Excavation Services in Roy, Utah

Excavation services are for homeowners who need earthwork done before a construction, drainage, or hardscape project can start — or who need site corrections on an existing property where grading, drainage paths, or soil conditions are causing problems.

You may need excavation if:

(i) A new foundation, slab, retaining wall, patio, or addition requires the site to be dug, leveled, and compacted before construction begins. (ii) Drainage is failing because the yard slopes toward the house, water pools against the foundation, or existing swales and discharge paths no longer move runoff away from the structure. (iii) Utility trenching is needed for new service lines, drainage piping, or subsurface connections that require controlled-depth digging with proper backfill. (iv) The existing grade has shifted, settled, or eroded enough that the property needs meaningful soil correction before it can support other improvements.

Cornerstone operates as the excavation contractor within the Restoration, Waterproofing and Structural Services family. Our role is the earthwork itself — digging, grading, trenching, compaction, backfill, and spoil handling. Geotechnical engineering, land surveying, and licensed utility installation are handled by the specialists those scopes require, and we coordinate with them when your project calls for it.

Excavation is not one job — it is a category of earthwork that changes shape depending on what the site needs and what is being built next. The scope depends on soil conditions, depth, access, and which follow-on trade or project the excavation supports.

Work that falls inside this scope:

(i) Rough and finish grading to establish drainage slope, level building pads, and correct surface-water flow patterns across the yard or around the structure. (ii) Trenching for drainage piping, drain tile systems, downspout discharge lines, and utility-support routes at controlled depth and grade. (iii) Foundation excavation for footings, slabs, additions, and below-grade structures where the dig must reach specified depth with stable, compacted bearing surfaces. (iv) Soil removal, import, and replacement when existing material is unsuitable — organics, uncontrolled fill, saturated clay, or debris that cannot support the intended load. (v) Backfill and compaction after foundation work, drainage installation, or utility placement, with material selected and placed to meet the structural or drainage requirements of the project. (vi) Drainage swale construction, berms, and surface-water redirection where the property needs grade-based runoff control without subsurface piping.

Work that falls outside this scope:

(i) Geotechnical engineering, soil testing, and bearing-capacity analysis — these require a licensed geotechnical engineer whose report informs excavation depth, compaction requirements, and material specifications. (ii) Land surveying and boundary or elevation certification — these require a licensed surveyor and are typically completed before excavation begins. (iii) Licensed utility installation — gas, water, sewer, and electrical connections are installed by the appropriate licensed trades; excavation provides the trench and backfill support. (iv) Environmental remediation — contaminated soil, underground storage tanks, and hazardous material handling require environmental specialists.

Representative project conditions along the Wasatch Front:

(i) Lake Bonneville clay — the dense, alkaline clay that covers much of Davis, Weber, and Salt Lake counties absorbs water slowly, expands significantly when wet, shrinks when dry, and resists compaction unless it is processed in controlled lifts. This shrink-swell behavior is one of the most common reasons excavation work on the Wasatch Front takes more planning than the same project would on sandy or loam soils. (ii) Rocky alluvium on bench properties — as sites move east toward the foothills, soil transitions to quartzite and limestone fragments mixed with sandy gravel. Upper-bench lots frequently hit solid rock within three feet, which changes equipment needs, production rates, and cost. (iii) Frost-line depth — minimum frost depth across Davis, Weber, and Salt Lake counties is typically 30 inches. Any footing, pier, or below-grade structure must reach below that line. Clay holds water and freezes more aggressively, so actual excavation depth often exceeds the minimum. (iv) High water tables in lower-elevation areas — properties near the Great Salt Lake, Farmington Bay, and low-lying areas in western Davis County can encounter groundwater within a few feet of grade during spring snowmelt, which affects trench stability, dewatering requirements, and backfill timing.

This page covers three primary categories of residential excavation. Most projects involve one category; larger projects may combine two or all three.

3.1 Site Preparation and Grading

Site prep is the earthwork that shapes the property before construction begins. This includes clearing vegetation and debris from the work area, establishing rough grade for drainage and building-pad elevation, cutting and filling to level slopes or create flat working surfaces, and finish grading after construction to establish final drainage flow and restore the yard surface. Grading corrections also apply to existing properties where settlement, erosion, or poor original grading is directing water toward the foundation instead of away from it.

3.2 Trenching and Below-Grade Support

Trenching is controlled-depth excavation for specific subsurface installations. Common residential trenching scopes include drain tile and foundation drainage piping, downspout discharge lines routed away from the structure, utility support trenches for water, sewer, gas, or electrical service (with installation by the appropriate licensed trade), and retaining wall footings where the wall foundation must sit below frost line on compacted bearing material. Trench width, depth, sidewall stability, bedding material, and backfill method all depend on what the trench is supporting. A drain tile trench at four feet does not use the same approach as a utility trench at six inches.

3.3 Foundation and Structural Excavation

Foundation excavation is the deepest and most specification-driven category. This work supports new construction footings and slabs, addition foundations that must tie into existing structures, below-grade walls and basement-level access, and pier or post-hole excavation for decks, pergolas, and structural supports. Foundation excavation typically requires the tightest tolerances — the bottom of the dig must be level, at the correct depth, and sitting on material that can carry the structural load. When a geotechnical report specifies bearing capacity, compaction density, or material replacement, those specifications govern how the excavation is performed and verified.

The more site information available before the estimate visit, the more accurate the initial scope and pricing conversation will be. These are the inputs that affect how excavation work is planned:

(i) What the excavation supports — knowing whether the earthwork is for grading, drainage, a foundation, a retaining wall, a slab, or utility access determines depth, tolerance, and equipment needs. If the excavation is part of a larger project, share the overall scope so the earthwork can be sequenced correctly. (ii) Blue Stakes utility locate — Utah law requires a Blue Stakes 811 utility locate request at least three business days before any excavation begins. Markings are valid for fourteen calendar days. We coordinate this as part of the project, but if you have already requested a locate or have utility records, those help during the estimate. (iii) Site access and equipment path — gate widths, fence lines, slope, neighboring structures, overhead lines, and driveway limitations all affect which equipment can reach the dig area. Tight residential lots often require smaller machines with longer cycle times. (iv) Existing hardscape and landscaping — patios, walkways, retaining walls, irrigation lines, mature trees, and garden structures in the work zone or equipment path may need to be removed, protected, or restored after excavation. Identify anything you want preserved. (v) Soil and site history — if you know the soil type (clay, rock, fill), whether the property has flooded, whether previous work was done in the same area, or whether any environmental conditions exist, share that information early. On the Wasatch Front, soil can change significantly within the same lot. (vi) Plans, surveys, or engineering reports — if the project has architectural drawings, a geotechnical report, a surveyor's plat, or a grading plan, bring those to the estimate conversation. They define the excavation specifications and reduce the assumptions we need to make.