How can I use a rotary laser level with a building in the way?

[Scott Winners]

If you can get it done fairly quickly you might be able to use mirrors to " go around." I have only fooled with lasers on tables in a lab, but if you can use mirrors to go around the obstacle clockwise, make a mark; leave the laser fixed, go around the obstacle counterclockwise with mirrors and hit the same mark your done. Bring the laser around the obstacle, line it up to your marks and move on to the next step. Your mirrors need to be lab grade flat and lab grade vertical.

NB: there are often unforeseen problems moving out of the lab into the field. A decent lawyer should be able to explain a water level to a jury in under three minutes. Archaeology field school was many many moons ago for me, but Walter is right about using grade poles (stadia rods), shortest number is the correct number.

[Jerome Stanek]

If you can get it done fairly quickly you might be able to use mirrors to " go around." I have only fooled with lasers on tables in a lab, but if you can use mirrors to go around the obstacle clockwise, make a mark; leave the laser fixed, go around the obstacle counterclockwise with mirrors and hit the same mark your done. Bring the laser around the obstacle, line it up to your marks and move on to the next step. Your mirrors need to be lab grade flat and lab grade vertical.

NB: there are often unforeseen problems moving out of the lab into the field. A decent lawyer should be able to explain a water level to a jury in under three minutes. Archaeology field school was many many moons ago for me, but Walter is right about using grade poles (stadia rods), shortest number is the correct number.

Mirrors can be off by feet if they are not aligned correctly and to align them could take hours.