While dog doors are handy accessories and a boon to busy dog owners, not everyone has the perfect location in which to install one. Installing a doggy door in a wall allows your pet to access the yard wherever you want, so you can keep Fido inside when you want him in and allow him freedom to come and go at other times. There are plenty of door-mounted doggy flaps available on the retail market, but installing one through a wall usually requires a custom job. The deeper opening of a wall-mounted door gives you the option of hanging double flaps for extra insulation and weatherproofing.
Before You Start
Measure your dog to decide the proper size of door to purchase. Find the rise, or step-over height, first by measuring the height from the bottom of your dog’s chest to the floor. Next, get the maximum height for the door by measuring your dog from floor to shoulder. Your dog‘s widest measurement at the shoulders, hips or belly determines the opening's minimum width.
Purchase a commercial self-framing pet door designed specifically for wall installation using your measurements as a guide.
Consider purchasing an electronic multipurpose detector to locate wires and plumbing at the same time. Cutting through wires and pipes could prove serious if not deadly.
Inside the House
Use a stud finder to determine the stud spacing in the wall in the exact spot where you will install the pet door. Most houses use standard 16-inch-on-center spacing -- meaning that the center of each vertical stud is 16 inches away from the center of the next stud -- but that measurement may vary. If you have a multipurpose detector, scan the area with it to find hidden hazards.
Draw a rectangle only slightly larger than the pet door on the wall between the studs, at the correct height for your dog. Use a carpenter’s square to ensure straight cutting lines.
Don safety glasses and ear protection.
Employ a jigsaw or drywall saw to remove that section of the gypsum board or other wall covering to expose the framing area.
Remove any wall insulation or debris within the opening.
Measure and cut 2-by-4-inch boards to fit horizontally between the vertical studs -- one each for top and bottom. Refer to the recommendations in your pet door instructions for the exact size you'll need.
Nail scrap blocks of 2-by-4 above and below on each side of the cutout area -- stopping 1½ inches short of the exact measured area for the door. These will act as nailers for the horizontal boards.
Position and screw the horizontal framing members to the nailer blocks with 3½-inch-long wood screws.
Measure, cut an attach additional blocking on the sides, as needed, to reduce the width of the opening to the correct size for the dog door.
Test-fit the interior portion of the pet door within that framework before proceeding to the exterior of the wall. Make adjustments as necessary.
Use a small bit to drill a pilot hole inside each corner of the pet door framework -- all the way through to the exterior wall -- from the inside of the house. The four holes will mark the corner locations of the door frame on the outside of your home, and serve as guides for cutting away the exterior siding.
Outside the House
Locate the four holes you drilled from inside the house and remove only as much siding or veneer from the exterior of the house in that area as necessary to easily access the sheathing beneath.
Using your pencil and carpenter’s square, draw a rectangle -- still using the holes as a guide to prevent cutting into the 2-by-4 framework -- on the newly exposed sheathing.
Rough-cut the hole using the jigsaw, then carefully trim the opening, as needed, to fit the frame precisely.
Install the pet door according to instructions in your pet door kit.
Replace the siding or other veneer around the door, add trim as needed and use a caulk gun and a quality exterior caulk to seal any seams.
Do not cut through wall studs. If the space available between studs is too small to cut out a suitable opening without cutting through studs, or if there are wires or pipes in that area, find another location for the pet door.
Be aware that pet doors can pose a danger to young children. The Consumer Product Safety Commission has received a number of reports indicating a rise in accidents involving toddlers using pet doors to leave the house unsupervised. These mishaps often involve swimming pools and other hazards accessible through unsecured pet doors.
Some houses use 2-by-6-inch framing or larger. Check before purchasing a pet door or lumber and adjust the pertinent measurements accordingly.
Items You Will Need
- Tape measure
- Self-framing pet door, with manufacturer’s installation instructions
- Multipurpose detector - optional, but strongly advised
- Safety glasses
- Ear protection
- Stud finder
- Carpenter’s square
- Jigsaw or drywall saw
- 2-by-4 lumber
- 16d common nails
- 3½-inch wood screws
- Exterior trim, optional
- Caulk gun, optional
- Exterior caulk, optional