Yes, I was surprised at what a huge difference it made. Other joints in my
house (the entry way for example) which were mitered REALLY started showing
the difference during the drought this summer, when the north end of the
house settled a measurable 1/4". The coped joints hardly budged.
William Morris, Tailor
OK, I'll have to bite. What is coping, other than using a
coping saw, that is? I have mitered many baseboards, and have
had to make fine adjustments after cutting. Is this a way of
making these "adjustments."
WIlliam Morris wrote:
On 19 Sep 2003, Art Todesco spake unto rec.woodworking:
Coping is cutting the profile of a molding onto the abutting piece. When
the two pieces are fitted together, it is indistinguishable from a mitered
joint. When a mitered joint shrinks with lower humidity, the joint opens
up. When a coped joint shrinks, it is much less obvious.
That's the way it's done but there are tricks to make it easier. If the
piece is short you can cut the straight part on the tablesaw (just set
it for a slight bevel). Then stop the cut and continue the curved parts
with a coping saw. If the piece is long, it helps if you have a RAS.
You can also use a saber saw with a thin blade set for a slight bevel.
(the reason for making the 45 degree cut first is to give you a profile
Assuming a true 90 degree corner, and a foam or otherwise stable
material, a mitered joint in baseboard may look fine. Locally,
painted joints are almost always mitered for speed and since they'll
be caulked. That and baseboards don't show as often as crown joints,
especially outside crown joints (my personal problematic joint, always
takes three or four tries...)
I don't completely buy into the wood movement argument as much, I've
seen bad coped joints from separation as often as bad mitered ones
from separation. And I've seen a whole lot of bad coped joints
because somebody got the trim too short during the coping process.
Coping takes time. Unless a workman is getting paid for the time,
he's not going to take it.
Only one way of doing things? I also taught trim carpentry and I
taught both ways, because their are situations for both. How did
they cope outside corners?
Perhaps if you don't know what you are doing, a mitered joint may
look bad after a while, but I have mitered joints in my parents home
that I did back in 1968 and they still look fine. And thats in a
house with no air conditioning in Brownsville, Texas. Try finding a
place with greater humidity changes than that.
I almost always cope corners, because I do mostly stain grade work,
and to me, coping is as easy if not easier than mitering. It just
takes an extra step. But please don't try to instruct me that there
is only one way to do something,...your way. I have been in this
business too long to believe that.
A good carpenter can make either joint look and last just as long
and as good. I know this from experience. The problem is, there
aren't that many good carpenters anymore, if there ever were that
You might not. The realities of construction might make you
ineligible for some jobs.
Hopefully both coping and mitering.
Keep in mind that a lot depends on the area of the country as well.
Locally, shrinkage is often less of a problem than in northern
climates with a heating season. I'm looking at the original trim
molding in my house right now, all mitered, no cracks, all done in
I'm a Trim carpenter to trade, and as far as I'm concerned all joints (base,
crown, mouldings etc) should be coped, But having said that sometimes if you
pay 50c a foot thats what you will get. Not nowing what he is charging
it's hard to say how he should be doing it. But again if you think the
joints look crappy, then maybe he's just not good at what he's doing.
I did my kids room a couple of years ago and it has a moulding around the
base, a chair rail, then a moulding around the top (not crown ). There were
17 "inside" joints in that one room. I coped them all and got to where I
could to one in about 5 minutes per. It seems harder at first, but whenever
I do miters, I always end up sneaking up on them which takes for ever. I
still can't simply measure a miter cut and cut it dead on. I have to cut it
a hair long, then sneak up on it.
It's always been my understanding that the main advantages to coping over
1. The work for corners that are not exactly at 90 degrees.
2. The joint doesn't spread apart when you nail it to the wall. I still
don't know how you'd miter an inside corner and nail it without it spreading
As far as the expansion/contraction issues to humidity, I'm not
understanding now one would be better than the other. The wood will expand
the same either way. No?
I mastered coping after wasting about 2 feet of molding by practicing. Not sure
why a pro can't do it, unless he is just in a hurry.
After contracting for a lot of renovations this year (windows, siding,
skylights) I am convinced that there are very few craftsmen left, just employees
of companies whose only concern is billing jobs.
I have decided in the future that, where possible, I'll just buy the tools,
practice, and do it myself.
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