Accurate measuring, marking and levelling are essential in any DIY job, so invest in a quality tape measure and follow these simple tips.
- The rule: measure twice and cut once. It's better to rub out a mark and put in a new one than to waste a length of wood.
- Always read off and mark measurements with your eye vertically above the tape if it is horizontal, or level with the tape if it is vertical. If you do not do this, a visual error called parallax occurs and the mark you make will be inaccurate. Always measure and mark twice as a double check to help eliminate this error.
- Set a wooden or folding rule on edge when you're using it to mark measurements on a workpiece. Then the graduations on the face can be transferred straight onto the workpiece. If you lay the rule flat instead, the absence of any edge markings makes it difficult to mark the dimensions accurately.
- To check a horizontal, rest a level on the surface being checked and view the vial in the long edge from directly above or beside the level. Adjust the surface until the bubble is precisely centred between the marks on the vial. To check a vertical, hold the level against the surface and view the vial at the end with the eye at the same level. Adjust the position of the surface until the bubble is centred in the vial.
- To check the accuracy of your level, place it on a relatively level surface. Use a shim to wedge up the low end until you get a level reading. Make sure to stand perpendicular to the vial when looking at it. Once you get a level reading, turn the level around 180°. If the vial still shows level, you're getting accurate readings.
- Place your level against a door frame to check that your level's vial gives you a plumb reading. Tape paper shims to the jamb until it's plumb, then flip the level upside down and check for plumb again.
- Levels tend to slip when you're trying to mark a line on a wall. Slip several rubber bands (or one fat one) over each end to make an anti-skid level.
