The Ultimate Guide to Hole Prep for Lockwood Precast Products

Cisterns • Septic Tanks • Egress Window Wells • Utility/Meter Vaults • Steps & More  

At Lockwood Precast in Billings, Montana, we’ve poured 5000 PSI concrete since 1963. From cisterns to septic tanks, egress wells to meter vaults, every piece is built to last generations—but only if the hole is prepped right. This one-stop guide covers some Lockwood Precast products with product-specific specs, common mistakes, and a print-ready checklist.

1. Start with the Lockwood Installation Drawing

Every item includes a job-specific drawing. It lists:

• Exact footprint

• Inlet and outlet height (septic)

• Riser/access locations

  
  

Lost it? Call (406) 245-4635—we’ll email you a new one!

2. Excavate with Product-Specific Over-Dig

3. Gravel Base: Product-Specific Depths & Materials

Never use pea gravel—it shifts and settles. Use ¾" minus only!

4. Level Within ⅛" — Laser Every Time

• Use a laser level and a 4-ft straightedge every 2 ft.

• Maintain a maximum tolerance of ⅛" across the entire base.

• Pro Hack: Crown the center 1/16" high on tanks—weight settles it flat.

  
  

5. Boom Truck Access = Non-Negotiable

Our boom trucks with outriggers require:

• Firm, level ground within 6 ft of the hole.

• Clear access to the hole. No debris or dirt piled where the truck needs to be.

• 20 ft vertical clearance (no trees, power lines, eaves).

• Outrigger spread: 18–20 ft wide.

• Flag/mark the drop zone before we arrive.

  
  

6. Final Hole Prep Checklist (All Products)

• Drawing reviewed—dimensions + gravel depth confirmed.

• Over-dug per spec (16–18" for tanks, 12" for wells, 8" for vaults/steps).

• Gravel base installed & compacted (3–6" for cisterns/septic, 6" for wells/vaults, 4" for steps).

• Base level within ⅛" (laser-verified).

• 1% slope to daylight (egress wells & drainage-critical items).

• Boom truck zone cleared (20 ft overhead + outriggers).

• 811 called—utilities flagged.

• Grade strings pulled at exact bottom elevation.

• Inlet/outlet stubs 6" into hole (septic tanks).

• If installing a drain pipe, daylight it 6" below base (egress wells). Text a photo to (406) 245-4635—we’ll confirm before dispatch.

  
  

Common Hole Prep Mistakes by Product

Ready for a Lifetime Lockwood Install?

A perfectly prepped hole means a fast set, zero call-backs, and happy clients! Need a custom drawing or site walk? Call (406) 245-4635—we’ll send product-specific specs with every quote.

Lockwood Precast: Montana-made. Contractor-trusted. Built to last.

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