Skip to content
Nomaco Closed Cell Backer Rod, 4 in. Diameter x 6 ft. Construction Foam
Regular price $16.25Orders start at $399 — combine any items to reach the minimum. Learn more
Nomaco Closed Cell Backer Rod, 4 in. Diameter x 6 ft. Construction Foam
This Nomaco closed cell backer rod is a 4 in. diameter, 6 ft. long construction foam filler for concrete expansion and contraction joints. Engineered for commercial, residential, municipal, civil, and industrial projects, it backs up sealant joints in nearly any concrete structure. One piece per order.
Key Features:
- Closed cell foam: Closed cell construction foam serves as a filler for concrete expansion and contraction joints.
- Large diameter: 4 in. diameter rod sized for wide horizontal and vertical joints.
- 6 ft. length: Each piece measures 6 ft. long.
- Multi-market use: Designed for commercial, residential, municipal, civil, and industrial projects.
- Versatile filler: Can also be used as a concrete form almost anywhere concrete is used.
Specifications Table:
| Specification | Details |
|---|---|
| Brand | Nomaco |
| Sell unit | 1 piece, 4 in. x 6 ft. |
| Product line | Nomaco construction foam materials |
| Material | Closed cell foam |
| Nominal size | 4 in. x 6 ft. |
| Diameter | 4 in. |
| Length | 6 ft. |
| Intended use | Filler for concrete expansion and contraction joints; concrete forms |
| Applications | Commercial, residential, municipal, civil, and industrial projects |
Coverage & How Much You Need:
One 6 ft. piece fills 6 linear feet of 4 in. wide joint when sized per standard practice at roughly 25% joint-width compression. Order pieces by dividing total joint length by 6 ft. and allowing for splices.
Fit and Compatibility:
Use behind compatible joint sealants in concrete expansion and contraction joints. Diameter should be oversized roughly 25% relative to joint width for proper compression fit.
Frequently Asked Questions (FAQ):
Q: What is included in one order?
A: One 6 ft. piece of 4 in. diameter closed cell backer rod.
Q: How much joint does one piece fill?
A: One piece covers 6 linear feet of joint at 4 in. diameter; order by total joint length with allowance for splices.
Q: Where is this rod used?
A: It fills concrete expansion and contraction joints and can serve as a concrete form in commercial, residential, municipal, civil, and industrial work.
Q: Why closed cell?
A: Closed cell foam resists absorbing moisture and gases, which helps control sealant bubbling in horizontal joints.
Q: What size joint does this fit?
A: Backer rod is typically installed compressed about 25%, so a 4 in. rod suits roughly a 3 in. wide joint; confirm with your sealant spec.
Expert Verdict — Reviewed by the SuperArbor Pro Desk
On wide expansion joints, correct backer rod diameter is as important as the sealant itself: undersized rod lets the sealant sink and tear, while oversize rod is difficult to seat. This 4 in. closed cell rod suits large civil and industrial joints. Insert it with a roller to reach the specified depth before tooling the sealant.
Follow sealant manufacturer safety guidance and wear gloves and eye protection when cutting and installing backer rod.
Get the Nomaco closed cell backer rod sized right for your expansion joints.
All third party trademarks, including logos and icons, referenced on our website and product pages remain the property of their respective owners. Unless specifically identified as such, Arbor's use of third party trademarks does not indicate any relationship, affiliation, sponsorship, or endorsement between Arbor Home and the owners of these trademarks. Any references by Arbor Home to third party trademarks are to identify the corresponding third party goods.
