I am considering building a small 6 x 9 room inside my garage to use as an office. However, I do not want to remove the garage door opener unit nor the tracks the door slides on because we will want to continue using that door for access to the garage.

I have seen a few resources with guides for framing but all show the top plate of the room being secured to an existing ceiling. In my case I want the ceiling to be independent.

Also, the height from the floor to the garage door slider tracks is 8 feet. With some play I am thinking I will be OK with a 7 foot ceiling but I am not too thrilled with a ceiling that low. Any creative recommendations for dealing with garage door sliders?

  • Why can't you put your room in a back corner of your garage where there are no door tracks ?
    – Web
    Jan 25, 2011 at 19:49
  • Good question. Because the side we do not park on (where I will build the room, the car does not fit on the other side) has stairs leading down from the house into the garage. In order for us to get to the car from those stairs means the room has to be partially under those tracks. Sucks but I don't think there is another way unless the room could be 6 x 3. Jan 25, 2011 at 20:19
  • Do you need a ceiling? why not leave it open. just build three walls, tie them into the original wall, and fasten them to the floor. (and don't forget a door).
    – Tester101
    Jan 25, 2011 at 21:58
  • I need a ceiling because I live in Maryland. It gets both very hot and very cold. Jan 26, 2011 at 2:18

2 Answers 2


You are essentially building a self-supporting flat-roofed shed inside the garage, not adding interior walls to the garage.

You should be able to screw a 2x4 sill plate onto the garage floor. The sill plate is mostly there in case the concrete is uneven. It could be pressure-treated in order to resist rotting from moisture on the floor or in the concrete. (In that case, use galvanized nails to nail the sole plate to it.) If you don't build a floor, I think the sole plate of the walls could be screwed directly into the floor, avoiding the sill.

Since you're in a cold climate, you may want to build and insulate a floor. If so, place the rim joists, then hang the remaining joists with joist hangers, insulate, then glue and nail on plywood sheathing. If the joists go in the short direction and are spaced 16" o.c. you should in theory be OK with 2x4 joists, but the code may require 2x6 as a minimum, and that would leave more space for insulation.

Next, frame the walls individually, sheathe them with plywood or OSB, and raise them. If you have a sill or subfloor, face-nail the sole plate to the floor with 16d nails 16" o.c. Sheathing the walls adds lateral support, and thereby helps keep them square. This is a lot easier to do while the walls are still flat on the floor, before you raise them. Make sure to double the top plate.

Finally, frame an "attic subfloor" as a ceiling for your office. In response to your question, the ceiling is somewhat similar to a wall, but the joists must be hung properly (not just end-nailed like the studs in a wall), and the sheathing (plywood or OSB) needs to be glued as well as nailed. Sheathing this subfloor is essential for stability. As mentioned, if spaced 16" o.c., 2x4 is sufficient to span 6 ft, but your code may require 2x6 anyway.

Check out the framing books at the home improvement or bookstore, or google for "framed floor" and "platform framing". Check your building code for insulation requirements. You will probably need a building permit.

The ceiling height may be an issue, once you subtract 6 inches for a floor and 6 inches for a ceiling.

  • You have the idea. Why sheathe the walls before framing? Jan 26, 2011 at 15:59
  • Also, I was planning on just having the garage concrete floor remain as the floor of the 'shed'. Do I need both the sole plate and the sill plate? Couldn't I just secure the sole plate of each wall to the concrete? Jan 26, 2011 at 16:07
  • Thanks for the info. I am thinking of doing no sill plate as the concrete is pretty flat and even. Can I use pressure treated wood as the sole plate and just screw that into the concrete with tapcon screws and washers? Finally, I am wondering about the "attic subfloor" you mentioned. I did some googling but could not find any mention of this term. Is it essentially just another wall placed on top of the structure (2x4's and plywood sheathing)? If so, good, as I was planning on insulating the ceiling so this seems to be a good solution. Jan 26, 2011 at 23:22
  • @phirschybar: I incorporated my answers to your comments into my main answer, as they were too long for comments. Jan 27, 2011 at 10:06
  • Thanks again for helping. I am curious about your take on the flooring (or lack of). I don't think this project will be possible if I need to insulate the floor because my ceiling height will end up close to 6 feet (way too low). How necessary do you think it is? Jan 27, 2011 at 14:12

This solution would mean replacing the garage door, which perhaps is not in the cards, but there are "roller" doors that roll up above the garage door opening, such as those pictured here: http://www.buydoorsdirect.com/

That would eliminate the tracks as a factor, and you could build all the way up to the existing ceiling.

  • Is it not structurally sound to not connect to the ceiling? I will be able to brace the structure to one of the walls of the garage. I don't think I can afford to replace both of the doors wih roll ups. Jan 26, 2011 at 2:26
  • 1
    I think the structure would be fine as you described; I was just pointing out one way in which you could eliminate the problem of the tracks and not worry about a low ceiling.
    – Jay
    Jan 26, 2011 at 2:47

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