MATCHING INTERIOR MILLWORK

If one lacks professional expertise, installing crown moulding, replacing missing bits of casing or trim around windows, and retrofitting lost baseboards may be an exercise in frustration. Especially when nothing in an old house is square! First learn about the role of trimwork, building up profiles, turning corners with mitered and coped joints, and what tools to use where.

- MARY ELLEN POLSON

THE THIRD DIMENSION From a practical standpoint, adding trim moulding means transitioning surfaces from two dimensions to three, all in the context of rooms where nothing is perfectly square or flush. Consider that repairing or replacing a length of 5 cove moulding set at an angle (sprung) requires working with a special ruler before it’s placed on the wall below the ceiling. Then consider that cornices are traditionally built up from two, three, or more mouldings—complex compositions that can be difficult to replicate today. It all adds up to a process that’s as much about geometry and problem solving as it is about carpentry.

Just finding replacement material is a challenge when the irreplaceable has gone missing. The baseboards in a house built in 1900 were probably cut from true 1 x 6 stock. Today, that 1x6 board actually measures ¾ x 5 ½. A cornice loaded with multiple coves, bevels, and ogee shapes may have been milled from a single piece of lumber. Or it might be composed of multiple mouldings built up to form the profile, meaning you must find all the composite parts at the correct size and scale—and then install them in the correct order!

Finding a match invariably means having a facsimile of the profile on hand as you search. An easy trick to capture the missing profile is to copy it using a contour gauge. (See “Match for a Patch.”) Then check out-of-the-way locations in the house for matching millwork. Look inside closets, on the stairs to the attic, behind radiators, or where a section of wall will be demolished for a new passageway. You may find just enough trim to make your repair.