Fence Post Anchor
FAST 2K™ FENCE POST BACKFILL
Install Posts Fast with Expanding Foam Fence Post Mix
Fast 2K™ Fence Post Backfill is a fast, mess-free solution for setting fence posts and more. This expanding foam fence post mix replaces up to 100 lbs. of concrete with a lightweight, easy-to-use composite that sets posts in minutes. Ideal for non-load-bearing applications like fences, mailboxes, or light posts, it simplifies the entire process and minimizes cleanup.
How It Works: A Cleaner Way to Set Posts
Now, within minutes, you can set fence posts, mailbox posts, decorative light posts, sports posts and much more.
It pours as a liquid and expands to fill the void between the soil and the post.
No water, no wheelbarrow, no messy mixing, or time consuming clean up. Fast 2KTM Fence Post Backfill is much faster and more convenient than concrete.
- For non-load bearing projects only
- Lightweight and convenient
- No water required
- Mix in 30 seconds / Set in 5 minutes / Build in 30 minutes
- Works with all post types (wood, metal, vinyl, plastic)
- Water-resistant when fully cured
- Can be used is below freezing temperatures
FENCE JOBS CAN BE BUILT 15-30 MINUTES AFTER POURING
WORKS IN WINTER
Acclimatize before using
Fast 2KTM sets posts fast after mixing, so be sure your posts are plumb. While you're doing that get your bags acclimatized by keeping them between 72°F – 77°F for 2 hours.
FINISHING YOUR PROJECT
Holds post in 2-5 minutes
Have your posts ready to go and plumb when you start mixing Fast 2KTM. In only 30 seconds you’ll need to cut and pour Fast 2KTM as it expands immediately after mixing and holds the post in 2-5 minutes.
USING FAST 2K™ SAFELY
No hazardous ingredients
After Fast 2KTM has been mixed and cured, the material inside the ground is chemically inert and non-hazardous.
NEED HELP PLANNING YOUR PROJECT?
Use our Post Foam Backfill Usage Calculator to determine how many kits you’ll need for your fence or mailbox install.
Want to see how it works? Our Post Foam Tutorial Videos show you exactly how to install Fast 2K™ like a pro — step by step.
If your project is load-bearing, check out our Post Anchor for added strength and code compliance.
Proven Performance with Foaming Fence Post Technology
Fast 2K™ Fence Post Backfill evolved from the same foaming technology used to set utility poles for over 20 years. Our foaming fence post solution is trusted in the field and optimized for residential use.
Available Packaging
- 32.8 fl oz (970 mL) – 10 kits/case
RECENT ARTICLES
REVIEWS – HERE’S WHAT OUR CUSTOMERS HAVE TO SAY
Fast 2K Fence Post Backfill is super lightweight and forms a waterproof barrier that extends the life of wooden posts. This foam is also strong enough to resist lateral force of more than 500 lbs. and has the compression strength three to four times that of tamped soil. And it doesn't need to be mixed with water. You just pull the clip that separates the two components, mix the bag for 30 seconds and pour the liquid down the hole. The post/pole will be ready for use in just 15 minutes!
The Family Handyman
I just wanted to reach out and say Thank You. I had seen your product on YouTube before I seen it at Menards. I wanted to try it as I thought that the foam may help absorb energy from impact. I used your post foam, a wood post, and a good solid steel mailbox. As of today, just a few months in, my mailbox has eaten it’s THIRD vehicle mirror and the combination is holding up much better than I assumed. The foam and the wood compliment each other excellently. Thank you and God Bless!
Joe S. Scottsburg, IN
We were impressed how easy and fast and the posts are sturdy and we absolutely are using it again for more projects . We loved the simplicity and fastness and the post held strong as cement ones we put in. Thank you and God Bless!
Ron K. - Two Rivers, WI
Last summer while I was away on business, we had a wicked wind storm in Airdrie, AB and it blew away part of our fence. I told [my neighbor] one morning that I will take care of replacing the fence post myself. By the time they got back from work, I already had all the posts up and was starting on the fence. I showed him the fast 2k product that I had used and was pretty surprised myself on the efficacy and strength of said product.
Oliver M. - Aridrie, Alberta
We were impressed how easy and fast and the posts are sturdy and we absolutely are using it again for more projects . We loved the simplicity and fastness and the post held strong as cement ones we put in. Thank you and God Bless!
Mike B. - Illinois
We recently built a privacy fence in our backyard and both my husband and myself were not looking forward to hauling a ton of concrete/wheelbarrowing it etc to the site of the project to set the posts. We came across a product at Lowes called Fast 2K which looked unbelievably easy. We were thrilled, this product was so easy to use and with the bonus of no clean up etc. A bonus when tackling home reno projects yourself.
Debbie W. - Barrie, ON
I love my concrete but this stuff is awesome. I had around 30 4×6 posts to set for a couple fences I was building around the Jump Caddy shops. So I made up some quick support to hold a post perfectly straight and level and poured in a bag. While I worked on the next post the first one had already set so I was able to just grab the same supports and move them with me. In the past I would have spent a long day getting all the posts set perfect and then an even longer time mixing cement and pouring all of the holes hoping that something didn’t shift.
Rod D. - Jump Caddy Equestrian and Custom Wagons
We have recently used Fast 2K to install two 45” wide signs and another one 68” wide with two posts each. We were impressed with how quick Fast 2K sets without the mess of concrete. The signs we did were replacements, so we had to remove the original signs first and the holes ended up being pretty wide. So we poured one bag of Fast 2K in one hole, then poured another bag in the second one, topped up the first one after a couple of minutes, topped up the second hole and so on. It was so much faster than using concrete that we finished the job in almost half the time.
Derrick M. - Island Woodworks Plus Plus
My son’s fence built in two and a half days. Everybody wants to know how it got built that fast, We did it with Fast 2K two part foam. Dug the holes and set the poles before lunch and after lunch started put 1X6 cedar on. Finished with building the gate on Sunday.
Doug Y. - Scott's Lumber