Shortening a hollow core interior door

Old 01-03-21, 07:45 PM
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Join Date: Sep 2013
Location: Canada
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Shortening a hollow core interior door

I'm finishing my basement which includes the installation of three interior doors. I'm in Canada and selection is sparse these days. I decided to go with the same hollow core interior doors that exist in the rest of our 1965 house.

The basement it basically split into three areas. A utility and work area that is unfinished. A finished rumpus room... and a bathroom. The bathroom features a massive tub that my wife insisted on. As a result I needed to extend the room under an air duct and resulting low bulkhead. I needed a 74" door.

I was blown away that nobody builds pre-hung doors for basements... At least not around here. Not even custom. Perhaps it's not code or something.... I'd have figured even the door manufacturers would be smart enough to add some extra top and bottom structure so the doors could be shortened. NOPE! It appears everyone slices off the bottom of the door and either drives themselves crazy trying to pry out the bottom to glue back in.... or they rip a new piece altogether.... To me, both options seemed a PITA for what would be nothing much more than stopping stuff from getting up in there....

Searching Google and Youtube it was more of the same. Nada..... Everyone I could find did the same thing. There had to be a better way

OK, check this out.... Nobody is looking under the mounted door.... I sliced the door down with a circ saw on a clamped track exposing the hollow emptiness....The way everyone does. Then I clamped two levels on either side of the door.... (stay with me, it's to prevent bowing) I filled the cavity with a liberal amount of Great Stuff foam insulation. The area itself was covered well with painters tape so the expanded foam wouldn't make a mess later. Once cured I used a utility knife to slice off the excess.....

The foam is solid and secure.... and it was easy! Spray foam is incredibly secure and will handle a lot more than this.

I hope this helps others.

Note that in these pics I'd already removed the clamps and painters tape.

2john02458, cartman voted this post useful.

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