Nomaflex expansion joint filler and backer rod
Nomaflex is Nomaco's closed-cell polypropylene foam expansion joint filler for concrete, made to ASTM D8139. It is set against a fixed edge before a pour so slabs, walks and curbs can move without cracking. Yankocy stocks Nomaflex wholesale in 10 ft lengths, 1/2"x4", 1/2"x6" and 3/4"x6", with foam joint, zip strip, void cap and Ethafoam backer rod.
Nomaflex expansion joint: what we stock
| Product | Sizes and options |
|---|---|
| Nomaflex, 10 ft | 1/2"x4", 1/2"x6" and 3/4"x6" |
| Foam expansion joint | 4"x50', 6"x50' |
| Zip strip | 1"x10', 1.5"x10' |
| Void cap | 1/2"x10' |
| Backer rod (Ethafoam) | 1/4" 4,000'/carton; 3/8" 2,100'/carton; 1/2" 2,500'/carton |
What is Nomaflex?
Nomaflex is a semi-rigid, closed-cell polypropylene foam plank. It does not soak up water, swell, rot or flake, so it can be stored outside and passed across a wet pour without breaking. Nomaco lists it as fully compliant with ASTM D8139, and with ASTM D1751 for extrusion, compression recovery and water absorption tested per ASTM D545.
It works with hot-pour and cold-applied sealants and prevents three-sided sealant adhesion, so no separate bond breaker is needed. Set it 1/2" below the finished surface when a plastic edge cap will go on top. Nomaco packs 10 ft plank in bundles of 10.
| Property (Nomaco data sheet) | Value |
|---|---|
| Water absorption | Less than 1% |
| Compression strength | More than 30 psi, less than 60 psi |
| Compression recovery | More than 80% |
| Extrusion | Less than 0.1 in. |
| Freeze-thaw, 300 cycles | No change |
| Density | More than 3.5 lb/cu ft |
Which joint product for which job
| Product | Sizes Yankocy stocks | Used for |
|---|---|---|
| Nomaflex plank | 1/2"x4", 1/2"x6", 3/4"x6", 10 ft | Isolation and expansion joints at walls, curbs, foundations and slab edges |
| Foam joint roll | 4" and 6" x 50' | Long continuous runs where a roll is faster than plank |
| Zip strip | 1" and 1.5" x 10' | Plastic strip set in fresh concrete to form a joint line |
| Void cap | 1/2" x 10' | Plastic cap over joint filler, pulled after the pour to leave a sealant pocket |
| Ethafoam backer rod | 1/4", 3/8", 1/2" | Sets sealant depth in joints that are sealed after the pour |
Backer rod sizing
Backer rod goes into the joint before the sealant to control bead depth and stop the sealant bonding to the bottom of the joint. Nomaco's guidance for its closed-cell rod is to oversize the rod 25 to 50 percent over the joint width so it stays put under compression. Its chart pairs rod and joint sizes like this:
| Rod diameter | Joint width (Nomaco chart) | Yankocy carton |
|---|---|---|
| 1/4" | 3/16" or less | 4,000' |
| 3/8" | 1/4" | 2,100' |
| 1/2" | 3/8" | 2,500' |
Confirm rod compatibility and bead depth with the sealant manufacturer.
Questions about Nomaflex expansion joint
What is Nomaflex?
Nomaflex is an expansion joint filler made by Nomaco from semi-rigid, closed-cell polypropylene foam. It is placed at concrete edges and between slabs so the concrete can expand and contract. It does not absorb water or flake, and Nomaco lists it as compliant with ASTM D8139 and D1751.
What do you fill expansion joints with?
A preformed filler such as Nomaflex or foam joint goes in before the pour. Where the joint will be sealed, a void cap or pre-scored strip leaves room at the top for sealant, and backer rod sets sealant depth in joints sealed later. Yankocy stocks all of these wholesale.
What size backer rod do I need?
Pick a rod 25 to 50 percent wider than the joint so it compresses into place, per Nomaco's guidance. Its chart uses 1/4" rod for joints 3/16" or less, 3/8" rod for 1/4" joints and 1/2" rod for 3/8" joints. Yankocy stocks Ethafoam backer rod in those three sizes by the carton.
What Nomaflex sizes does Yankocy stock?
Yankocy stocks Nomaflex in 10 ft lengths at 1/2"x4", 1/2"x6" and 3/4"x6", plus foam joint in 4" and 6" x 50' rolls, zip strip, void cap and backer rod. Nomaco makes other thicknesses and widths. Call (203) 261-4955 or email info@yankocy.com for sizes not listed.
Last updated
Yankocy sells Nomaflex and joint accessories wholesale to mason yards and municipalities. Buying for your own home? Your local lumber or mason yard can order it for you.
Nomaflex expansion joint data sheets and sources
- Nomaco Nomaflex product page
- Nomaco Nomaflex plank and sheet data sheet (PDF)
- Nomaco HBR closed-cell backer rod data sheet (PDF)
Related to Nomaflex expansion joint
Wholesale pricing on Nomaflex expansion joint
Tell us the products, sizes and quantities, and where the order is going. Inside sales will get back to you with pricing and availability.
- Delivery
- Weekdays on our own trucks to Connecticut, southeastern New York, northeastern New Jersey, Long Island, western Rhode Island and southern Massachusetts. Delivery area
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Prefer the phone? Call inside sales at (203) 261-4955.