September, 2008

Installing Trouble-Free Doors

Develop a Manual of Practice to train your installation crews

By Gary Katz

In many of my LBM Journal columns, I’ve stressed how new materials and tools have completely changed installation techniques. But when it comes to hanging doors, I’m still using the same six-step process I used 30 years ago and have since taught all of our carpenters. Developing a simple system, especially for complicated tasks, is the best way to increase productivity, eliminate call backs, and bring new hires up to speed quickly.

In fact, when it comes to finish work, each system you perfect, from hanging doors to installing trim, should become one more chapter in your company’s Manual Of Practice: a step-by-step guide that can be updated and improved if materials and techniques do change. A Manual of Practice will ensure that your installation crew always works as a team.

Step One: Level the floor
I can’t count how many carpenters I’ve seen holding a level over their head while setting jambs. Why work so hard? Instead, start at the bottom and shim the floor level.

For interior doors, tack or glue the shim to the floor with a drop of construction adhesive, then set the new jamb on the shim. For exterior doors, always install a level sill pan that’s sloped to drain outside.

Step Two: Correct the rough opening
Don’t wait until a heavy awkward door and jamb are in a sloppy out-ofplumb rough opening. Instead, shim and plumb the rough opening so that its only 1/8 in. wider than the outside dimension of the jamb, from the header to the sill, then set the jamb.

For exterior doors, be sure to caulk the inside edge of the sill to the sill pan, or use low-expansive foam to seal the sill-to-pan joint after fastening the jamb permanently.

Step Three: Shim the top hinge
Use two shims, one on either side at the head of the jamb to temporarily secure the jamb in the rough opening. If necessary, tack the jamb to the trimmers with finish nails, but keep the nails up near the header and down near the floor. Make sure the top of the jamb is flush with the interior finish wall surface (use a spacer block if the drywall isn’t installed).

Then shim the top hinge. (UPDATE: In the last few years, I’ve started placing that shim beneath the top hinge, so when necessary, it’s easier to adjust the door later— more on that below). A heavy door will pull down on the top
hinge and bow the jamb, ruining the hinge and strike gaps. Adjust the bow of the jamb at the top hinge until the hinges gaps at the head of the jamb are equal, about 1/8" above the top hinge and 1/8" at the strike side of the jamb, near the top of the door.

Step Four: Secure the top hinge with long screws. Remove the top hinge screw closest to the door stop (center of the
wall) and replace that screw with one that’s long enough to reach through the jamb and into the trimmer or jack stud.

Never rely on nails alone to secure a heavy door and jamb. In the future, if the door settles for any reason, every member of your crew will know which screw to adjust! Tighten that screw and the top of the door will move away from the strike jamb; loosen that screw and the top of the strike side of the door will drop a little from the head jamb.

Step Five: Check for cross-leg walls and jambs Walls aren’t always framed in a straight line at the floor; sometimes they get banged and bumped out of line, too. That’s called a cross-leg wall. Walls aren’t always perfectly plumb, either, and doors aren’t always perfectly flat. Always fit the jamb to the door. Close the door and make sure it sits flat against the
jamb. Don’t adjust the top of the jamb. Correct all cross-leg wall problems at the bottom of the wall, where the problem originates—otherwise, it’s hard to fit the casing miters at the top of the jamb.

If the door isn’t touching the top of the jamb on the strike side, adjust the bottom of the jamb on the hinge side. If the door isn’t touching the bottom of the jamb on the strike side, move the bottom strike leg to the door.

Step Six: Fasten the jamb Fasten the jamb permanently.
Shim beneath or behind the other two hinges. Shim the strike jamb behind the lock strike and near the floor.

Whether you have five employees or five hundred, a Manual of Practice is a necessity for every construction outfit. A Manual of Practice should also be living document, something that changes with UPDATES whenever necessary. The Internet is the perfect place to publish your Manual of Practice. Make sure your employees are on the same page by holding regular reviews and installation classes.

Pick a different employee to lead the installation class each month. Team work can be fun, and it can make your business more profitable, too! Look to this column for future additions to a Finish Carpentry Manual of Practice.

GARY KATZ, with nearly 40 years experience in the industry, is a contributing editor to Fine Homebuilding magazine, a frequent contributor to the Journal of Light Construction, and produces the Katz Roadshow—Carpentry Clinics at lumberyards all over America. To learn more, visit his web site: www.GaryMKatz.com.