Before design · before bid
Pre-construction Ground Checks
Find the rock before it finds your budget.
We put a rig and crew on your site for one to three days. We probe to rock at the locations that will carry your foundation, drill a test shaft, and proof-test anchors or piles. Then we hand you the factual field logs and what the foundation will cost to install.
- on site, with our own rig and crew
- 1–3 dayson site, with our own rig and crew
- from demobilizing to factual field logs
- 48 hoursfrom demobilizing to factual field logs
- of the fee credited if we install
- 50%of the fee credited if we install
- Rock probe
- Test shaft
- Proof test
- Obstruction
Illustrative layout · not project data
Why check first
Top of rock is the number that moves a foundation bid.
A boring every few hundred feet tells your engineer the geology. It doesn’t tell anyone where rock is under pier 37. Bid on an interpolated number and the difference comes back as a longer socket, a switch from driven pile to drilled pier, or predrilling every post. One change order like that can cost more than the whole probe program.
- Typical spread of depth to rock within one town
- 34 ftSpread of depth to rock across the middle half of logs in a typical New England town.
- Towns where rock is both shallow and deep
- 896 / 1,199Towns where at least 1 log in 10 hits rock within 10 ft and at least 1 in 10 goes past 50 ft.
343,355 well and boring logs that reached rock; towns with 25+ logs. Ground Truth bedrock data
The field program
Pick the checks your foundation needs
Combine any of them into one program, laid out on your planned foundation locations and your existing boring plan.
Rock probes & top-of-rock mapping
Probes drilled to refusal at your planned pier, caisson or post locations, so each foundation gets a measured depth to rock instead of one interpolated from a boring hundreds of feet away.
- Depth to refusal
- Drill rate
- Water
Obstruction probes
Probes along a pile line, wall alignment or carport row to find boulders, buried foundations and debris in old fill before the production rig does.
- Depth of hit
- Extent
- Photos
Logged test shaft
One production-size shaft, drilled with production tooling and logged top to bottom: whether it needed casing, how the sidewall stood, what water came in and how long the rock socket took.
- Casing
- Sidewall
- Inflow
- Socket time
Anchor & pile proof tests
Proof or performance tests on a sacrificial anchor, helical or pile, run with a calibrated jack and gauge to the loads and hold times your engineer specifies.
- Load
- Movement
- Hold
How it runs
From your plans to field logs in four steps
Step 1: Scope
Send the site plan, the planned foundation layout and any borings. We lay out probe and test locations with your engineer and quote a fixed program.
Step 2: Probe & test
One to three days on site. Utility mark-outs first. Your engineer is welcome to log alongside our crew.
Step 3: Field logs in 48 hours
Depths, refusal, water, drill rate, obstructions and photos for every location, plus our installed-cost range for the foundation as drawn.
Step 4: Credit toward install
If we’re awarded the foundation work, half the program fee comes off the install contract.
Deliverables
Factual field data your engineer can use
- A log for every probe: depth to refusal, drill rate by interval, water, obstructions
- Test-shaft log: casing, sidewall behavior, water inflow, time to socket
- Proof-test readings: load steps, movement, hold times, jack and gauge calibration
- Photos at every location
- An as-drilled plan marking each location on your site plan
- The probe data as a spreadsheet, ready for your engineer
- Our installed-cost range for the foundation as drawn
What stays with your geotechnical engineer
We’re a drilling and foundation contractor, not an engineering firm. We record what the ground did; your engineer of record decides what it means.
- Interpretation of the ground or its classification
- Bearing, capacity or design values
- Foundation design or recommendations
- Sampling and lab testing (that’s a boring program)
Field log · rock probes
Sample · illustrative values
- Site
- Carport, rows A–C
- Datum
- Existing grade
- Method
- Probe to refusal
- Logged by
- ESC field crew
| Probe | Refusal ft | Water ft | Min/ft rock | Notes |
|---|---|---|---|---|
| P-01 | 9.5 | — | 0:48 | Clean refusal |
| P-02 | 11.0 | 7.5 | 0:52 | — |
| P-03 | 6.0 | — | — | Boulder; offset 3 ft |
| P-03A | 14.5 | 8.0 | 0:55 | Offset probe |
| P-04 | 19.0 | 8.5 | 1:05 | — |
| P-05 | 26.5 | 9.0 | 1:10 | Soft seam 22–23 ft |
Who books it
For whoever carries the rock risk
- 01
Carport, BESS & substation EPCs and developers
Pier depths set by measured rock at your locations, before the racking or equipment pads are designed.
- 02
General contractors pricing ledge risk
A rock number you can defend at bid time, instead of a contingency or an exclusion.
- 03
Geotechnical engineering firms
Top-of-rock data between widely spaced borings, drilled at your locations and logged the way you specify.
- 04
Developers with ledge exposure
Know whether a site needs drilled piers before you close on it or commit to a foundation type.
Not ready to mobilize?
Start with a ground screen of every site.
Send 5 sites or 500. For each one we compile the nearest measured well and boring logs, the range of depths to rock they show, and a foundation-risk tier, so you know where a ground check is worth booking. Where there aren’t enough logs nearby, we say so.
About ground screeningGround screen · 4 of 60 sites
Sample · illustrative values
- Site 01Driven pile OK14 within 1 kmrock 38–85 ft
- Site 02Predrill likely9 within 1 kmrock 6–42 ft
- Site 03Drilled pier likely11 within 1 kmrock 2–9 ft
- Site 04Too few logs1 within 1 kmnot enough to call
Every tier comes with the logs behind it: distance, depth, source.
Frequently asked
Know the rock before you price it
Send the site plan and planned foundation layout. We’ll lay out a probe program with your engineer and quote it, typically one to three days on site, with half the fee credited if we install.