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Norm's Notebook: Levels

Master carpenter Norm Abram shares his techniques for choosing and using levels

level
Illustration by Harry Bates
1 ×

 

Test for Accuracy
The field-test for level accuracy is so quick that I perform it almost every time I use the tool.

Step 1. Place a level on a flat surface and read the bubble position in relation to the lines on the vial.

Step 2. Keep the level horizontal, pivot it 180 degrees, and place it back in the same spot. If the bubble returns to the same position in the vial lines, then it's accurate. Repeat the test for each vial in the level. (For the vials that measure plumb, like the one I'm looking at in the picture, flip the level onto its opposite edge.) If one vial is off but the rest are consistent, you can mark the bad one so you'll know to ignore it.

Test for Accuracy
The field-test for level accuracy is so quick that I perform it almost every time I use the tool.

Step 1. Place a level on a flat surface and read the bubble position in relation to the lines on the vial.

Step 2. Keep the level horizontal, pivot it 180 degrees, and place it back in the same spot. If the bubble returns to the same position in the vial lines, then it's accurate. Repeat the test for each vial in the level. (For the vials that measure plumb, like the one I'm looking at in the picture, flip the level onto its opposite edge.) If one vial is off but the rest are consistent, you can mark the bad one so you'll know to ignore it.

2 ×

Proper Posting

 

Proper Posting

level
Illustration by Harry Bates
Using a square to level around the corner
To check a vertical post for plumb, as Norm is doing in Image 1, put the level on two adjacent faces, and look at the bubble straight on, not from an angle. The same holds true for flat surfaces, such as a countertop. Place the level so it's running from side to side, then turn it 90 degrees and check again back to front. If there's no discrepancy, the surface is level.

Turning a Corner
A level is fine for drawing level lines, but if that line has to turn an outside corner, a combination square is the easiest, most accurate way to mark the turn. First, draw a level line on one wall right to the corner. Then place the square's rule on the adjacent wall (as shown in Image 2). Align it with the line you just drew, and make a mark on the adjacent wall. Now line up the level with this mark and continue drawing your level line (as shown in Image 3).

Perfect Pitch
If I'm doing work that requires a constant pitch, such as hanging a gutter, I'll tape a block of wood to one end of the level to give it the desired pitch. For example, if I need a slope of 1/8 inch for every foot, I'll tape a ½-inch block to the end of a 4-foot level (4 x 1/8 = ½). That way, when the bubble indicates level, the gutter has the proper slope.

Tip: Whether I'm checking a vertical piece for plumb or a horizontal piece for level, I always use the longest level that I can because it gives me the most accurate results.
 
 

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