Expert: Bruce E. Johnson - 10/1/2009

Question
I've removed the plaster and slats from the ceiling and started putting up the drywall but the ceiling is not level.  What can I do to level the entire thing at one time. Someone mentioned string but I don't know how to use the string. Can you explain this to me

Answer
Hi Cami, oftentimes you can strip ceiling joists with 1x2, 1x4, metal high hat, or resilient channel.  By stripping the ceiling across the joists at 24" on center you can use the strips to level the ceiling.  It becomes obvious when doing the stripping which joists are high and which ones are low.  You shim the stripping so that it is level.  Cedar shims work great.  You can buy a small bundle of shim shingles at any big box store like HOme Depot and Lowes.. Metal high hat and resilient channel are great too.  They are screwed to the ceiling joist to give you a nice straight surface.  Resilient channel is nice because it is Z shaped.  You screw on one leg of the Z to the joist.  The other leg of the Z you screw your drywall to.  Because the resilient channel is Z shaped it acts as a spring so to speak and automatically straightens the joist plane.  Stringing the joists is an old method of checking the joists.  Basically you take a 3/4" block of wood and nail it to a joist at the far end of the room.  Attach your string to a nail or screw in the middle of the block.  Do the same thing on the other end of the room and pull the string as tight as you can.  The string should now be approximately 3/4" below the joists.  Using a 3/4 block of wood you can slide it alongside the string at each joist and see if the joist is high or low.  I hope this information helps, please feel free to write again regarding this or other matters, sincerely bruce e johnson..bejohnsonconsulting.com