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Split-jamb doors......

George_Abramshe's picture

The buider I'm doing trim for is installing split-jamb doors and will not be talked out of it. Anybody have any tricks or comments to make my life easier and to assure a well hung and operating split-jamb door? I'd just as soon do without them but shimming and hanging is going to be a pain with no access behind casing. I was thinking of removing the casing on the hinge side ,shimming, then reapply the casing. Either way it is more work for me. Thanks.

(post #158155, reply #1 of 9)

George, I always get the door square in the R.O. & tack it off through the hinge side casing then shim at all three hinges and at least right behind the strike then put a nail thru each set of shims hinge side then all you have to do is plug in the split side of your jamb & nail thru the casing .

(post #158155, reply #2 of 9)

George, "split" the jamb apart.

Center the "door half" in the opening. (many like to hug the frame with the hinge side, but centering allows you more wiggle room to align the door in the frame, see last step.)

Plumb the hinge side and check your door/jamb reveal at the top. If the hinge side is too low for a proper reveal at the top either shim the hinge jamb or trim the striker jamb. Nail the casing off maintaining a uniform reveal.

Shim each jamb, everyone here has their own method but I don't mind starting a bunch of crap so I'll tell you what I think. The standard practice is to shim three on each side, none on the top. The most important one is the lower hinge shim, that is where all the stress is. If you are hanging a heavy door you may also want to sink a long screw into the top hinge to take some of the weight. I also pay attention to what is used for flooring and wouldn't think twice about adding shims at the bottom of the jambs if a threshold or wood flooring is being used. To each their own, and I am sure you have this part of the process down, but I recomend that you shoot a nail into the shims to keep them there during the next step. Also it wouldn't be a bad idea to mark where the shims are for the second step from here.

Now insert the other half of the door frame. You want to tack the top corners first, after you align them with the other half. Then tack the bottoms, after alligning them. Get the jambs straight here or you will look like an idiot. Finish nailing off the casing.

Now you need to nail thru both halves of the jambs, into every shim. First step here is to close the door and see how it meets the stop, this is where the wiggle room comes into play. The door or house would have to very messed up for you to be unable to get this reveal very uniform, so use the play you have to get this right. To some extent you can squeeze the jambs togeather to improve the casing miters, so remember that you have two halves to play with and a lot of things to do.

Good luck guy, I bet you will be a pro after a house of these things.

(post #158155, reply #3 of 9)

Thanks , I've hung hundreds of doors but have only dealt with these once before and it was many moons ago. From what I understand it is a solid core ,six panel pine door.

(post #158155, reply #4 of 9)

A tip that I like when installing split jambs is to grab a handful of ships and cut them of on your chopsaw to 4" or so long.

This will leave you plenty of sizes of shims to place horizontally as if you were installing a flat jamb door. Keep them in a small box and it is easy to spot the two that will work for a given gap.

Split jambs suck because you cant fine tune the stop, but properly installed make for a serviceable door.

I would never not shim them ala that Katz guy who writes for fhb. It only takes a friggin minute.


(post #158155, reply #5 of 9)

I like most of Gary K's article , but I stil shim split-jamb doors. Solid-core? Definately! I cut a bunch of shims in half like Tommy mentioned , and I place them running up and down the jacks so I don't have to trim them . I also keep plenty of 3 x 3 squares of 1/4 inch ply handy when hanging any doors-if the hinge side is framed plumb (occasionally) I can shoot one of the squares behind each hinge and am ready to hang the door in a few seconds.I do not like split jamb doors and I think that they require work to make them feel solid, but I will gladly hang them instead of staying home.

(post #158155, reply #6 of 9)

As for the shim deal, I make up a bunch at a time. Rip them to about 2" and chop the length in thirds, fill a box or a 5gal bucket. Why? I buy the shims because builders either forget, buy junk, or don't buy enough. The shims being all the same size are very easy to handle and install, provide three sizes, and I have less waste.

I install splits in a production manner. Remove the shipping debris and move to their location and split the doors.

Hang all the door sides.

Shim and install the backs.

And Tom, why do you think you can't fine tune the stops? The only prob I have is when a door is warped beyond belief or the frame is porked.

(post #158155, reply #7 of 9)

We hang split jambs all the time, and, do pretty much like everybody else has said. We cut our shims to 3" so there's definitly no trimming.

