Slab and Foundation for Our Uber Man Cave is the next phase or our construction. As with any structure, a new garage foundation plays a crucial role in the integrity of the building above: A quality foundation will last many years, but a poorly laid one can cause many headaches down the road. Rarely considered a do-it-yourself project, laying the foundation for our Uber Man Cave required good planning, adherence to local code, and careful consideration of future uses for the finished space. Plan on inspections along the way, as well. A garage foundation is typically constructed of concrete block or a poured concrete wall. First the site is cleared or scraped and footing trenches are dug below grade according to code. The height of the concrete foundation wall is usually determined by the size of the structure above. Steel reinforcing helps the foundation wall bear stress while mechanical vibration consolidates the concrete to eliminate voids and air bubbles that might weaken the concrete. Anchor bolts are installed in the concrete foundation to secure the garage walls to the foundation. The location and frequency of anchor bolts on the foundation wall is determined by local code. Once the footings and foundation walls were in place, our concrete slab was poured and formed inside the foundation frame. Depending on the region and the garage plans, this slab can be poured on a compacted subgrade, which can include sand or gravel. A vapor barrier and insulation are often positioned upon the subgrade, with wire mesh and steel bars for reinforcement.