What about a portable? They do require a discharge vent, but it's not a through-wall unit. The discharge vent can be placed close to the ground or behind a plant, and covered with a flat louver to look like a dryer vent or just an intake louver.

http://www.toptenreviews.com/home/hvac/best-portable-air-conditioners/

[Ben]

What about a portable? They do require a discharge vent, but it's not a through-wall unit. The discharge vent can be placed close to the ground or behind a plant, and covered with a flat louver to look like a dryer vent or just an intake louver.

http://www.toptenreviews.com/home/hvac/best-portable-air-conditioners/

My only option for many years was a portable. When I lived in my condo I had a West facing office where I spent a lot of time with several computers running. It was always hot in there. HOA would not allow window units (without going into it, I can't blame them in this instance) so the portable was my only choice.

They do put out a good amount of cold air and the good ones are quiet. You need to check that your wall socket will handle the amperage on some of them. The big drawback to them, IMO, is that damn vent hose. Heat has to go somewhere, and while much of it goes out the vent, the rest of it builds up in the hose, and the thin-walled hose is actually radiating heat as the AC is cooling. When you shut the AC off, your cold air immediately ceases, but the hose continues to radiate heat for a good while, counteracting all the work the AC did.

I guess you could wrap that vent hose in insulation of some kind. I never did because it would have made it even more bulky and a pain to move, which is supposed to be one of the advantages of a portable. Mine was not an el cheapo either - it was a ~$700 LG.

[Firethorn]

A split would be more powerful and efficient.  Probably easier as well.  Lots of work to put a window in.

[zahc]

I still need some sort of vent (window) to run a portable. I'd rather put in a window than cut a random vent hole in the wall. Plus portables are expensive per actual BTU, plus they take up space I don't have.

Energy star recently smacked down the portable AC companies because they were stating the BTU capabilities of the cooler but not taking into account the impact of the hot side on the room, nor the impact of the single hose models sucking warm air back in by creating negative pressure. I think basically if they put the new requirement, all the portable unit BTU ratings are going to be half what they are now. Which based on my experience seems about right. BTU for BTU it seems like you need a 10k portable to equal a humble 5k window unit.

[KD5NRH]

Any rule against a through-the-wall dehumidifier?

Then a Port-A-Cool will work.

[charby]

Probably going to need a permit for a window, since you are making structural changes.

Weird that your HOA doesn't allow ductless air conditioners but still allows central air? Both have units outside.

[Hawkmoon]

Probably going to need a permit for a window, since you are making structural changes.

Good point. Technically, a permit is generally required even if the changes aren't structural. There are several different code sections that apply to windows, plus the exterior weather envelope is regulated, so any changes to that are also regulated.

Getting back to a question from the opening post that hasn't been discussed:

I'm hoping to not have to remove any siding planks. I have a good blade for cutting thd siding though.

I don't think it's possible, the way most windows are made today. With an old, wood window that has a real brick mould for perimeter trim, you would have cut back the siding an inch and a half (or so) beyond the rough opening, to the exact size of the outer dimensions of the trim, install the window, caulk, and be done. It's almost impossible to find a window like that today. Most have a nailing fin that's both the mounting and the flashing. The design is intended for the siding to then lap over the nailing fin. There's no good way to do without removing or cutting back and patching the siding.

I did see a guy do it otherwise, once. The assistant pastor at the church my late wife and I attended had a second floor apartment with a habitable attic. He was renting it to a woman with a bunch of kids, and they were using the attic as a bedroom. It didn't have a legal escape/rescue window, and I was concerned that if something happened, the padre would be liable because he had allowed kids to sleep in an illegal bedroom. I bought a window at Home Depot, and a member of the congregation who is a home improvement contractor volunteered to install it. I met him at the padre's house on a Saturday morning with the window and watched him work. The first thing he did was cut the nailing fin off all four sides of the window.

"Now what are you going to do?" I asked.

"I just screw the sides to the rough opening," he said. "Simple."

"And what about flashing?"

"Ummmm ...."

So I went back to Home Depot and bought a roll of aluminum flashing stock to fabricate something to replace the fin that the idiot had just cut off. We used that on top, but on the sides he just loaded it up with caulk. Which might be okay for a year, maybe two. Once the caulk dries and shrinks, it's useless. So you need to remove siding far enough beyond the rough opening to have a place to nail the nailing fin, then you replace the siding to overlap the fin.