Sliding Glass Door Wood Frame Rough Sizing

french-door-before As part of our ongoing rental property renovation, we’ve decided to replace the old sliding glass door with a new, upgraded slider. The old door (pictured right) is original to the house and 22 years old. Over the past few years, its grown harder to open as the house settled and the door began to wear out. About 2 years ago, the renters’ dogs damaged the screen and it had to be removed (their security deposit covered this).

To save some cash on the replacement, we decided to tackle the installation ourselves. So far, the project’s going great. This article covers the first few steps in the process: removing the sliding glass door and ensuring the rough in opening is right-sized for the replacement.

Remove the Sliding Glass Door

The first step in our project was to remove the existing glass door. Every sliding glass door works a little differently, but most share a common removal method: the doors lift up and out of the track, usually towards the outside of the house. In our case, we had to remove some set screws at the top and bottom of the fixed door. Once removed, the fixed door lifted out easily. Once the fixed door was moved, the sliding door easily lifts out behind it.

Remove the Slider Frame

Once the door is removed, the slide frame must be removed. In our case, the frame was actually secured from the studs in towards the door at the base and top of the frame. This made it incredibly difficult to remove the frame. We ended up removing it destructively with a hammer and pry bar. The key in this step is to try to avoid damaging the rough-in opening and and siding or J-channel around the edge.

Rough-in Size for Sliding Glass Door

Once you’ve got the existing door removed, check the size of the rough-in opening. Most sliders in townhomes are 72″x80″. In our case, the existing door was 74″x82″ (a non-standard size). The recommended rough-in size for our new door was exactly 72″x80″, with a door size of 71.5″x79.5″. If the rough-in is too small, you’ll need to custom order a door to fit in the space. If the rough in opening is too large (as was in our case), you can frame in the gap with wood. We chose pressure-treated wood for added durability, although regular studs would have been fine.

Frame in from the Top and Sides

wood-frame-for-patio-door Add wood to the top and sides of the frame, but not to the bottom (otherwise this would become a tripping hazard). Ensure that the rough-in opening stays larger than the recommended rough-in size for the new door. Make sure that the wood joins at right angles.

Tip 1: Measure the rough-in opening from one diagonal to the other (top-left to bottom-right, then top-right to bottom-left). If the numbers match, the door is square.

Tip 2: Measure horizontally at the top, middle, and bottom; then measure vertically at the left, middle, and right. All of the horizontal measurements should be the same, as should the vertical measurements. If not, you may have a warped wall, ceiling, or floor. A small error can be corrected when installing the door itself.

Tip 3: Fix the rough-in before fastening tightly. Don’t put a lot of fasteners (nails or screws) into the frame until you are confident the frame is perfectly square.