How We Convert a Crawl Space into a Full Basement (Step by Step)

On this project in Westminster, Colorado, we helped our clients overcome their worries about structural integrity by showing them our detailed, engineered approach to foundation underpinning. Because this home sits on expansive soils, the structure is supported by caissons drilled down to bedrock. This unique setup allowed us to excavate the entire area at once without undermining the home, eventually increasing the ceiling height from the 7-foot range to a spacious 8'6" 00:00 – 01:02: Introduction to the Westminster, CO project and addressing homeowner concerns regarding structural integrity. 01:02 – 01:40: Initial excavation and installing helical pier steel anchors to support the foundation. 01:40 – 02:07: Cutting the concrete wall and using conveyors to remove dirt by hand. 02:07 – 03:08: Explaining the role of caissons and cardboard voids in managing expansive soils. 03:08 – 03:47: Preparation for new walls, including laser leveling and back forming against dirt. 03:47 – 04:27: Installing rebar, epoxy, and moisture barriers followed by structural engineering inspections. 04:27 – 05:15: Pouring 4,000 psi concrete via line pump for a true underpin. 05:15 – 05:40: Installing perimeter drains and sump pumps for proper drainage. 05:40 – 06:01: Laying the pea gravel, vapor barrier, and pouring the four-inch concrete slab. 06:01 – 06:32: Comparing the new 8'6" ceiling height to the original 7-foot basement. 06:32 – 06:55: Beginning the finishing phase with 2x4 framing and floating walls. 06:55 – 07:19: Using steel I-beams for rigidity instead of intrusive counterforts. 07:19 – 07:40: Moving into mechanical, electrical, and plumbing rough-ins for a turnkey finish.