Crown Molding - Quick Guide to Spring Angles

When it comes to cutting crown molding on a sliding compound miter saw, spring angle plays a key part in getting it right. If you don't understand "spring", you need to read this.

Making crown cuts on a sliding compound miter saw is tricky enough as it is, but when spring angle comes into the equation, it's yet another thing that can lead to mistakes and a waste of good wood. You need to know what spring angle your molding has, but first of all you need to know how to choose the right type for your room.

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If you are going to the trouble of cutting your own crown molding, the least you can do is choose the appropriate type for the height of your ceiling, and that is where spring type comes into play. The industry makes three common types -- 38 degrees, 45 degrees and 52 degrees. Basically, the lower the ceiling, the lower the angle to choose. This is because the spring is the angle at which the molding sits away from the wall.

The best angle at which to view molding is face-on. In a room with a lower ceiling, the average person's eye is closer to the molding, so to get a face-on view, the molding has to be angled more steeply, which means that the lower 38 degree spring angle is best. Conversely, for a room with a higher than average ceiling, the crown molding needs to be angled more shallowly because the average viewer will be lower in relation to it. The molding basically needs to point down towards the viewer more, so the higher 52 degree spring is best. For an average ceiling, the normal 45 degree spring will be the optimal choice.

Now, if you have already purchased your molding, and you didn't pay any attention to what spring factor it was, you are going to have a hard time cutting it on your sliding compound miter saw, especially if you intend to cut it flat using a bevel setting on a sliding compound saw. So, it's important to find out what spring your molding has before you start.

A quick way to determine the spring angle is to take a piece of waste wood and make a clean 45 degree miter cut. Now take a piece of the crown molding and press the angled section at the back of the bottom part (the part with most decoration) against the fence of your compound sliding miter saw. The fence is acting as the wall of your room and you are looking at the molding from above, as if it were sticking out from the wall.

Now, drop the 45 degree scrap wood into the gap behind the molding. If it won't fit, you have 38 degree molding; if there's a gap, you have 52 degree molding; and if it fits perfectly, you have 45 degree molding. It's as simple as that.

Crown Molding - Quick Guide to Spring Angles