Why HDPE for Underground Electrical Duct Bank Spacers

Material choice for duct bank spacers is not cosmetic. The spacer sits between conduits inside a concrete-encased bank for the life of the installation. Blue Ridge Thermoforming (BRT USA) CNC-routes those spacers from HDPE sheet in Greenville, SC. Here is why HDPE is the material on the page, and how fabrication differs from molding a catalog chair.

Non-conductive role in the bank

HDPE sheet does not carry current, which is why it is used between conduits in a concrete bank. The spacer’s job is geometry: hold and space the conduits. It is not a grounding path unless the drawing specifically calls for a ground-wire hole through the board. Keeping the sheet non-conductive supports that separation role without introducing a metallic grid into the pour.

BRT does not publish dielectric ratings or invent electrical clearances. Electrical design stays with the engineer of record. Fabrication follows the drawn hole pattern and spacing.

Chemical resistance underground

Live product copy states that HDPE resists many chemicals encountered in underground electrical work. Soil chemistry, concrete chemistry, and jobsite exposure still vary by site. Ask BRT which virgin or reprocessed grade fits the thickness on your print rather than assuming one commodity sheet covers every specification. Soft language is intentional: underground environments differ, and the right grade is a discussion, not a chemical-resistance certification.

Sheet grades: ask, don’t assume

Typical boards are 3/8 in and 1/2 in HDPE sheet. Virgin and reprocessed grades may both be options depending on the print and the application. Tell us:

• Thickness called out (or preferred)
• Any owner or engineer material note on the civil/electrical package
• Quantity and whether boards ship to the jobsite or into staging

We will recommend a grade that fits the thickness and the job rather than locking a single brand-name resin into every quote.

CNC routing vs molding

BRT duct bank spacers are CNC-routed from sheet. They are not thermoformed and not injection-molded catalog chairs. Routing from sheet means:

• Hole OD matched to each conduit on the schedule, including mixed sizes on one board
• Rows × columns and center-to-center spacing from the drawing
• Flow, rebar, and ground-wire holes only where specified
• Repeating boards for long runs without forcing a catalog module

Molded chairs remain a valid product category for banks that fit their fixed grids. When the bank is custom, CNC HDPE sheet is the process that matches the print.

Plant and quality context

Hole arrays are cut on in-house 5-axis CNC equipment at 184 Commerce Center, Greenville, SC 29615. The quality system is certified to ISO 9001:2015. Boards ship to jobsites across the Southeast, with just-in-time and warehouse support when staging is part of the plan. Spacing along the run is typically every 4-7 ft per the civil package.

Full product detail, including the spec options table, lives on custom HDPE duct bank spacers. For data-center bank types (primary service, feeders, generator ties, fiber), see data center duct bank spacers.

How HDPE spacers are used on site

The boards hold and space conduits in underground concrete-encased duct banks for power, telecom, and data centers. Crews often prefabricate the array outside the trench, then lower it before the pour. Spacing along the run is typically every 4-7 ft. The spacer remains in the bank for the life of the installation.

Spec options that travel with the material choice:

• Rows × columns from the conduit schedule
• Hole OD matched to each conduit
• Center-to-center spacing from the print
• Optional flow, rebar, and ground-wire holes
• Typical thickness 3/8 in or 1/2 in HDPE sheet

Power and telecom banks both use the same CNC-cut sheet approach. Data-center primary service, MV/HV feeders, generator ties, and fiber banks are common vertical examples. When power and fiber share a sheet, the engineer specifies spacing; BRT cuts it and does not assign an EMI clearance.

Southeast fabrication and shipping

CNC routing happens at 184 Commerce Center, Greenville, SC 29615. Boards ship to jobsites across the Southeast, including the South Carolina, North Carolina, Georgia, Tennessee, and Virginia data-center corridor. Just-in-time shipping and offsite warehousing support staged deliveries when pours are sequenced across pads or buildings. The quality system is certified to ISO 9001:2015.

FAQ

Is HDPE the only material you cut for spacers?

The Wave-1 product line for duct bank spacers is CNC-routed HDPE sheet. If a drawing calls for another sheet material, ask; do not assume a substitution without a conversation.

Does “non-conductive” mean BRT designs the electrical clearances?

No. We fabricate the spacer geometry from your drawing. Clearances and EMI decisions belong with the design team.

Are HDPE spacers thermoformed?

No. They are CNC-routed from sheet. Thermoforming at BRT is a separate process for covers, housings, trays, and panels.

Custom HDPE duct bank spacers