Screw anchor foundations and related interfaces for modular, manufactured and prefabricated structures
A foundation system for manufactured homes, prefabricated houses, and other structures. Multiple screw anchors are driven into the ground at the desired location of the structure. Preformed grade bars may be placed over the screw anchors to provide a modular foundation without pouring concrete or digging footers. Alternatively, adapters may be attached to one or more of the driven screw anchors to provide a pedestal to receive the grade bar or prefabricated sections of concrete.
1. A foundation system for modular and prefabricated homes comprising:
a plurality of truss foundations, each truss foundation comprising a pair of legs that are driven into supporting ground and angled towards one another; and
a precast slab section that is attached to the plurality of truss foundations at pre-formed through-holes, wherein each pre-formed through-hole comprises a box containing a transfer bar, slidably positioned within the box, and a sealant pan above the transfer bar with a waterproof membrane in the sealant pan.
2. The foundation system according to claim 1 , wherein each truss foundation comprises an adapter, the adapter joining each pair of truss legs and including a pedestal for supporting the precast slab section.
3. The foundation system according to claim 1 , wherein the transfer bar includes at least one slot for receiving an anchor bolt.
4. The foundation system according to claim 1 , further comprising a volume of water blocking material in each pan above the waterproof membrane.
5. The foundation system according to claim 1 , further comprising a volume of bentonite positioned in each through-hole beneath the transfer bar to prevent the ingress of water.
6. The foundation system according to claim 1 , further comprising a plurality of lift points formed in the precast slab section.
7. A method of forming a foundation comprising:
driving a series of screw anchors into supporting ground at predetermined positions;
attaching adapters to the screw anchors;
placing a pre-cast slab on the adapters so that the adapters align with holes formed in the pre-cast slab;
securing the pre-cast slab to the adapters; and
placing a pan in each hole formed in the pre-cast slab, lining the pan with a waterproof membrane, and filling the lined pan with a water blocking material to prevent water from passing from under the pre-cast slab to above the pre-cast slab via the holes.
8. The method according to claim 7 , wherein attaching the adapters to the screw anchors comprises attaching an adapter to an above-ground end of each driven screw anchor, the adapter including a pedestal for supporting the pre-cast slab.
9. The method according to claim 7 , wherein driving the series of screw anchors comprises driving the series of screw anchors in angled pairs at predetermined positions under an intended location of the pre-cast slab.
10. The method according to claim 9 , wherein attaching adapters to the screw anchors comprises attaching an adapter to an above-ground end of each angled pair of screw anchors, the adapter including a pedestal for supporting the pre-cast slab.
11. The method according to claim 7 , wherein placing the pre-cast slab on the adapters so that the adapters align with the holes formed in the pre-cast slab comprises aligning transfer bars in each hole with a pedestal formed on each adapter.