








🛠️ Seal smarter, save bigger—your go-to gap-filler for flawless finishes!
The M-D Building Products Versatile Gray Foam Backer Rod offers 350 feet of durable, weather-resistant foam designed to fill and seal medium-sized concrete gaps and expansion joints. Its flexible, easily trimmed design ensures a perfect fit for indoor and outdoor applications, providing a reliable base for caulking that enhances insulation, blocks drafts, and protects against moisture—all with quick, mess-free installation.





| Manufacturer | MD Building |
| Part Number | 71550 |
| Item Weight | 1 pounds |
| Product Dimensions | 10 x 11 x 12 inches |
| Item model number | MD Building - 71550 |
| Size | 350 Ft. |
| Color | Gray |
| Style | Backer Rod |
| Material | Foam |
| Pattern | Solid |
| Shape | Round |
| Item Package Quantity | 1 |
| Number Of Pieces | 1 |
| Included Components | MD Building - 71550 |
| Batteries Included? | No |
| Batteries Required? | No |
| Warranty Description | Warranty |
K**.
Good product
Works well. I bought it to fill in gaps in my driveway. For the smaller cracks I cut the width of it. It is durable and a good price.
K**N
Very fast shipping, and was exactly as ordered.
Great product, made sealing our driveway a breeze!
A**Y
Perfect for diy floor installation
We used this when installing engineered hardwood in our home. Functional, easy to use, and a great value. Would recommend!
W**M
bill
nice
J**L
This rod has my back!
Does what any good backer rod would! Works great and gets the job done.
J**E
nic backer rod
A good filler for wider spaces between two panels that saves caullk/ adnesive/ sealiant. I am using this backer in some spaces between sheetrock and flooring to liquid proof them. Also good to keep critters out.
B**E
Great for threshold gaps
Had a small gap in my front door threshold after one of our animals ripped up the material that was originally in the gap.After reading many reviews for this product, gave it a shot. It was just what I needed! Super easy to use: measure, cut, install. Fits perfectly in the gap. No need to worry about dirt, bugs, and other debris getting in the gap.Great value too, as the 20ft bag was only about $3.00, with plenty left over if I need to replace it again.Highly recommend.
L**A
Used in the bathroom and worked well
I cut these in half to make a half circle and then inserted them in between the drywall and subfloor to create a water tight seal along with caulking. I found that using the whole rod was too much and would prevent the baseboards from being installed flush with the flooring. I ended up returning half of them because I was able to cut the rod in half. Worked well and excellent.
Trustpilot
3 weeks ago
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