Pass-through garage door

Problem

We wanted to place the garbage cans in the driveway rather than in the back yard – but the path from the kitchen to the driveway to throw out the garbage goes through the garage. We were afraid that operating the garage door much more often, each time we took out the garbage, would eat into its lifetime. So, how do you go through the door without opening it fully? A pass-through door within a door.

Solution

At first I was sure I could buy such a door-in-a-door without a problem, but that was not the case. First problem: all standard doors you can buy are taller than our one-piece garage door, so they would not fit. 

You can buy custom-made garage doors with built-in walk-throughs but they cost a fortune. Here's the principle (click to see a video):

So I made my own for about $50 in materials and a few hours of work, following these steps. Here's what my door looked like before I started – it is a one-piece door made out of 7" slats held together by 2x3's:

1. Draw the outline of the future door, making sure you leave a few inches on the bottom below the future opening. To protect the garage door's structural integrity, don't make the opening larger than necessary

2. Cut through the outline you just drew, leaving a couple of places on each of the 4 sides not cut for the time being – you will do the final cut later. You can use a rotary saw or, as I did, an oscillating multi-tool.

3. Place a frame made out of 2x3's inside the cut, and another one outside the cut. Screw these 2x3's into the slats that make up the garage door from the inside, using 2" screws.

4. Screw hinges between the outside (fixed) and the inside (mobile) 2x3s. On the side of the door opposite the hinges, screw a temporary strap between the future door and the fixed 2x3.

5. With all the hinges and the strap in place you can now go ahead and finish cutting completely the perimeter of the door opening without any worries. Remove the temporary strap and check the result. You may have to do some final sanding. Also to make sure the door stays well closed, install a ball catch in the bottom of door and sill.

Here's the final door, seen from the inside. Note that the vertical 2x3s of the Fixed Frame are also screwed, top and bottom, to the top and bottom plates of the garage door to prevent movement. I used a self-adjusting latch to finish the job.

Oh- by the way- surprise when the job was finished: the garage door motor would no longer lift the door!!! Sounds bad but fairly easy to fix. 

Turns out all this added 31 lbs to the door. So I replaced the springs with the next size up: Holmes Spring was model P728 and was ready to replace anyway; replaced it with P528.