Leon wrote:
I was totally unaware that non solid wood door jams were available. In
Houston I have only seen solid wood jams, I certainly would not want a door
hanging on less especially with a solid core door. I can understand MDF
doors as you can use a longer screw to secure the hinge to the door however
the jam side of the hinge cannot use a long screw unless as you well know
you replace all the screws after installation.

Thanks for the info.

Here's the rub. When the door has been hung and the shims are in, the
shims are roughly 24 inches apart on a three hinge door with shims
under each hinge. However, with MDF jambs, they will easily move and
torque even with shims 24" apart, and the trims properly nailed.

With longer screws that go into the door buck stud you can torque the
jamb if there is the slightest imperfection in your shim fit.

I hang my doors the old fashioned way, using long wedges from each side
at the hinges. Scribe and cut the wedges to fit after the door is in
its proper place, and more nails in the jamb, and a couple of 16 ga 2
1/2 " brads in each shim.

However, I discovered that when I countersink a large finish nail that
doesn't go exactly through the center of the wedge, I can literally
bend the MDF jamb around smaller shims (3" or so) when I am setting the
nails. Now THAT makes a nasty installation.

Robert
Those MDF jambs suck for too many