Setting out stud walls and track with a laser level

Why the laser changes the method

With a plumb bob you carry one point at a time, and every transfer piles on its own error. With a laser, the vertical plane gives floor and ceiling at the same time: plumb stops being a run of checks and becomes a property of the setting out.

It is also what lets one person work a length of wall that used to take two.

Step 1 — Where do you put the instrument?

On the line of the wall to come, offset by a few tens of centimetres so as not to be in the way, at a height that keeps the beam off eye level. An instrument with 360° planes needs no aiming: it lights every direction.

Step 2 — Mark the axis on the floor

Line the vertical plane up on the two starting points of the wall, usually a mark on each existing wall, then mark the floor about every metre. The chalk line will join those marks afterwards. It is that axis, not the wall beside it, that the whole partition is set from.

If the two existing walls are not parallel, this is the moment to find out, not when you fit the last board.

Step 3 — Carry it to the ceiling

Without touching the instrument, look up: the same vertical plane marks the ceiling exactly plumb above the line on the floor. Mark at the same intervals and snap the line as you did below. The two lines then sit above each other by construction, with no transfer and no plumb bob.

This is where most is gained: no transfer, no plumb bob, no piling up of error. If the ceiling is high, the telescopic pole holds the instrument at the right height.

Step 4 — Fix the track

Floor track on the floor line, head track on the ceiling line. Fix the ends first, check that the two runs sit one above the other along the whole length, then fix the points between. A track set by eye is paid for later, in studs that refuse to come plumb.

Step 5 — Check the studs

A stud sitting in two plumb runs of track is plumb by construction. Checking with the laser is mostly about finding a twisted or badly seated stud: run the vertical line down the face of the studs and the odd one out shows at once.

There is no need to check every stud with a level: if the setting out is right, they are right.

Step 6 — The heights

The horizontal plane then serves everything that sits at a constant height: back boxes, noggins for wall units, door linings. An instrument with four planes such as our 16-line lets you keep the horizontal lit while you work off the vertical.

What if the floor is out of level?

The wall follows the floor, but the heights must stay constant against the horizontal, not against the floor. Take every height from the laser's horizontal plane: it is the only reliable reference in a room that is not flat. The floor slopes; the heights do not.

For the method on tiling, see this guide; for choosing the instrument, this one.

See the laser levels for stud walls