Replies

1. 
   steam | Feb 15, 1999 01:28pm | #1

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   What are the dimensions of the room?? You will have to consider how the drywallers will be hanging thier sheets. If they can hang the 16' sheets wall to wall w/o a butt joint being off an inch should not matter. if they can't make the joist square and forget the walls. Good luck!!!!!!

2. 
   Tom_Morgan | Feb 15, 1999 09:57pm | #2

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   I always thought I was a decent carpenter, but this one thing has me stumped. We are laying new celing joists under roof rafters, between two top plates, an interior bearing wall and an exterior bearing wall. The joists run from a ledger of the interior wall to the top of the top plate of the exterior wall.

   I had them laid out nice and neat, 16 oc, and at the end of the day, I was off over an inch. It seems that the interior bearing wall is not square to an exterior side wall, and is not parallel to the exterior bearing wall. I did not do this framing. It is original.

   I am trying to use a framing square, and can get these joists right. Do I keep them parallel to the side walls, and out of square, or square to the ledger and at an angle to the side walls. Parallel is far easier than square, because the distance is great, and the slightest change at one of the ends, makes the darn thing out of square.

   Thanks for everyone who responds.

3. 
   Guest_ | Feb 15, 1999 09:57pm | #3

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   Tom, welcome to the world of remodeling, where nothing is level, square or plumb. I am actually not surprised, as most builders, especially 40 years ago, did not lay out the exterior, let alone interior walls square.

   The foundation CMU was laid out on string lines, which was more or less square and the bottom plates merely followed that. The interior partition walls were laid out with a tape measure and if they were feeling real good, a framing square. So I assume on any remodel job that nothing is sqaure, and go from there.

   The key is to get the joists square to the ledger by forming a box with the two outside joists.

   Steam's post hits the nail on the head (pun intended). The key is to get the drywall to line up and break on a joist, without trimming. You can trim at the exterior walls, but not at the joist. I could care less whether the joist is square or parallel or any of that nonsense. They merely have to be square and parallel to themselves.

   I start with the two outside joists. As steam suggests, figure out how long your drywall is going to be (longer is better) and plan on your first joist more than 3 inches, but less than 16 inches from the sidewall. Use a tape or a construction calculator (believe me they will come in handy) and calculate where your last joist will end up. Again, you want it less than 16 and more than 3 inches. Adjust the whole layout in or out until you get that layout right.

   Tack the two outside joists in place on one side of the room, presumably to the top plate or a ledger. Use Simpton ties. Let the other end rest on the other top plate for now.

   Measure the span between these two joists at the ledger. Bring the loose ends together until the measurement is the same. You now have a square which is parallel, but not square, unless you are very lucky.

   Measure the square's diagonals, and move the loose ends right or left together the same distance until the diagonals are the same. Repeat the procedure one more time to make sure the two joists are indeed parallel and square to the ledger. Nail 'em.

   Lay out the rest of the joists 16 oc. Good Luck, Tom!

   Hey does anyone know of a machine, like a laser level that could be nailed or placed on a ledger and will shoot a 90 degree dot of light on to an opposing top plate? I know a transit would work but thats a little high up. I know laser levels will shoot a line that is level, but not necessarily 90 degrees?