Laser Layout for Out-of-Whack Rooms

Here's a good description of how to use a laser level to set benchmark plumb and level layout lines on a room that's not built square, plumb, level, or true. July 12, 2008

Does anyone have a good procedure for squaring a room in remodeling? We have a horrible room with walls that are almost organically out of whack. Not only are they out of square, they are out of plumb and have convex surfaces. We run into this often and generally build our kitchens to the smallest dimensions with extended sides for scribing.

We have always lasered a benchmark around the room to determine ceiling and floor level. We recently started to add floor layout lines (width and length axis lines) to measure and reference from. We generally put at least 2 lines. In a larger room we might put 4 lines. Sometimes our axis lines reference major elements in the room, such as the center of a door or the center of a hearth. Most times what we need are axis lines parallel to the major wall and perpendicular to the short wall. Factoring in the out of square and plumb both walls. We generally do this by trial and error.

I am thinking that a laser meter with a right angle function might make this go faster. Anyone have a good quick system to square up a room like this with or without a laser meter?

Forum Responses
(Cabinet and Millwork Installation Forum)
From contributor D:
I use a Topcon drywall laser. They give you a straight line that you can dial onto a mark on the floor and a line 90 degrees to that line. You use reference lines on the floor laid out with the laser and measure all your points in the room off these reference lines. Typically what I would do is start in a corner, measure 2' off each wall in the corner so you have a 2' offset each way, then put down a 2' mark at the far end of the wall, set up the laser over the mark that's 2' offset each wall and dial the beam into the 2' mark off the far wall. The laser will give you a 90 down the other wall. You use this square reference to take your field dimensions.

From contributor S:
A lot depends on what you are looking for and how much you want to do. I build retail in the malls mainly. One of the first things that we do is control lines and bench marks. Never had a space that was what it said it was supposed to be on paper yet!

For a one room show I would use a spinning laser and put a bench mark around the room checking for highs and lows. I would also check for highs and lows anywhere else that I knew was going to involve my work (2' out from the walls at the front of the boxes, any island areas, etc.).

Next, lay the laser on its side and shoot a control line across the floor. While it is spinning, you might as well plumb these lines up the walls on either end of the line and mark the spot on the parallel wall that the laser is showing as the 90. Turn the laser to this 90 mark and the original floor point and mark again across the floor and up the walls. Now you have a general 3D set of bench marks to work from. Anything can be related to anything else in the entire space if you want.

I still shoot wall offsets; 4" is my favorite number. Check for the extremes or at least the extreme that eats into your space, because that is what usually becomes the wall face plane.

For me the high spot of the subfloor is where I work from usually. The flooring needs to be brought up to level with my work. Don't rush your survey, or your layout. Anything you catch early is a money saver. And even if another trade is not paying you for your work, you might be better off sharing any problems that you find with them. Like say if you are raising your work to match the 3" high spot in the floor on the other side of the room, you might want to tell the plumber, so that his stub outs work, and tell the electrician, so that he can move his receptacles out of your backsplash.