Fiberglass pool install - without concrete collar?


Well-known member
May 24, 2018
NB, Canada
Hi everyone,

How important is a concrete collar around a fiberglass pool?

We have installed a 26x12.5 rectangular pool with average depth of 4.75 feet. My father-in-law and I hired the excavation and prepped the base. The setting went well and is dead-on level, backfill with gravel (spending a ton of time making sure under the fiberglass steps were fully filled and tight, etc.) up the plumbing holes for now.

This is my father-in-law's second fiberglass pool install - he had done it for my brother in law in 2011 with a 32x15 rectangular pool. He did not use a concrete collar on that one and it is still perfect to this day, 7 years later. The pool was coped with pavers, etc. and with aggregate surrounding the pool underneath the pavers, etc.

To be clear, my father-in-law is not a pool installer but ran a concrete foundation business for 30 years and is extremely knowledgeable on compaction, etc. Pools are only something he offered to do after a bit of research. He is the most thorough guy when it comes to this stuff and is the last guy to take shortcuts - he actually thinks the collar could create some issues with frost heave that could potentially bring up the pool and the surrounding pavers on top of the concrete. It's not that we are lazy to pour it, we are worried that it could make things worse...

Obviously being a concrete guy we can figure out the cantilevered collar if absolutely necessary but we are wondering if it's necessary since we had great results without it...

Would appreciate any opinions on this topic!




Mod Squad
LifeTime Supporter
Jan 17, 2012
Evans, Georgia
If we are speaking of the same thing-
I have seen many pool pictures here that did not use a collar. The pool's lip makes it sort of look like a bathtub.

Here is a frequent poster who changes his coping and deck area occasionally- New pool proj.Flagstoning around (and on) my fiberglass pool

The weight of the water holds the pool down so a cement collar around the pool isn't required, just nice looking, IMO.

Maddie :flower: