How to Repair a Hole in an Interior Door

Interior doors are usually lightweight torsion boxes made from thin sheets of MDF glued to a light wooden frame and separated by a honeycomb of cardboard. They're easily damaged, and during a recent party at our house, a couple of holes were kicked in a bathroom door. I have fixed such impact damage before, but idly searched for how to repair them anyway and found that the how-to's on this topic all seem to use expandable foam AND automotive body filler AND plaster (e.g. Bob Vila, wikihow, instructable). Expandable foam is great BUT you can't keep an opened can of it around for long before it seals itself up (and yes, I have taken all recommended precautions). And it's not really necessary, nor is the autobody filler. Here's an alternative way to do it that is easy, inexpensive and lasts just fine.

Materials: Door with a hole punched in it, drywall plaster, drywall screws, and construction adhesive.

Tools: drywall taping knife, cordless drill, sandpaper, hammer or catspaw

Drive drywall screws into each piece of the hole. Drywall screws are very sharp so this is easy, but obviously the pieces of door are fragile so take care. You're going to use the screws to pull the hole roughly back into shape. Before you do, squirt some construction adhesive along each of the broken edges, and smear it in. Construction adhesive is good at bridging gaps, so it performs well here. Gently pull the pieces outwards. There will be some resistance, because the cardboard behind is crushed, but don't pull too hard or you'll risk ripping the hole wide open. Find the rearmost piece and hang a hammer or catspaw from that screw - the weight of it will pull the hole flat while the glue dries. Leave it overnight.

Note that if the hole is really big, go for the more elaborate expanding foam approach linked above.

Remove the screws. You should have gone from a deep puncture to a shallow depression. Sand off any raised pieces (I used a pole sander) and add your first coat of plaster. Leave to dry. You'll get some shrinkage because the first coat is always the thickest. Add a second and if necessary a third coat, sanding between layers.

Paint the patch in the door its original color. You're done.

I've made this exact same repair for other damaged doors in the past, and it holds for years without any issues. Good luck if you decide to try it out, hopefully I save someone out there some unnecessary hassle!