















🛠️ Seal Smart, Save Big — The Ultimate Caulk Sidekick!
The M-D Building Products Versatile Gray Foam Backer Rod is a 250-foot, 1/2-inch diameter foam rod engineered for sealing medium gaps in concrete, doors, windows, and expansion joints. With a tensile strength of 35 PSI and waterproof, weather-resistant construction, it ensures durable, airtight seals that reduce caulk usage and improve insulation. Easy to install and trim, this backer rod is a must-have for professional-grade weatherization and energy efficiency.










| ASIN | B00C1TGKZW |
| Batteries Included? | No |
| Batteries Required? | No |
| Best Sellers Rank | #673,929 in Tools & Home Improvement ( See Top 100 in Tools & Home Improvement ) #817 in Adhesive Caulk #1,334 in Industrial Sealants #144,830 in Hardware |
| Brand | M-D Building Products |
| Color | Gray |
| Customer Reviews | 4.4 4.4 out of 5 stars (80) |
| Date First Available | March 27, 2013 |
| Global Trade Identification Number | 00043374715514 |
| Included Components | MD Building - 71551 |
| Is Discontinued By Manufacturer | No |
| Item Form | Foam |
| Item Package Quantity | 1 |
| Item Weight | 0.01 ounces |
| Item model number | MD Building - 71551 |
| Manufacturer | M-D Building Products |
| Material | Aluminum |
| Maximum Gap Fill | 0.5 Inches |
| Measurement System | Inch |
| Mounting Type | Wall |
| Number Of Pieces | 1 |
| Number of Items | 1 |
| Part Number | 4962239 |
| Pattern | Solid |
| Product Dimensions | 13 x 10 x 10 inches |
| Shape | Round |
| Size | 250 Ft. |
| Style | 250 Ft |
| Surface Recommendation | Concrete, Door, Walls, Window |
| Tensile Strength | 35 Pounds Per Square Inch |
| UPC | 043374715514 |
| Unit Count | 1.0 Count |
| Water Resistance Level | Waterproof |
N**D
makes great insulation
closed in a screened deck and made a glassed in sunroom. Used backer rod to fill in the gaps between deck boards. I'm relatively sure the rod doesn't have a large R value, but it stopped the wind from blowing through the floor. It did make it possible to heat the room with a mini-split (which is not overloaded). It has kept the sunroom quite comfortable during winter (temps down to 8F). If it works as well in the summer heat, I'll give it high marks as an insulator.
L**A
Great as always
A must-have for any caulking or sealing job. Reduces the amount of product you need to waste by filling in the empty holes.
A**N
No more drafts
We used it in more areas than we thought we would. Perfect for all the little insulation projects!
C**S
Worked perfectly
Trustpilot
3 weeks ago
2 months ago