Sand vs Gravel Backfill...and even Dirt! Which is superior?

Rico Laguno

Active member
Aug 19, 2010
35
Nyack, NY
Im curious on everyone's thoughts about using one or the other for a backfill of either a fiberglass or vinyl lined pool. It seems that many installers use Sand to compact and backfill, while others swear by gravel or even 3/4, 3/8 QP stone and condemn sand.

And even many other pool builders just throw the dirt they removed back in as backfill.


Can any professionals shed light on the proper, most superior way to backfill either type of pool and explain why that was is the best?


Im a bit surprised there are this many standards out there with a process that is so critical to a pool and decking's foundation.
 

bk406

Well-known member
Dec 3, 2009
2,690
Central Massachusetts
I like to see stone put in after the concrete collar is poured. About 2 feet of stone around the pool with a french drain in the stone. On top of that, processed gravel works well up to the top of the pool, compacted in 8-12 inch lifts. That makes a good compacted base for pavers or concrete. Not a big fan of sand. I would never let them use what came out as backfill. You need good material for backfilling an over dug pool.
 

Rico Laguno

Active member
Aug 19, 2010
35
Nyack, NY
would any scenario support actually using the same dirt removed?....Such as builders that use deck support collars or braces attached to the A-Frames? Im not sure what they're called but they looked like evenly spaced beams extended out from the A Frame a few feet out around the entire perimeter of the pool to provide extra decking support.
 

bk406

Well-known member
Dec 3, 2009
2,690
Central Massachusetts
Rico Laguno said:
would any scenario support actually using the same dirt removed?.....
I wouldnt. It wont compact as well in a short period of time like processed material. Beside, good material only cost about $12 a yard. For a typical overdug pool the price for good backfill might only be $500 or so. When your spending thousands for an IG pool, why get cheap on the backfill when its pretty inexpensive in the grand scheme of things.
Just my opinion.
 

Rico Laguno

Active member
Aug 19, 2010
35
Nyack, NY
yeah, thats a good point...also, is there a expected amount of time to wait to put in a 3ft patio around the pool, or can it be done during the pool installation if gravel or clean stone is used?
 

bk406

Well-known member
Dec 3, 2009
2,690
Central Massachusetts
Some would say it's ok to do it right away, some say wait. All 4 guys I talked to that i gogt bids from said wait until the next spring. Over the winter, it will settle a little bit. Although if you use good bakfill material, the settling is minimal and by the time spring comes around, the base is nice and compacted for the deck. A long way to say, I would wait until spring if the pool goes in during the fall.
 

Malibu07

Well-known member
Jun 20, 2010
212
Southeast VA
bk406 said:
Some would say it's ok to do it right away, some say wait. All 4 guys I talked to that i gogt bids from said wait until the next spring. Over the winter, it will settle a little bit. Although if you use good bakfill material, the settling is minimal and by the time spring comes around, the base is nice and compacted for the deck. A long way to say, I would wait until spring if the pool goes in during the fall.

I'm in the process of compacting the backfill. They used sand, gravel and the dirt that came out of the ground for the fill. I have been spraying water around the perimeter of the pool to help it settle....of course Hurricane Earl helped some too!
My question is, if I wait until spring for the apron or cement deck, how would I secure a solid cover on the pool? I have an 87 lb. black lab and I want a cover that will be safe even for my dog.
 

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