How to Make a Level Longer
By: Joe Truini
You really can’t get an accurate level reading on an area that is larger than your level without a little modification. Effectively extend the accuracy of the level by putting it on top of a perfectly straight 2×4.
If you purchase a new 2X4 for this purpose be sure to use it within a day or so since it may warp as it dries out. On a vertical surface you may want to tape the level to the straight board to simplify the process.