Concrete Machine Pits
Concrete machine pits are below-grade reinforced enclosures that recess equipment below the floor — required for elevator pits, scissor lifts, automotive service bays, conveyor returns, and heavy production machinery. We build machine pits across the Seattle area for manufacturing, warehousing, distribution, and automotive facilities, from elevator pits on new construction to retrofit lift pits cut into existing slabs.
Every pit project starts with the equipment specs: load rating, pit depth and clear dimensions, sump and drainage requirements, anchor-bolt patterns, conduit penetrations, and waterproofing needs called for in the geotechnical report. We work directly with the equipment supplier and the structural engineer of record so the finished pit matches the install drawings exactly — misalignment after the pour is expensive to correct and often delays equipment commissioning by weeks.
Machine pit types and specifications
The most common machine pits we build in the Seattle area: automotive lift pits (typically 18–24 inches deep, 2–4 feet wide), CNC and hydraulic press pits (2–6 feet deep with reinforcement designed for vibration loads), and vehicle inspection pits (4–6 feet deep with integral steps and floor drains). Wall thickness and rebar schedule are engineered to handle lateral soil pressure and any point loads from the machine above. Sump pits and floor drains are standard for most applications.
Waterproofing in Seattle's high-water-table areas
Many Seattle industrial sites - particularly around SODO, Georgetown, and the Duwamish Valley - have a water table within a few feet of grade. Before we break ground, we assess groundwater depth and plan accordingly. Deep pits may require dewatering during construction. Below-grade walls and floors are waterproofed with crystalline or membrane systems, with sump pumps as backup. A flooded pit is a production stoppage - waterproofing is not optional.
Industries we serve
We build machine pits for: automotive service shops, manufacturing and metal fabrication facilities, food processing plants, commercial vehicle fleets, and custom industrial build-outs throughout King and Snohomish counties. Contact us early in your facility planning - pit work is easiest to coordinate before other trades begin tenant improvements.
Frequently asked questions
What is a concrete machine pit and who needs one?
A concrete machine pit is a below-grade excavation with reinforced concrete walls and floor, built to house industrial machinery - such as CNC equipment, hydraulic presses, conveyor systems, or vehicle lifts - at a level that allows workers or equipment to operate at grade. Manufacturing facilities, auto shops, and industrial warehouses are the most common users.
How much do concrete machine pits cost in Seattle?
Machine pit costs in Seattle vary significantly based on pit dimensions, depth, reinforcement requirements, waterproofing needs, and site access. Smaller pits (e.g., automotive lifts) may start around $5,000–$15,000; large industrial pits with sump systems and thick structural walls can run $50,000 or more. An on-site assessment is required for accurate pricing.
What permits are needed for a machine pit in Seattle?
Concrete machine pit construction in Seattle requires a building permit from SDCI. Depending on depth and location, a geotechnical report, structural engineer drawings, and groundwater or shoring plans may be required. Commercial tenant improvements with machine pits may also trigger mechanical and electrical permit reviews. We work with your team through the permit process.
How long does machine pit construction take?
A typical concrete machine pit project takes 2–6 weeks depending on depth, size, and site complexity. Excavation, shoring (if required), forming, reinforcement placement, concrete placement, and waterproofing must be completed in sequence. Deep pits in Seattle's high-water-table areas may require dewatering, which adds time and cost.
How should a concrete machine pit be waterproofed?
In Seattle's high-precipitation environment, machine pit waterproofing is critical. We apply crystalline or membrane waterproofing systems to below-grade concrete walls and floors to prevent groundwater infiltration. Sump pumps and interior drain systems provide secondary protection. Properly waterproofed pits should be inspected annually and re-sealed if cracks or moisture intrusion develop.
