Pet Doors for Doors FAQs
Does it matter if my door is hollow core rather than solid core?
It used to matter a lot. In the old days pet doors consisted of a frame and flap assembly for one side of the door and sometimes, but not always, a decorative trim frame for the other side.
These worked fine in a sold core wood door (though you did need to seal the exposed wood if you didn't want rot). If you wanted to install one of these in a hollow core door, you had to "frame out" the door first so that the weather didn't get inside the door between the two pet door frames. Of course, the lumber yard didn't have any wood that would fit inside the sides of the hole that you cut so you needed a table saw to fit the frame pieces. It was a huge hassle.
Then Pet Eze Company developed a pet door where the outside frame wrapped through the hole in the door to meet with the inside frame. All you had to do was caulk the seam between the two and you were done. No framing or sealing needed!
Today nearly every pet door on the market is self-framing though not all and you should remember to check especially if your door is hollow-core.
Why else might I want to use a "self-framing" pet door?
An important reason is that the job ends up neat and clean. If there are any jaggies in the hole you cut, no worries. You won't see them because the pet door framing will hide them.
Does it matter how thick the door is? I want to install my pet door in a storm door that is thinner than a normal door.
Every self-framing pet door has an adjustment range that indicates the thinnest door it can be installed in and the thickest. Go too thin and the pet door framing prevents a tight fit. Go too thick and the inside and outside frames don't meet. So measure the thickness of your storm door and make sure that figure is inside the range of the pet door you are considering.Each self-framing pet door on this site shows this adjustment range.
Note that you can always shim out the opening if the door is too thin. Clever work with a router can fix the case where the door is too thick.
How thin can the material I install in be? Can I put it in the kick panel of a screen door?
Nearly every self-framing pet door will fit the "standard" interior door dimension (1 3/8") and the "standard" exterior door dimension (1 3/4"). A few high-end exterior doors now are 2 1/4" and a few pet doors will accommodate that. Likewise, many pet doors will adjust to quite thin dimensions. Several cat doors start at zero! (They are designed with a tunnel extending from the read of the flap assembly and a trim frame that slides down that tunnel until it stops).
For your screen door kick panel the ideal adjustment range would go to zero since your metal may be a little less than 1/16". If you need to, of course, you can use thin shims around the hole you cut to get the necessary thickness. Be sure you leave enough door framing top and bottom for the strength of the door.
Does it matter that my door is steel or aluminum?
If we were discussing electronic pet doors then it might very well matter but this section is devoted to manual pet doors and they don't care what the material is provided it's strong enough to provide the necessary support.
The door I want to install a pet door in is a fire door
The pet door won't care but your insurance agent might. Check with him first.
I want to install in an irregular surfaced door. Is any pet door designed for that?
No. Every pet door wants to be installed on a flat surface. Or, at the very least, the four corners must be at the same level with nothing thicker in between. Our installation problems page shows one solution to his problem. If that looks like too much work then you can cut the hole so that 2 or 3 corners are on the same level and use shims to bring the remaining corner(s) up to the same level. If you've used a self-framing pet door then a bead of caulk inside the frame along the low spots will make the seal tight. Caution: It's best to use a pet door with a flexible flap whenever there's a chance that the surface isn't perfectly flat. The reason is that rigid flaps can easily bind in their frames if there is any mis-alignment whereas flexible flaps are more forgiving.
Any special thoughts about installing a pet door in a garage door?
Everything above applies to a garage door installation as well. Your garage door is probably hollow and may be thinner than an ordinary door so, again, use a self-framing pet door and be sure the thickness is inside the adjustment range. Deal with any irregular surface and be sure you leave enough of the garage door top and bottom so as not to weaken it.
That said, there's one issue that comes up only with garage doors. If you've installed a flexible flap pet door, the flap is probably going to hang down when the door is open. If you leave the garage door open for long periods, the flexible material is likely to take a "set" and not seal well when the garage door is closed. This is particularly true of the cheaper pet doors that one naturally thinks of for a garage. This problem disappears with a rigid flap pet door or a flexible flap one that has magnets strong enough to keep the flap shut even when tilted flat.
A final thought: It's not so hard to injure or kill a pet by backing over him. Unfortunately, we know of cases where this has happened. Please don't install a pet door in your garage door unless you've got a fool-proof plan for avoiding this tragedy.
Any other important points?
Yes. First, use a level. You want your flap to swing parallel to the ground. Second, plan carefully the height at which you are going to mount the pet door. If you're having a handyman do it for you be sure to supervise him because he won't know the correct height. More information on this point is at measure your pet.