Interior passage/Bedroom Doors

[George Denecke]

We downsized 2 years ago & I finally got to putting oak thresholds in the bedroom doorways. Since nature always sides with the hidden flaw, I didn't allow for the height of the thresholds &, of course , the doors won't close.
My easiest solution is to trim the bottom of the doors. The question is "How much can I take off??"  The woodwork in the house is modestly old & the doors seem to be the basic, flat hollow core birch from mid to late 20th century. I'll start with 1/2 in off.
Along the way I'll have to trim the edge of the hallway carpet under the threshholds. Is there anything to do this other than a utility knife, straightedge and elbow grease................TIA......George

[fredhargis]

I've seen a fair amount of carpet installed and never saw the pros use anything but a utility knife. They ones they used were different in shape (kind of a rectangular blade instead of a trapezoidal shape) and I suspect they are available at any of the box stores. That said, my own limited work with this was just the everyday type, and while you go through a lot of blades it seems to work well. As for the door, the one time I checked the thickness of that filler strip around the edges it was on the order of 1 1/2"....but if your nervous about it, you could drill a small hole and check it before cutting.

[Willyou]

1 1/2" could be right. If you tap tap tap on the surface with your finger or something like a screw driver handle, you can find a good approximation of where it is from the sound and feel. Start with that and if it appears to be close to where you need to cut, drill the hole that Fred suggested.

May I ask why you need/want the thresholds? Usually, if the flooring is the same in both rooms, a threshold is not needed.

I'm not sure I understand what you mean by "trim the edge of the hallway carpet under the thresholds".

[lift mechanic]

When you trim the bottom of the door. Apply masking tape to both sides of the door where it will be cut. This will keep the splintering to a minimum. You can also score the cutoff with a utility knife before cutting with a saw. Most doors I have trimmed have about 3/4" to 1" solid wood on hollow core doors.

[Bill Wilson]

Is it possible that the doors were already trimmed once, upon the original installation?  If so, you may not have as much material in the bottom as you expect.  Not a big problem though.  If you cut the entire frame out to the bottom, it's easy enough to replace.  Just rip a new piece out of some 2X material.  Make it as wide as you want, apply a little glue, slide it in and clamp.

Also the masking tape idea is a winner.  It works very well at preventing splintering of the surface veneer.

[Snipe Hunter]

Depends on the door. I've seen some real thin bottoms like 1/2" and some over 1". I have had to make an insert or two to fill door bottoms.

[BrentDH]

Why not drill a small (1/8" or smaller) hole in from the bottom?  When the drill bit breaks through you will know how thick the bottom edge is and therefore how much you can safely cut off without compromising the structure.  No one will ever see the hole since it is against the floor.

[K. L. McReynolds]

I've made Dutch doors from hollow core doors by simply adding an insert in the open sections of each half. And added inserts to top/bottom when needed.

[Snipe Hunter]

My feeling is ... cut off as much as you need to cut off regardless of how think the bottom stile is. If you don't have return registers in the rooms, you'll want an inch gap between the floor covering and the door to allow the HVAC to work. Or just leave the door open all the time. Making an insert is easy.

[FireWood]

Is it possible that the doors were already trimmed once, upon the original installation?  If so, you may not have as much material in the bottom as you expect.  Not a big problem though.  If you cut the entire frame out to the bottom, it's easy enough to replace.  Just rip a new piece out of some 2X material.  Make it as wide as you want, apply a little glue, slide it in and clamp.

Also the masking tape idea is a winner.  It works very well at preventing splintering of the surface veneer.

Depends on the door. I've seen some real thin bottoms like 1/2" and some over 1". I have had to make an insert or two to fill door bottoms.

This.  It really isn't that bad.

I once converted a hollow core door into a dutch door by cutting it in half and adding inserts back in.