Sheathing, flashing, and insulation is the last step before moving on to the finish work in the custom home building process. However, depending on the time of year and the climate in your area, your contractor may choose to sheath the house before installing the electrical, plumbing, and HVAC systems.
These operations represent basically the process of covering the framing, offering protection from the elements, but leaving it open makes for easier access. Your construction crew encloses the house during the sheathing process. In this process the crew applies a covering material to the outside of the framing.
The sheathing procedure serves several purposes, adding shear strength to the walls, providing backing for the siding, and stabilizing the studs from bending under the load and warping with the
weather.
The majority of sheathing nowadays is asphalt-soaked fiberboard. A composite material commonly referred to by its brand name Built-rite, this fiberboard is the most common and cheapest insulator for sheathing. Other newer and more expensive materials may be available for sheathing. Discuss these options with your contractor as well as the timing of sheathing in your project.
There are special nails used in the process, which have protective plates to keep from puncturing the outer skin of the sheathing when attaching to the studs. The crew nails wall sheathing to the stud vertically about every foot. Over the top of the sheathing, a permeable vapor barrier is applied, underneath the siding. This barrier keeps moisture out but allows air to pass. Make sure all seams are taped, and windows wrapped with window wrap.
When it comes to the roof, sheathing is generally made of the weatherproof plywood. Your roofing sub needs to secure roof sheathing along the rafters or trusses every 8 inches. When sheathing the roof, the crew needs to allow for whatever type of roof ventilation that you plan to use. The crew may need to leave spaces at the ridges and cut holes for extruding vents and skylights. Any items punched through your roof need to have flashing, a metal stripping nailed in place and sealed or caulked to prevent water from leaking into your home.
After the roof sheathing, contractors commonly stack the roofing material on it in preparation for the next phase of construction, thus providing the appropriate weight to the roof sheathing, preventing unnecessary expansion and warping.
Immediately after the sheathing process, it’s time to roll out the insulation. By then, you and your architect should have already discussed the type of insulation for your house during the design phase. Your construction crew can easily roll the commonly used blanket insulation out into the walls and ceilings.
Walk the house with your contractor and discuss which areas can handle hand-packed insulation and additional soundproofing. Make sure that you have the plumbing and ductwork completely covered and that the insulation doesn’t cover any vent holes.
Things to Check after Sheathing, Flashing, and Insulation
After all these operations, you need to make sure that your house is bundled up just the way you want it. Use the following pointers to check the quality of the work done:
- Your contractor has attached sheathing every foot in the middle of the panel, every 6 inches on the edges vertically along studs, or every 8 inches for roof deck.
- No nails are loose or extended.
- All gaps are taped over a quarter inch.
- Skins of sheathing aren’t torn, ripped, or broken by nail heads.
- All skylights, chimneys, and vent pipes are sealed and flashed.
- All wall insulation is securely fastened.
- All windows, doors, cracks, and joints have hand-packed insulation, as appropriate.
After the sheathing, flashing, and insulation step, you are ready to start painting the house and give it the look you wanted from the beginning.