Duct Spacers · Size 4 inch (100 mm)
4" Duct Spacers (100 mm)
A 4" duct spacer holds 4" (100 mm) conduit — the workhorse size for electrical power and HDPE fiber duct banks — in precise horizontal and vertical alignment through the pour and backfill.
The 4" size is the most-specified duct spacer on power distribution and fiber/BEAD builds, where 4" PVC and 4" HDPE conduit carry the bulk of the run. Innovative Plastics offers 4" base and intermediate spacers in high-impact polymer with the same no-banding interlock as the rest of the line.
Four separations are available at 4" — 1", 1.5", 2", and 3" — so you can tighten or open the grid to the gap your engineer specified. The 4040 (base) and 4140 (intermediate) part numbers below cover every combination.
These spacers suit both encased-burial (concrete-pour) and direct-burial banks, and hold alignment against concrete float when the assembly is staked or tied as a unit. See the full duct spacers range for other sizes, or our guide to duct bank spacing.
Specifications
4 inch (100 mm) sizes & part numbers
Price: $1.23–$1.55 each, effective 2026-07-23. Minimum order one case; volume & distributor pricing available.
| Product image | Product Number | Trade Size (in) | Trade Size (mm) | Case Qty | Price (USD) | Order (cases) |
|---|---|---|---|---|---|---|
 | 4040-10 | 4.00 x 1.00 | 100 x 25 | 250 | $1.31 | |
 | 4040-15 | 4.00 x 1.50 | 100 x 40 | 180 | $1.37 | |
 | 4040-20 | 4.00 x 2.00 | 100 x 50 | 180 | $1.38 | |
 | 4040-30 | 4.00 x 3.00 | 100 x 80 | 150 | $1.55 | |
| Product image | Product Number | Trade Size (in) | Trade Size (mm) | Case Qty | Price (USD) | Order (cases) |
|---|---|---|---|---|---|---|
 | 4140-10 | 4.00 x 1.00 | 100 x 25 | 250 | $1.24 | |
 | 4140-15 | 4.00 x 1.50 | 100 x 40 | 180 | $1.23 | |
 | 4140-20 | 4.00 x 2.00 | 100 x 50 | 160 | $1.31 | |
 | 4140-30 | 4.00 x 3.00 | 100 x 80 | 125 | $1.48 | |
Made in Texas, USA · ships across the US. Looking for other sizes? See the full Base & Intermediate range.
FAQ
Frequently asked questions
- Do 4" duct spacers work with HDPE conduit?
- Yes. The 4" spacers cradle 4" conduit whether it is rigid PVC or HDPE, which makes them a common choice on fiber and BEAD duct banks that use 4" HDPE duct.
- What separations are available at 4"?
- Four separations — 1" (25 mm), 1.5" (40 mm), 2" (50 mm), and 3" (80 mm) — in both base (4040) and intermediate (4140) styles.
- Are 4" duct spacers rated for concrete-encased duct banks?
- Yes. They are used in both encased-burial and direct-burial installations; the interlocking grid can be staked or tied down so it holds alignment against concrete float during the pour.
Full product family
This page covers the 4 inch (100 mm) size. See every size, spec, and part number on the Base & Intermediate page or browse the full Duct Spacers range.
Guides & resources
- Conduit Duct Bank Spacing: Intervals, Separation, and Cover How to space conduit in a duct bank — spacer intervals along the run, separation between conduits, and concrete cover for encased and direct-burial installations.
- How to Install Conduit Duct Spacers A step-by-step guide to assembling base and intermediate conduit duct spacers into an aligned duct bank for encased or direct-burial installation — no banding required.