THE MULLIGAN

To build the pop doors, I first cut an old piece of 1x6 PT board for a sill plate.
The width of the sill plate was equal to the width of my pop door opening: 10".
The exterior portion of the sill plate was extended out on either side of the opening by the width of the 1x2 trim, so 3/4", and I added another 1/2" to that.

The pop door framing sides are routed out 2x lumber that I ripped to 2" wide. The routed slots are 1/2" deep and about 1/8" wider than the plywood door. I used my table saw to route the slots.




I ripped two strips of lumber and screwed them to the tops of the slotted wood to finish the pop door framing.



I positioned my pop door frame about 7" above the coop floor. I placed a torpedo level on the top of the frame to ensure it was level then traced along the inside of the framing to mark the coop wall where I needed to cut the hole for the door. I added the thickness of the sill plate to the bottom of the traced lines. I drilled a 1" hole in opposite corners and used a sawzall to cut through the coop wall.

The sill plate was inserted through the opening and tipped towards the outside of the coop before pilot drilling two holes straight down through the sill plate and into the center of the T1-11 sheathing. I countersunk the screw heads and covered them with some painters caulk. I reinforced the sill plate with metal angle brackets that I already had on the inside of the coop. This could just as easily been supported with a ledge board attached to the sheathing and then the sill plate.

I then set the pop door framing level with the top of the sill and screwed the framing to the inside of the sheathing from the exterior and dropped the door in place. The screws are covered with the exterior trim.


Below is a cross-section sketch of how the pop door was constructed and installed.


The solid green is the sheathing.
The framed green is the hole through the sheathing with solid sheathing in front of the framing.
The grey is the angle bracket.
The blue is the side framing and the two top strips that hold the sides together.
The black lines are the screws.


Because I rarely close the pop door, I just used a cord tied to an eye screw at the top of the door to pull it open then tied the cord off on a rope cleat. I screwed two pieces of scrap lumber to the inside of the wall to act as stops to keep me from yanking the door right out of the framing.