How to Figure Angles on Trim Work

Take a small stepping stool or a ladder and put it underneath the ceiling. Do this only if measuring the trim for a ceiling and if the ceiling is high. Have someone hold the ladder if the ladder is placed on a carpet or uneven floor surface. Otherwise use a metal tape measure to measure the ceiling trim from the floor up. Take a tape measure and measure the distance around where the trim will cover. Write down the measurements. Measure each section separately in case the wall or ceiling space has different sized sections where the trim will go. Make sure to measure the wall molding completely from one corner to the other.

Mark the measurement at the corner of the angle on the trim at the top part of the wood where visible. Make sure the pieces of trim are the same size even before cutting the angle. Use your previous measurements to accurately size the pieces of trim. Cut the trim down to size using a hand or electric saw.

Use an angle measuring tool to install the crown molding trim on a cathedral or sloped ceiling. Measure a horizontal section between the wall and the ceiling. Place an angle measuring tool perpendicular to the wall to get an accurate measurement. Make sure the measuring tool is lined up evenly under the area of the ceiling to get the most accurate measurement.

Use an electric meter saw when cutting the angles. Use a zero cut when making a flat cut in the trim. Cut at either a 45 or 70 degree angle, depending on the size marked on the trim and meter saw adjustments.

For an inside cut set the saw to the left. Set the saw to the right for an outside cut. Make sure the cut is even. Cut a second piece of trim and line up the pieces at the angle before mounting to make sure that they fit together identically.