overlap sill-to-foundation joint with a minimum 2-inch overlap. I ended up sheathing the walls to overlap the bottom plate by about 3/4", and by doing so the top plate was isolated from the rest of the structure. I guess the main reason I asked this question is because I built a similiar project before in a high wind area. In either case, sheathing and siding should cover the joists. Do not apply vinyl siding directly to furring strips without sheathing, because the siding may conform around the furred areas causing an uneven appearance. Exterior wall sheathing strengthens the wall system, provides a nailing base for the siding, and gives a layer of protection against outside elements. Every top corner should have a top plate overlap. Exterior Wall on Slab Must Be Out on the Edge. Apply rigid sheathing to cover and level the furring strips. Building wall or siding flashing details at horizontal surfaces: Wall or siding connection to foundation top, porch floors, slabs: flashing materials, choices, installation details & specifications: this aritcle describes the cause, repair and prevention of leaks & rot damage at a wood framed wall that was not properly flashed and sealed at the wall bottom. (See Fig 2) And then gives Figure 2 as: Again, clearly showing a sheathing … When more than one length is needed to span across the bottom of a wall, overlap pieces at least 8 inches. It means the plate on top should run over onto the wall it connects to, forming a right angle and a solid connection. The water table should overlap the foundation by about 1 in. You don’t want the very outside surface of the wall to be flush with the foundation. As is the case for all detailing: think about the application. Liz snaps a line about an inch and a half below the wall sheathing and uses duct tape to mask the line. Wall height is sometimes confusing for DIYers because using 8’ studs with a double top plate results in sheathing that doesn’t quite cover the entire wall. Horizontal seams should overlap at least 2 inches and vertical seams a minimum of 6 inches. Not soon after, their were winds up … Related Links. If I offset the bottom of the walls the depth of the floor, it means a lot of clean up in the section detail. This prevents water from leaking under the bottom of the wall to the inside of the building. Cut a slit in the sheathing wrap along the entire length of the water table and slip the upper leg of the flashing under the wrap (see Illustration). Gauge the exposure. Should wall sheathing overlap foundation? Structural exterior wall sheathing ties framing studs together, making the walls resistant to … and be capped on top with either a preformed metal drip cap or a custom flashing installed under the sheathing wrap. Masking a line gives a clean finish. This piece should be applied directly to the wall sheathing using roofing nails. Consider a Wood Shed Floor - Treated Lumber Joists AND Plywood! In previous episodes, we installed wall sheathing and taped the seams between the panels. Wrapping should start at the foundation, or the base of the wall assembly, extending at least an inch past the wall-to-foundation intersection and continuing upwards like shingle installation with the higher course overlapping the lower. This episode focuses on another super-important place to detail the air barrier: where the walls meet the foundation. Re: Sheathing overlap. Exterior wall sheathing is either structural or non-structural. Basically, you have a sill plate on the foundation wall, 1" OSB subfloor directly on top of the sill plate (not sole plate as this is a crawlspace), 16" o.c stud wall, with OSB wall sheathing. An exterior wall must be placed on the outside edge of the slab so the exterior siding laps down and over the edge of the slab. The flashing must include a drip-edge to direct any water that runs down the drainage plane away from the bottom of the wall. protect lower part of wall sheathing with bituthane membrane. And be conservative in your estimation of the forces influencing your design. On the first floor, there are no exterior walls below, but there are foundation walls. It strengthens the walls of the house, provides a thermal and moisture barrier, and creates a surface on which the home’s exterior finish can be installed.