All the split jambs we do have the stop molded as part of the jamb, so we have to tweak the whole assembly. With solid core doors, we put a long screw through the bottom hinge as well as the top. Cheap insurance, and another good tweaking point.

(post #158155, reply #8 of 9)

The buider I'm doing trim for is installing split-jamb doors and will not be talked out of it. Anybody have any tricks or comments to make my life easier and to assure a well hung and operating split-jamb door? I'd just as soon do without them but shimming and hanging is going to be a pain with no access behind casing. I was thinking of removing the casing on the hinge side ,shimming, then reapply the casing. Either way it is more work for me. Thanks.

split jamb doors production style (post #158155, reply #9 of 9)

As a carpenter who started out hanging doors with a chisel, a "Yankee", and a jack plane, I would like to offer an alternative to the methods I have seen in this post.

Like George, my first experience with split jambs was a real pain, because I had never seen one before. I actually did remove the casing to try and shim the doors after they were hung. After having to replace the badly damaged casing (those staples just do not come out easily), I wrote off ever using split jambs again, believing them to be a malicious invention of some carpenter hater.

Now that I am for the present employed as a trim carpenter on new housing here in Florida, I have been required by reality to adjust my opinion and method of installation of these doors. Split jambs are used by nearly every builder I have met in Florida. Only the entrance doors are solid jambs. Since the trim carpentry package, which includes baseboard, interior doors, and locksets, pays about 30 cents per square foot heated space plus garage, one cannot lavish too much time on anything if one is to survive, let alone make a profit.

First, all of the doors are distributed to their respective locations throughout the house while still closed up, because after being stripped, they are difficult to move without breaking the joints in the casing and jamb. The split jamb spacers are broken off, double head nails pulled, and reveal spacers scraped off (peel and stick type). Each jamb is then separated, being careful to locate the non-hinge part as close to its final location as possible

We use a 6" piece of 2x2 ripped to 1 1/4" x 1 1/4" as a starter block placed in the center of the door opening. An 18 gauge pinner with 2" pins is the primary fastening tool. The hinge half is placed in the opening, with the door slab resting on the 1 1/4" block. This is 99% effective in eliminating going back at the end of the job to cut door bottoms. Resting the jamb ends on the floor almost guarantees this callback. The floating jamb ends have never been a callback issue.

We nail the door off through the casing, starting at the top hinge corner, working down the hinge side, across the top, and down the strike side. No, we do not use a level to do this. The goal is to keep the reveal around the door even. We then check the jamb for cross-legged framing, where the sides may not align vertically, whether or not they are plumb. If the door meets the stop continuously top to bottom, then we move on to the next step. If not, then we adjust the bottoms of both sides of the jamb by pushing in or out until the alignment is correct, and then drive a 15 gauge nail through the jambs, being careful to avoid the groove for the other half of the jamb. Yes, this may mean that the width of the jamb will vary from top to bottom, but this has never been a callback issue on the doors we have installed.

The non-hinge side is then installed using 18 gauge pins through the casing .At the bottoms of the jamb, we adjust the two halves so that they maintain a 90 degree angle to the door slab. After checking door swing and reveal, we then drive a 15 gauge nail above and below each hinge at about a 20 degree slant to prevent the door from moving at the hinges. That is right, we do not use shims. We have never had a callback on this either. This method has worked well for all hollow core door types, both masonite molded and flush. Some solid core doors may require a shim, but I have yet to meet a builder who uses solid core interior doors on production housing.

If you had told me 30 years ago that I would ever hang doors like this, my Chicago North-Shore quality experience approach would have said you were crazy, but reality is a funny thing. As I said at the beginning, hanging a door used to mean, milling the jamb from clear stock, rabbetting the heads, screwing the jamb together, mortising the door and jamb with a sharp chisel, drilling the door for hardware, screwing the jamb plumb and level to the opening, shimming at 5 points hinge side, 3 points jamb side, nailing casing to the jamb and the stud to keep the jamb from moving, installing the stop to allow clearance on the hinge side, and a perfect mate on the strike side, covering all the screw holes. Then bevel the edge of the door with a jack plane. Then drill all the hinge and strike screw holes and install the hinges and lockset, driving the screws with a "Yankee" ratchet screwdriver. If I have left out anything here, it is probably because these days I don't often have the opportunity to hang a door this way.

When I first aspired to become a carpenter, the question a prospective employer would ask was, "Can you hang a door?" If the answer was yes, you were given the chance to prove that you were not lying. I don't think this question would mean as much today.