Good drainage, reliable waterproofing, and the right structural details yield a warm and dry basement living space.
The Southern Pine Council's "PWF Design and Construction Guide" contains an abundance of prescriptive data, including span tables, fastening schedules, and detail drawings.
All framing lumber and plywood used in ground-contact areas must carry a grade stamp identifying it as suitable for foundation use.
Plans for pressure-treated basement foundations with backfill depths of up to 86 inches can be drawn up by following prescriptive design tables. Deeper fill or other site-specific conditions that fall outside the scope of the tables will require a plan stamped by an engineer.
Although wood foundations have traditionally been supported by footings of carefully compacted gravel or crushed stone, a poured concrete strip footing can also be used.
The poured footing simplifies the process of snapping layout lines and provides a convenient surface for marking plates and assembling wall framing.
The top member of the doubled top plate can be assembled from conventional untreated framing lumber, lapped at the corner as in standard framing.