Holy crap it's a pain to do with a miter saw...

I'm curious, though, what you guys do where there's carpet on one side of the door and hardwood on the other. Do you just cut half of it stopping after the piece of wood that the door stops against (whatever the name of it is)?

Yes, and use a sharp chisel to make the downward stop cut.

Its called the door jamb. In my house what I do is tear up the carpet on the other side and install hardwood. Thats because its what my wife makes me do. Now you can simply cut the door jamb all the way. Much easier isnt it?

I would advise you to use a regular old fashioned Stanley 30in hand saw. It will zip right through a door casing in just a few strokes. I assume when you say "miter saw", you are referreing to a short, stiff backed hand saw. Yeah, that would be a pain.

Scott, I know it's called a door jamb. My question refered to the extra piece of wood which stops the door from swinging further. Or is that technically called the jamb and the rest is the casing? I am assuming that this piece gets trimmed and that's where the wood stops and the carpet begins (under the door). That is, unless you do what your wife tells you unquestioningly all the time. Heck, it'd be much easier to simply pay someone else to do the whole house...

Chuck, good call. Yeah, the stiff-backed saw. I figured that the shorter saw would do better in the tight spot.

The small rectangular piece of wood attached to the jamb is called a door stop. Those are normally undercut to run the flooring underneath. Pull back the carpet to allow to undercut the stop and the jamb (the wide 4.5" flat wood piece the hinges are attached to) Casing are the trim pieces which cover the gap between the sheetrock (or plaster) walls and the sides of the jambs. These should always be undercut for wood floors. A back saw will work but you need a quality one, like a Disston.

http://cgi.ebay.com/DISSTON-BACKSAW-MIT ... dZViewItem

Here's a trick I used with my ordinary Dremel, with a "roto-cutting bit" and the "flexible arm" attachment.

The handpiece of the flex arm is only about .5" diameter, so I lay it horizontal on the floor and use various scrap pieces of plywood/boards/small metal plates to shim it so that the top of the roto-tool is at the correct height for undercutting door casings, etc. It goes through soft wood like butter, so the hardest part is holding on FIRMLY so it doesn't run away from you.

Then, just slide the roto-bit along the floor, held down tightly against the shim materials. Cuts through door jambs, etc easily and makes a smooth cut, as if done by a fixtured router.

Good luck.

I have a Bosch fine cut saw. It's an amazing tool.
http://www.amazon.com/Bosch-1640VSK-Fin ... B0000223FQ

That Bosch is my favorite too for door jambs. This is where i bought my last one http://bosch.cpotools.com/saws/power_ha ... vs-46.html

dont any of you use a crain undercut saw?

I used a Roberts Jamby for 6 years and broke down and bought the Crain this spring.

I use the crain, but that bosch looks pretty trick. A lot less dust would be good on some jobs. Bought my crain before they sold them with dust ports.

I got two Crain undercuts.... model 812 and 820. But for door jambs I like using the Bosch Finecut. I use the Crain saws on hearths, pocket doors, baseboards or inside corners and to reach underneath cabinet toe-kicks. If one of you has the older version 820 you can convert it over with the dust port feature, Crain sells a kit to do that.

I've been using my 4" grinder with the serated diamond blade in it. Unconventional, but after I used it to undercut my fireplace I tried it on the doorjams and it works great.

Dangerous as heck b/c no shield but the 5/8 inch arbor 4 inch mini saw blade will fit, albeit slightly loose, on a metric size Rotozip arbor. Crank it up and saw away. Be very careful of kickback b/c it will. Rotozip makes an undercut attachement but it only cuts 3/4 inch in. I had to go about 1-1 1/2 inch under the jamb to make my cuts. Mine aren't pretty and I'll probably have to touch them up afterwards but it was a cheap alternative.

I have seen a modified circular saw that basically you hold sideways with no guard on it so it rests pretty much sideways, flat on the floor. Just crank it up and cut in.

Also, and probably a better setup, is to put the saw blade on an angle grinder (size appropriately the mini saw blade to the arbor) and you will have to remove the guard with the same risk of kick back the Rotozip has. Benefit would be that you could lay it flat on the ground and not have the arbor hit the floor like with a Rotozip. (A traditional undercut saw looks just like this anyway, I don't know why someone just doesn't make a smaller blade and a sliding mechanism to use an angle grinder for this purpose. Probably b/c they make the undercut saw too...mo money)

I think maybe the slotted diamond blade may be safer and usable as well b/c the wood cutting blade from Rotozip looks just like a diamond imbedded slotted masonry blade. I don't know for sure but it doesn't look like a torture device like my mini saw blade.

I did the undercut manual saw thing too and whew, that will tire you out. If they made the stupid hand saw more rigid I would have kept doing that but it flexed, bent and flopped all over. What POS.