What to Put Under an Above-Ground Pool: Sand, Pads and Ground Prep for Every Shape and Size

Every page that ranks for this question gives you one answer, usually “two inches of sand and a pad.” It is the right answer for some pools and a warranty problem for others. We read the installation manuals of ten pool makers, and the first thing they disagree on is whether there should be any sand at all. The wall decides it.

First, which wall do you have

Not sure which you have? A frame pool hangs a soft liner from a tube frame; a steel or resin wall pool has a rigid wall rolled out on a track. Above-ground pool types has the full breakdown.

What every manual says, side by side

No single number is right across brands, and a few of the makers contradict each other. This is what each manual we read actually says.

Three things stand out. The “1 to 2 inch” tolerance credited to Intex is not in Intex’s manuals: only Doughboy and Wilbar put a number on level, and theirs is 1 in. None of the manuals we read mentions play sand, for or against; the steel-wall makers name masonry, brick or compaction sand. And the same document changed its own numbers: manual 95-0443 asked for a 2 in base and a 6–8 in cove in its 2016 edition, and a 3 in base and a 4 in cove in its 12/2022 edition. Aquarian is the one maker that lets you dig the middle out: up to 6 in at the centre for a standard liner, a dished floor. Your manual wins over this table, and over any calculator.

Prepare the ground: the same five steps for every pool

1. Pick the spot. Firm, undisturbed ground, out from under trees and power lines, with somewhere for the water to go if the pool ever lets go. Bestway’s round frame manuals say “at least 20ft. away from your home”; Intex wants 4 ft of clear space around the pool from anything a child could climb.
2. Strip the sod. Bestway “recommend[s] removing all grass” because it “will die and may cause odors and slime”; Wilbar says it “will rot underneath the pool liner”. Intex only says grass under the pool “will be damaged”, but it also says grass that grows through the liner is not covered. Take it up.
3. Level by digging, not filling. Find the lowest spot and bring everything else down to it. Doughboy: “Always remove dirt to adjust framework - never fill in!” Fresh fill compresses under the water, and the wall goes down with it. Where you must fill a small hollow, Wilbar says the soil “must be hard-packed with a tamping tool”.
4. Check it with a level, not your eye. A long straight board and a level, or a string line, across the whole footprint in several directions. For a frame pool, Intex’s own test: fill with no more than 1 in of water, and if it runs to one side, drain it and level again.
5. Tamp it. Every manual asks for compacted, firm ground: Intex says the surface “must be compacted and firm enough to withstand the pressure and weight of a fully set up pool.” Wilbar’s sand floor is wetted and packed with a lawn roller, then smoothed with a trowel.

Under the legs and uprights

This is where a frame pool sinks first. The rule in every manual that mentions it is the same: a solid, flat support, sunk until its top is flush with the ground, level with all the others.

• Intex rectangular frame pools (the Ultra XTR manual): on asphalt, lawn or earth, “pressure-treated wood, size 15” x 15” x 1.2” … under each U-shaped support and set flush or even with the ground”, or steel pads or reinforced concrete slabs. No smooth or slippery pads: the support slides outward and that voids the warranty. On concrete, none needed.
• Steel and resin wall pools: a patio block under every upright. Reprieve: “All patio blocks must be flush with the ground, solid and level with each other in all directions,” and “Do not install blocks or rails on loose sifted soil or sand.” Solid blocks, not hollow ones.

Sand: who wants it, who forbids it

Frame and Easy Set pools: no sand. Intex, Bestway’s manual and Polygroup all say so, and Polygroup says why: sand “will only wash out.” A frame pool’s liner sits on whatever is under it; sand migrates out from under the legs and the edges, and the floor goes lumpy. Bestway’s blog is the one dissent, allowing “no more than one or two inches” of mason sand as a liner buffer and never for levelling. If you follow the blog, you are following a softer rule than Bestway’s own warranty document.

Steel and resin wall pools: a sand floor, usually 2 in. It protects the liner from the ground and gives you a surface you can smooth with a trowel. Wilbar wants “fine brick sand (no pebbles)”, Radiant “clean washed masonry sand”, Cornelius “compaction sand”, Aquarian “compacting sand”, Hampton “fine (shell free) sand”. Wet it, roll or tamp it, and trowel it smooth. Doughboy is the exception: sifted earth for the floor.

The cove

The cove is a sloped fillet at the foot of the wall, inside the pool. Without it the liner is pressed into the right angle between the floor and the wall, stretches, and can creep under the wall. Reprieve: it “will prevent the liner from creeping under the wall.”

You can build it from sand (Wilbar: “6” (15.24cm) high and 6” (15.24cm) wide at ground level”), buy pre-formed foam strips that peel and stick to the wall, or, on a Doughboy, use screened damp earth or a pre-formed cove. Doughboy forbids sand here: “DO NOT USE MATERIALS THAT SHIFT IN COVE (LIKE SAND) OR POOL MAY EVENTUALLY RUPTURE.”

