If you are planning a new build in Lethbridge, basement excavation is where the project moves from drawings to dirt. This guide walks you through each stage from the first soil test to the final grade so your foundation pour is clean, accurate, and ready for trades. We will use simple language and keep the focus on what matters most on Alberta sites.
Step one: Soil testing and site review
Before any bucket hits the ground, a geotechnical report confirms soil type and bearing capacity. On many Southern Alberta lots you will see clay, sand, or a mix. The report guides footing depth, over dig decisions, and any need for engineered backfill. Your contractor also reviews access for machines, haul routes for spoil, and space for stockpiles without disturbing neighbors or city property.
What you get
• Clear soil recommendations
• A plan for access and spoil handling
• A rough schedule that fits your foundation timeline
Step two: Permits and utility locates
The builder pulls the required permits and requests utility locates for gas, power, water, sewer, and telecom. Locates protect everyone and set safe no go zones. If a private line exists on the property, a private locate is arranged. Only after all markings are in place does excavation begin.
What you get
• Confirmation of safe dig areas
• No surprises with cut lines or service strikes
Step three: Layout and elevation checks
Survey stakes, string lines, and laser levels set the footprint and finished floor elevation. In Alberta, frost and drainage are key, so elevations are chosen to protect the foundation and move water away from the home. The crew confirms setbacks, property lines, and access widths for machines.
What you get
• Accurate layout that matches plans
• Elevations that protect against frost and water
Step four: Stripping and the dig
Topsoil is stripped and set aside for later landscaping. The crew excavates to plan depth with smooth, square walls and a level base. In some soils an over dig is used so the bottom can be rebuilt with engineered material. If water shows up, sumps and pumps control it so the base stays firm.
What you get
• A clean, stable hole at the right depth
• Dry working conditions for formwork and footings
Step five: Subgrade prep and inspections
The subgrade is checked for soft spots and compacted. A gravel layer is placed where needed to create a uniform base. The builder and inspector review depth, setbacks, and bearing conditions before forms go in. Any changes from the soil report are noted and addressed right away.
What you get
• A uniform bearing surface
• Pass ready conditions for footings and walls
Step six: Drains, waterproofing, and backfill plan
After the pour, weeping tile and sump connections are installed at the footing. The foundation is waterproofed or damp proofed according to plan. Backfill is placed in measured lifts and compacted so it supports sidewalks and driveways later. Clean gravel beside the wall and fabric where specified keep drains working for the long term.
What you get
• A dry basement plan that actually works
• Backfill that will not settle under concrete or decks
Step seven: Rough grade and final grade
Once backfill settles and exterior work is complete, the yard is shaped to shed water away from the house. Final grade follows city standards so that grass, sod, or rock can go in without pooling water against the wall. The set aside topsoil returns to the yard for landscaping.
What you get
• Positive drainage away from the home
• A tidy, build ready site for the next trades
Safety and quality controls you should expect
• Shoring, benching, or sloping in deeper or unstable soils
• Daily checks for water, wall stability, and safe access ramps
• Laser and GPS checks on depth and elevation
• Photo and measurement records for your file
Cost drivers to plan for
• Soil type and groundwater
• Depth of dig and over dig needs
• Haul distance for spoil and gravel
• Tight access or restricted street parking
• Weather delays during wet or freeze thaw periods
Frequently asked questions
How long does basement excavation take?
Most single family digs are measured in days, not weeks, once permits and locates are complete. Soil conditions, access, and weather set the pace.
Do I need an over dig
Only when soils do not meet the bearing requirement or the report recommends a rebuild. A controlled over dig with engineered backfill can save headaches later.
What happens if we hit water
The crew installs temporary sumps and pumps and may add a gravel working pad. The final drainage system and waterproofing are adjusted to match reality on site.
When is it safe to backfill
After the foundation meets specified cure and the waterproofing and weeping tile are in place. Backfill happens in lifts with compaction to protect future concrete and landscaping.
How much slope should final grade have
Your city standard will set this. The simple rule is to carry water away from the foundation for several meters. Your contractor will set and confirm this with a laser.
Why choose a local crew for basement excavation Lethbridge
Local teams understand our soil mix, wind patterns, and inspection routines. They know how to manage coulee slopes, gumbo after a rain, and quick weather changes. That local experience shows up in a cleaner dig, a better base, and fewer surprises for your build.
Ready to plan your basement excavation in Lethbridge
Reach out for a site visit. We will review your plans, confirm the scope from soil test to final grade, and give you a clear, fixed scope proposal that keeps your foundation pour on schedule.