cj wrote:
i have a wall that is about hip high that forms a 90 degree enclosing a
set of steps going down to the basement. i would like to widen( or cap )
the top with some wider lumber so that it may be used for placing
knick-knacks, pictures etc. but it seems to me that the length of each
piece (forms a 90 )needs to be longer than the narrower mitered pieces
that i will be attaching to. am i right and is there a formula to
determine what the length of the new wider pieces of lumber that will be
attached?

Finished overall length is distance to outside of wall plus overhang.
Start by making the miter joints fit w/ material w/ length to spare then
cut square ends to length.

If use very wide solid material, be _very_ sure it is _completely_ dry
or the miter will open up as it dries and shrinks. If you want a really
wide cap, you might consider using cabinet-grade ply for the main pieces
and face it w/ matching hardwood.

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