Return to the Woodworking Forum | Post a Follow-Up

Pre Hung Door Installation

Posted by snookums2 (My Page) on
Mon, Nov 7, 11 at 17:15

Another woodworking issue. Two prehung doors have gone in. On the one door, the jam looks beautiful and fits flush to the floor. I was thrilled to see it so neatly done yesterday. Today, the next door went in. Only one corner is resting on the hardwood. There's a 1/8" gap on the front portion of one jam. I guess we can't really expect perfection. But the right jam is sitting high all around at 3/16". It looks sloppy and poorly planned, imo. Is that acceptable? What's the tolerance for these things?

I know they'll blame the floor but would think it would have been scribed or each side measured separately to ensure a good fit. While not a highly visible area, I don't like it at all and don't want it happening everywhere. Can that side jam be removed and replaced for a better fit? I'm expecting to hear 'caulk' which would look tacky and conspicuous, imo. There are also chips at the bottom on that side that I don't see how will get covered. I'd think fill would chip off again.

How much do you undercut your doors and how much is needed for rug clearance? There seems to be some debate over this when I researched it. I'd asked for 1/2" as most carpenters were quoting. It does seem a little tight over a rug. This second door came out 3/4" but maybe because of the elevated jam. Is it hard to achieve accurate or consistent undercuts? My understanding is 3/4" is the max standard for fire safety.

Expecting too much?

Follow-Up Postings:

RE: Pre Hung Door Installation

Sounds like bad installation on the second door.

The consistency part of undercutting depends on the tools used to install. A jamb saw makes consistent cuts. A power jamb saw is also several hundred dollars and not used by many installers for that reason. Hand saws are most often used. The wrong type of hand saw can leave/make chips.

Clearance for carpet is a local codes issue or just plain installer/home owner preference. The clearance is more for the door itself than the frame. That is why most prehung doors are shorter than the frames.

It is not unusual for the two sides of a prehung frame to be different after installation. Floors, off plumb rough openings, and out of plane walls all can contribute to unequal spacings. And there is always just incorrect installation.

Are you expecting too much? Not if you are paying for perfect installation. Was that specified before selecting the folks doing the installation?

RE: Pre Hung Door Installation

If it's sitting on hardwood, you have to scribe the jambs and casings to accommodate any slope/variance in the floor. On carpet, not so much ;-)

RE: Pre Hung Door Installation

I just asked to have a door hung. I wouldn't know how to approach it other than that. For all the time they spend doing things and what we end up paying by the hour, I guess I kind of expect a very good or somewhat perfect job. I thought he was meticulous but it's turning out apparently not.

Casey, I wish you could work on my home. Yes, I would think scribing would be necessary on hardwood to get an accurate fit.

I mentioned it to him and he stated a few reasons. He said he'd try to adjust it but I have a feeling he will forget when he gets back to that project. Or bang up the floor trying to fix it. They say pick your battles but it's hard to know which ones. You don't know what else is coming until you're there.

RE: Pre Hung Door Installation

This apparently is a problem door they will work on more. I brought up that I want the jams/casings flush to the floor and the others that went in look good.

Door Cuts

Two of these doors need to be cut down. When I was looking at double doors, the salesman told me the cuts get a 3 degree bevel so they close nicely and don't chip at the edges.

This is a 30" door that needs a bit cut off both sides. I don't think the bevel is necessary here since there's a gap on each side of the door. Not two doors closing into each other. Right?

Doesn't it take a special table saw or equipment to set to the bevel? They have a portable table saw. The large one is miles away. I think in the past, the doors were just cut by hand.

We can't do the best most beautiful way, I guess, just don't want any problems.

RE: Pre Hung Door Installation

Several ways to cut bevels---a table saw being the least desirable.

Before power tools, a hand plane was used. Still ma really good way as mistakes take much longer to make. But, the skill factor is much higher.

Power hand planes are probably the most convenient tool now. Those will chip out at the ends of the doors, so experience/skill are necessary.

The 3 degree bevel is so the door clears the jamb as it opens/closes when the clearance us less than about an eighth of an inch. If there is 1/4" or more clearance on the latch side, no bevel is necessary.

RE: Pre Hung Door Installation

okay, so we should be clear. Looks like they do about 1/8" and it is free.

Those bevels do look nice. Big table saw back at the shop has a setting for degree as I understood it. I'm surprised that isn't the best way. Thought that was how the mills did it.


RE: Pre Hung Door Installation

Big difference between a manufacturers factory and a jobsite operation.

Trying to bevel even a hollow core door on most woodshop/jobsite table saws is very unsafe without several out/sidefeed supports and a minimum of two people.

In fact, I can bevel a door with a plane---hand or power---faster than I could set up a safe table saw operation.

RE: Pre Hung Door Installation

I had no idea that was dangerous. Guy at the HD said they are not permitted to take small edge amounts off of something for that reason.

RE: Pre Hung Door Installation

All due respect for folks who work in home improvement stores---most are not even minimally competent.

That is one reason they are not allowed to do many tasks. And I never ask for advice, unless I am familiar with the person.

RE: Pre Hung Door Installation

That is so true. I am amazed at their lack of training and how little they take interest in their jobs to educate themselves. Very frustrating to go in, ask something, and find you know more about it than they do or they're just making stuff up. That's why I try do my research prior to shopping.

RE: Pre Hung Door Installation

The doors are hung and I notice 3 of them are not square in their jams. The upper left is higher so the door drops down on the other side. On two the top of door latch side isn't laying flush with the jam. And there's a triangle gap of light where it gets wider. The doors should block out noise and these gaps would seem to allow it to pass through like on the public powder room which is right off the living room.

