Spruce plywood is an essential component in home repair, construction, and remodeling projects. While it does contain wood knots, these are cosmetic only and do not affect strength and performance. This wood is suitable for use in walls and is strong enough to serve as roofing or flooring plywood. The waterproof adhesive used to sandwich the layers of this material makes it able to withstand humidity and other moisture. The standard spruce plywood is compatible with nails, wood screws, staples, and other fasteners.