Layout for Walls

Study the floor plan carefully; review all the basics, e.g. every corner needs a corner post, every wall intersection needs a tee, every window and exterior door needs a 2x10 header. Habitat uses all the same windows and door sizes in every house with few exceptions so that header sizes and rough openings are pretty standard.

Lay out exterior walls first, then interior walls. Before any layout, though, verify that the deck is SQUARE and that full length and width of the floor deck are correct. If there are errors in the dimensions, refer to troubleshooting guide in"Problems We've Had"

Snap long chalk line for exterior walls. Proceed sequentially around perimeter, marking interior wall intersections and noting locations of windows and exterior doors. Use 2x4’s 16 feet as long as wall layout plates for exterior walls. With a helper, measure distances on plates, marking each stud location on both top and bottom plates; for wall sheathing continuity, it is best to keep 16" O.C. for the entire length of the building…so that even though there may be several wall segments, when they are conjoined, one stud is always 16" O.C. from the last stud.

As you lay out in sequence, mark down number and sizes of headers, how many tees, corners, jacks, and cripples are needed so that you develop a "cut list" as you go. As stud/header marking of one wall segment is completed, it is ESSENTIAL that you mark or identify the top and bottom wall plates for that particular segment with an identifying letter in a permanent marker. The same identifying letter is also marked directly on the deck on the paper house plan, on the floor plan. Interior wall plates are marked with numbers to distinguish them from exterior plates and are generally laid out form 2x4’s 12 feet in length.

Always refer to floor plan as you mark where interior walls butt up against exterior walls. Crayon or markers are used directly on the floor deck to identify start and end of a particular segment. Chalk lines are snapped the entree length of an interior wall, plates tacked directly on these lines and stud layout is made directly on the plates. Marks to identify each wall are made (as above) on the deck, the plates and the plan.

All chalk lines are preserved with line-saver spray so that on raise-the-roof day, rain will not erase the lines. Pay attention also to the SEQUENCE OF WALL ERECTION and mark it down so that the walls are stacked in the proper sequence; ask yourself which wall is the first wall we’ll set up? THAT WALL should be on the top of the pile. Also, during setup of exterior walls, remember to leave out one exterior wall segment so that interior walls may be passed through for convenience.

Prior to floor joist layout, beam/girder must be in place, square and level; also pressure-treated sill plates must be bolted down accurately and all rim joists installed. Familiarize yourself with a) the location of the rear interior storage space and b) the location of the plumbing wall and toilet. Contrary to popular belief, one does not begin floor joist layout from front to rear, marking 16" o.c. Rather, we start at the plumbing wall(s). Estimate where the toilet(s) will be and place your first two floor joists in such a way as to leave a 13" clear space for the toilet drain. No joists on or over the plumbing wall. After marking these two critical floor joists, proceeds 16" o.c. each direction till you comes to the end. This keeps the plumbers from cursing you and then cutting a floor joist.