---
product_id: 179540496
title: "1\" Closed Cell Backer Rod/Crack Filler (25 ft)"
brand: "armacell"
price: "A$43"
currency: AUD
in_stock: true
reviews_count: 8
category: "Armacell"
url: https://www.desertcart.com.au/products/179540496-1-closed-cell-backer-rod-crack-filler-25-ft
store_origin: AU
region: Australia
---

# Waterproof closed-cell foam 1" max gap fill 25 ft length for large projects 1" Closed Cell Backer Rod/Crack Filler (25 ft)

**Brand:** armacell
**Price:** A$43
**Availability:** ✅ In Stock

## Summary

> 🛠️ Seal smart, save more—don’t let gaps steal your comfort!

## Quick Answers

- **What is this?** 1" Closed Cell Backer Rod/Crack Filler (25 ft) by armacell
- **How much does it cost?** A$43 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.com.au](https://www.desertcart.com.au/products/179540496-1-closed-cell-backer-rod-crack-filler-25-ft)

## Best For

- armacell enthusiasts

## Why This Product

- Trusted armacell brand quality
- Free international shipping included
- Worldwide delivery with tracking
- 15-day hassle-free returns

## Key Features

- • **Caulk Saver:** Prevents caulk from ripping loose, extending sealant life
- • **Extended Reach:** 25-foot length covers big projects without interruption
- • **Perfect Gap Filler:** Seals gaps from 3/4" to 1-1/8" with precision
- • **Durable & Waterproof:** Closed-cell foam resists water and weather damage
- • **Versatile Application:** Ideal for floors, garage seals, and metal panel joints

## Overview

Armacell 1" Closed Cell Backer Rod is a durable, waterproof foam rod designed to fill and seal large gaps from 3/4" to 1-1/8" wide. Sold in convenient 25-foot lengths, it supports caulk application by preventing ripping and enhancing insulation, making it perfect for floors, garage seals, and metal panel joints.

## Description

Backer rod is important when sealing large gaps. It allows caulk to span a gap without ripping loose. In the example above backer rod is used where the radon pipe enters the floor before caulk is applied. 1" backer rod is perfect for filling gaps 3/4" to 1-1/8" wide. Sold in 25 foot lengths.

Review: Great insulation or garage seal. - Bought this to insert into our garage door bottom rubber seal and it fitted/worked perfectly for additional cushioning and insulation.
Review: Great Product to Use to Seal Gaps and Cracks - Great product. Have been using this to seal between walls and roof panels on metal shop. Use the backer rod in the gap along with foam gap and crack sealer (red stuff) and it seals perfectly. Afterwards we have applied closed cell spray foam over it and it dries hard making a perfect seal to ensure there is no transfer of heat, water or air. Good product, highly recommend.

## Features

- Fill large cracks
- Save caulk
- Keep caulk from ripping loose
- Fill large s

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B081NTJ51G |
| Best Sellers Rank | #64,035 in Tools & Home Improvement ( See Top 100 in Tools & Home Improvement ) #181 in Hardware Sealers |
| Brand | Armacell |
| Brand Name | Armacell |
| Color | Grey |
| Customer Reviews | 4.6 out of 5 stars 1,382 Reviews |
| Item Form | Foam |
| Manufacturer | armacell |
| Material Type | Rubber |
| Maximum Gap Fill | 1.13 Inches |
| Surface Recommendation | Floor |
| UPC | 301635340128 |
| Unit Count | 25 Feet |
| Water Resistance Level | Waterproof |

## Product Details

- **Brand:** Armacell
- **Color:** Grey
- **Item Form:** Foam
- **Maximum Gap Fill:** 1.13 Inches
- **Surface Recommendation:** Floor

## Images

![1" Closed Cell Backer Rod/Crack Filler (25 ft) - Image 1](https://m.media-amazon.com/images/I/41wpFNfbCWL.jpg)

## Questions & Answers

**Q: Pulled out my rotted 1x4 expansion wood and will have 1-2" void under backer rod when installed.  Any requirement to put something like sand under it?**
A: i think sand would work. Maybe backer rod under backer rod ?

**Q: Can this rod be easily compressed to fit into narrow spaces?**
A: Yes, it is foam and can be compressed by more than half, it can also be trimmed with scissors if needed.

**Q: Can this be used as concrete joint filler?**
A: Yes this works well to fill a gap in concrete, but it should be topped off a good caulk approved for use with cement.

**Q: it is stiff enough to force into the void in the garage door bottom seal?  I just replaced the seal and was looking for something to help keep shape**
A: I actually have some of this 1" backer rod slipped into the seal on my door to fix a section that separated. But it might be kind of difficult to pull into many feet of seal.

## Customer Reviews

### ⭐⭐⭐⭐⭐ Great insulation or garage seal.
*by S***A on December 29, 2025*

Bought this to insert into our garage door bottom rubber seal and it fitted/worked perfectly for additional cushioning and insulation.

### ⭐⭐⭐⭐⭐ Great Product to Use to Seal Gaps and Cracks
*by R***Y on October 22, 2025*

Great product. Have been using this to seal between walls and roof panels on metal shop. Use the backer rod in the gap along with foam gap and crack sealer (red stuff) and it seals perfectly. Afterwards we have applied closed cell spray foam over it and it dries hard making a perfect seal to ensure there is no transfer of heat, water or air. Good product, highly recommend.

### ⭐⭐⭐⭐ Not as advertised. 5’ short
*by R***T on May 29, 2025*

I ordered this product because the 1” size was what I wanted for a project I was working on. I also ordered from this seller because they said it was sold in 25’ lengths. I needed about 22’ continuous for my project and other sellers listed 10’ and 20’ lengths so I ordered this product. When I got almost thru the project I found there was only 20’ otherwise it was just what I wanted.

## Frequently Bought Together

- Armacell 1" Closed Cell Backer Rod/Crack Filler (25 ft)
- M-D Building Products - Versatile Gray Foam Backer Rod Set 1/2in x 20ft - Essential Caulk Saver for Sealing Concrete Gaps, Expansion Joints, and Crack Filling (71480)
- Sikaflex Self Leveling Sealant, Gray, polyurethane with an accelerated curing capacity for sealing horizontal expansion joints in concrete, 10.1 fl. oz Cartridge

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**Shop now:** [https://www.desertcart.com.au/products/179540496-1-closed-cell-backer-rod-crack-filler-25-ft](https://www.desertcart.com.au/products/179540496-1-closed-cell-backer-rod-crack-filler-25-ft)

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*Product available on Desertcart Australia*
*Store origin: AU*
*Last updated: 2026-03-01*