Normal backer layout has the layout marks for a backer aligned with the position of the wall that will be nailed into the backer. This isn’t always the case, however. Sometimes it is better to move the backer so it does not line up. For example, you might have a door next to the backer, with only 21/г" between the backer and the rough opening of the door. Instead of having a Ш" trimmer and a 1" king stud, you just attach a Ш" trimmer to the backer and move it over У2".
The best way to mark this on the wall layout is to mark both positions of the backer. The first position is where the backer would align with the wall, and the second is where the backer was moved and where it will be nailed. A good way to distinguish the two positions is to mark over the one line with a carpenter’s crayon (keel or lumber crayon). This layout information will help when the walls are nailed together. It will also help when you are cutting the double plate of the joining wall to overlap. (See “Backer Move” illustration.
It is important to be aware of special stud layouts, such as might be required for shower or bathtub center valves. Showers and tubs are typically 30" wide. Space must be allowed in the middle for the valves. It’s usually easy to find the center and then set a stud 8" on center each way. (See “Plumbing Studs” illustration.)
Recessed medicine cabinets are another special layout. If they require a 141/2" rough opening, they could fit between standard 16" O. C. spaces. More often than not, however, the design requires installation in a particular location that requires special layout.
Different types of siding require different types of backing. For example, bevel siding with a wide window will require an extra stud or extra backing along the window to attach the siding.
Often a beam or girder truss, or some other structural member, requires structural support all the way to the foundation, but that support is not shown on the plans. Check and lay out for upper floor structure support when laying out walls.
Another mark you might need to make on your walls is for location. If you have to move the plates to make room to build walls, then you need to mark the location for all the walls to make sure you know where they go when you are ready to build them.
It is best to use a crayon and mark a number and an arrow on each plate. The top and bottom plates will be marked with the same number. The arrows will point in the same direction as all the other walls that run in that direction. In addition to marking the plates, mark the number and the arrow on the floor next to the plates. (See “Plate location marks" photo.)
If you are laying out walls on a concrete slab, then you will have to contend with plumbing and electrical pipes. Before you start your layout, notch the bottom plate to fit.
