scribing facia to ceiling
scribing is simply cutting a piece of material to fit against an irregular surface. it is an important technique in all carpentry phases (including rough work e.g. concrete forms abutting stone) but is especially common in finish work. there are many different ways to scribe and many situations where scribing is necessary.

some hand tools i use while scribe cutting
this situation involves fitting two pieces of facia on the top of the cabinet run to an irregular ceiling. the facia is intended to be 2 ¼” tall when finished, but I added an extra ½” to the board knowing that I would end up removing some material to fit the ceiling. So, as long as I do not have any gaps more than ½” in the initial fit, this should be now problem.

initial gap at right of facia

left of facia touching ceiling (low point)
the low point on this ceiling was at the outside corner of the cabinet run. with the facia level, the gap at right was ½”. to fit the piece tightly against the ceiling with no gap, I have to follow the contour of the ceiling and transfer this shape to the facia. to do this, I use a scribe tool.

ruler used to set scribe tool