Is there any way to adjust this now that they're hung and the nails are sunk? Is there an inherent reason my house might not hang square doors or is that installation? Casing is supposed to go up tomorrow.

I really wish I could do all this stuff myself and hate having to bring these things up. I don't feel it's too picky but they probably will. I expect to hear that there's something wrong with my house so it can't be done. We are paying an awful lot for it all.

RE: Pre Hung Door Installation

Along the top of the door, the gap is 1/8" on the left hinge side and expands to 1/4" on the right.

Hinge side it is 1/16" at the top reducing down to nothing at the bottom.

Bottom threshold goes from nothing on the left hinge side to 1/4" on the right.

Latch side barely makes 1/8" at the top and expands to 1/4" at the floor.

RE: Pre Hung Door Installation

So is this picky, normal and I should let these things go? I'm under the impression the gap should be consistent around the door so that the door is square to the frame. And that it's needed to avoid rubbing. The studs are not in the way. There is a sufficient gape from the frame to the studs for shimming. These were those narrow metal framed doors previously so it's hard to compare the fit.

RE: Pre Hung Door Installation

How long should it take to install a pre hung? Or a slab door?

I'm reading guys can do 10, 20, even 40 doors a day. They don't do this every day but are in construction doing a variety of tasks so not DIY people. They both have carpentry skills. I've got 3 pre hungs and 2 slabs that are yet to be completed is why I'm asking.

RE: Pre Hung Door Installation

A real slab takes more time sine it must have hinge mortises cut and be bored for the latch.

If you do a lot of doors you a router to cut the hinge mortises with a jig to limit the cut out area.
It takes longer to measure & position the jig tan to cut the mortise.

The same for bring for latches.
A jig is clamped to the door and locates and guides the hole saws.

It can go very quickly.

If you only have a door or two and no plans to do any more then the work is often done by hand.
It takes about 10-20 minutes for each hinge mortise with a couple hand chisels.

For a two hinge door you need about half an hour.

Laying out and boring for the latch is about 15-20 minutes more. Remember to switch aides when boring for the knob hole when the pilot bit of the hole saw breaks through.
Hole saw exit edges are rarely clean.

Any adjustment to the size of the slab door are going to add time.
In many cases the age of the house determines if stock doors will fit without adjustment. 'Standard' door sizes have wandered around (just a little, but it matters) as jamb designs have changed and settling can also affect jamb size and shape let alone 'adjustments' made at the time the house was built or latter).

Most of the time slab door seems to rarely 'drop in' on a house 40-50-60 years old.

Beveling the strike edge should only take a few minutes, but a hand power plane really speeds it up.
It also allows you to wreck the door very quickly.
You can wreck it slower with a hand plane.

RE: Pre Hung Door Installation

So it seems it takes maybe it takes a couple hours to do a slab. An hour to prepare for hanging. Maybe another hour to hang it on the frame and shim to try to square the door in the frame and to put the knob on?

A prehung then hangs faster? Just the need to shim the frame in and square the door inside the frame. Put the knobs on.

I asked a guy at Lowes and he said he "put a prehung on in about 15-20 minutes, you say 2 guys, haha?" I was reading the other day a guy saying he was hanging only 10-12 a day trying to better his production to 20-40 like others. They are in construction but do a variety of tasks, not just doors.

These five doors (3 prehung, 2 slabs) were started I don't know, over a week ago, probably more. They stop and start work on them rather than just finish so it's hard to say how long it's actually taking other than it being involved.

The two existing frames are not plumb so squaring the door might not be possible, I guess. As I recall it took quite some time for the two of them to put the frame in on the prehungs, as in hours. They still aren't done.

Does it take two guys to hang a door? They seem to do every-thing together rather than independently.

We are charged by the hour.

RE: Pre Hung Door Installation

"Maybe another hour to hang it on the frame and shim to try to square the door in the frame.."
If you are putting a slab in an existing opening shimming is not usually very productive. The only thing you can shim are the hinges to move the whole door slightly.
you adjust the door size and shape to fit the opening.

"As I recall it took quite some time for the two of them to put the frame in on the prehungs, as in hours. They still aren't done."

if the openings are sized correctly and reasonably square (framing is often not perfect, that is why do jams are plumber and squared with shims) it should not take all that long for an experienced worker.

Installers that do nothing but doors are going to be faster than finish carpenters that instal doors as part of a larger job.

Two workers makes a lot of the job faster, but a single worker can do the job (it just takes longer).

Are you paying by the hour or by the task?

 o Post a Follow-Up

Please Note: Only registered members are able to post messages to this forum.

    If you are a member, please log in.

    If you aren't yet a member, join now!

Return to the Woodworking Forum

Information about Posting

  • You must be logged in to post a message. Once you are logged in, a posting window will appear at the bottom of the messages. If you are not a member, please register for an account.
  • Please review our Rules of Play before posting.
  • Posting is a two-step process. Once you have composed your message, you will be taken to the preview page. You will then have a chance to review your post, make changes and upload photos.
  • After posting your message, you may need to refresh the forum page in order to see it.
  • Before posting copyrighted material, please read about Copyright and Fair Use.
  • We have a strict no-advertising policy!
  • If you would like to practice posting or uploading photos, please visit our Test forum.
  • If you need assistance, please Contact Us and we will be happy to help.

Learn more about in-text links on this page here