Add a room to a garage for office\studio

Hello,

I plan on adding two walls to the front left corner of mygarage to create a studio\office that is approximately 14 x 14 1/2. I need to stick to these measurements so thatI can still fit two vehicles in the garage. I already have electrical on the two existing walls and may or may notadd more outlets to the two new walls. Theexisting walls are already insulated, and I plan to insulate the two newwalls. I will just use a portable roomair conditioner and space heater for heating and cooling this small area. I might add a window to one of the existingwalls in the future for a window air unit and sunlight. I plan to just leave the concrete floor so thatI can easily roll around in my chair. I'll also be using a small torch, so carpeting\laminate probably isn't agood idea.

For the two new walls, I assume that I should get treated 2x 6 for the bottom plates, and untreated 2x4 for the rest of the wall framing? Can I attach the two new walls to theconcrete floor with premium construction adhesive, so that I'm not nailing intothe concrete floor? If constructionadhesive isn't feasible, what tool would I need to nail the framing to theconcrete floor? I'm also assuming that Ican just use long screws to attach the top of the wall to the ceiling? For the insulation, I believe that I need tostay with no thicker than 3 1/2 inches?

I will add a door of course to one of the new walls, andwill probably add a window to the wall the will be facing the garage door -thinking I could leave the garage door up if I wanted on occasion to add alittle sunlight to the room. I just needto get a cheap window for this wall - any type or size that I should look for?

I might add a finished room to the attic space above thegarage at some point. However, I'venever been in the space as it's completely closed in.

Thanks in advance for your help!

Welcome to the site. Treated sill plate is a good idea, 2x6 wall for more insulation. The best for a temp wall is a 3/16 hole drilled with a hammer drill a couple pieces of tie will and a 3 inch nail. Two inch concrete nails will work but tend to make a mess out of the concrete when removed. Your window will not need a header so you can use any size you like. When you nail to the ceiling you will want to attach to the ceiling joists, the other wall is a problem. For that wall you can cut a 3 1/2" by 12 hole in the drywall right above the wall so you can slide a 2x4 above the drywall and screw it in place thru the drywall then install the wall attaching it to the 2x4. The engineers where I live get all excited about the fact that a garage floor can move up and down. One trick is to build the walls on the floor with nails, make the walls 1/2 inch short so when you install them and nail up the top plate the studs are not tight at the top which will allow some movement. Depending on where you are you may need vapour barrier, in a cold zone it wants to be on the warm side just behind the drywall. You won't likely have insulation in the ceiling and often the origanal outside wallls aren not insulated.

Welcome
And I agree with Neal go with 2x6 all the way up and add thicker insulation. You didn’t mention how high your ceilings are in the garage. You may not want to go all the way up, but then again you might. I would add insulation to the outside walls somehow. I just added foam board over an old surface and then drywall using extra-long screws and it worked out well.

Post some pictures once you get started sounds like a fun project.

No reason to have a 2x6 sill plate with 2x4 studs unless you are doing to offset method of studding for thermal break.

I agree with nealtw, you may not have any insulation in the garage walls or attic. This is something that you may want to consider if you are planning on heating it up. Also to note, you may have to replace a portion of your roof to install an ice and water shield barrier to the eaves. Most codes state that this must be installed to extend a minimum of two-feet within a heated wall to prevent ice dams when the snow starts to melt. Since this room will be in the garage you might want to check with your local codes, they may also require you to use a 5/8" fire-block drywall on the outer walls of your addition, but you should be ok with using 1/2" on the interior portions of the walls.

Good luck!

Am enjoying the advice you are getting ... all of it very good. Just remember, the garage floor is slanted (by code) toward the front door. All your rolling chairs will go downhill in that direction. More importantly, your framing lengths will change along that 14' run so don't get excited and cut all studs to the same length. Ooops.

I am assuming the garage ceiling is covered with drywall ... if not, you will need to do so to get a complete envelope for heating and cooling.

Before closing up the exterior wall, remember to run new wiring for AC, new demands, and possible communications. Position your 220VAC outlet(s) where they need to be if you get a good AC unit.

Thanks everyone for all the awesome info here! You guys rock!