Foam strips do not wash out, which is the reason to pay for them. Two warnings from the listings we read:

• The pack labels run short. The count you need is your wall length divided by the strip length. Blue Wave’s 19-strip pack is sold for a 24 ft round, which takes 19 strips of 48 in with no slack at all, and three owners of it finished a strip short. The same listing says 19 covers a 16 × 32 ft oval, whose wall is about 82 ft and takes 21. Buy one more than the count.
• Strip lengths differ. Blue Wave, Aqua Select and Liner Armor sell 48 in strips; SmartLine’s are 46 in, and one owner of the NL104 pack measured its “48 in” strips at 46. A 46 in strip changes the count.
• A foam strip is lower than the sand cove it replaces. Blue Wave’s listing gives about 3 in of height, Aqua Select’s 2⅝ in, while the manuals’ sand coves run 4 to 8 in. Aquarian, Doughboy and the 12/2022 edition of manual 95-0443 all accept a pre-formed cove; check that yours does before you skip the sand.
• The adhesive is weak on every brand we read. Owners hold the strips with duct tape until the water is in, which then holds the cove in place. Stick them on the day the liner goes in.

Run your numbers

By pool size, round, oval and rectangle

Every row comes from the calculator’s own arithmetic: the floor is 2 in of sand, the cove column adds a 6 × 6 in sand cove, and strips are 48 in foam strips with no spare. A rectangle here is a steel-wall rectangle; a rectangular frame pool takes no sand and only needs the pad sized to its footprint.

The one maker’s sand table we found, against the arithmetic

Hampton is the only manual that prints a sand quantity, and from 18 ft up it is short of a 2 in floor before any sand goes into the cove. Spread evenly, its figure makes a floor of about an inch and a half. Order from the arithmetic, not the box.

SmartLine’s strip table, against the arithmetic

SmartLine’s own “how much do I need” table, at its 46 in strip, matches the stadium arithmetic on 17 of 18 rows. On the 30 ft round it asks for one strip more, which is the spare we would buy anyway.

Pool pads and ground cloths: what they do and do not do

A pad is a barrier, not a cushion. The pre-cut pads sold for above-ground pools are fabric, most of them described as non-woven geotextile, about a tenth of an inch thick by their listings. They stop the liner rubbing on grit and small sharp objects and keep it off the ground. They do not hide a lumpy floor, and on every pad we read the leading complaint was the same: owners expected padding and got felt. A heavier fabric weight does not change that. The newer pads sell on grams per square metre (220, 300, 350, 400 g/m²), and the critical reviews on the 300 and 400 g/m² pads say the same thing as the 220s; one owner of a “400 g/m² extra thick” pad wrote, “It would be nice if they would list a thickness rather than a density. It is only roughly 1/16” thick.” No pad maker we read publishes a thickness or a puncture rating, so buy on size coverage and seller, not on the density figure.

No pad stops nut grass. The maker of the Gorilla pad excludes it from its own 90-day warranty in writing, and grass coming through the pad is a recurring complaint on the others. Clear the grass before the pool goes up; a pad does not do it for you.

Where it goes. On a steel- or resin-wall pool, over the sand and under the liner (GLI describes its Armor Shield as the layer “between a vinyl swimming pool liner and it’s sand or soil base”). On a frame pool, on the cleared, level ground with the pool on top. Several of the pads we read are one rating pooled across every size they sell, so a pad’s stars describe the family, not your cut.

Ground cloths are thinner still: the Intex 28048E cloth we read is a thin sheet its owners call a tarp, and several say it tore or arrived with holes. Intex’s European support site says to “always place the pool on a mat. Most pools have the mat included. If not, you can place any fabric sheet under the pool.” When we read the Intex 28048E listing on 4 October 2026, its buy box was a used, no-retail-box offer, with new offers behind it under “Other sellers”.

The pad we pick sells every shape on one listing, so there is a card for each: the round links the 24 ft cut, the oval the 15 × 30 ft and the rectangle the 12 × 24 ft. Pick your own size from the listing’s menu; the rating is one pooled base across all 30 cuts.

Foam floor tiles exist, but the interlocking tiles that show up for “pool floor protector” are almost all shower and drainage tiles. The one purpose-built pool tile we found had 26 ratings, too thin a base to recommend.

Hard surfaces: concrete, pavers, asphalt, decks, turf

• Concrete: Intex’s rectangular manual treats it as the one ground needing no support pads, and Bestway’s Latin American manual lists it among suggested surfaces. Hampton says concrete will invalidate the liner warranty, and Doughboy lists it among surfaces to avoid while allowing an optional concrete footing under the pool with the cove still installed. Check your own manual.
• Pavers: Intex’s European support site says “Only lay the pool on a hard surface such as garden pavers”; a paver patio still has to be level and flat across its joints, and the liner still wants a pad or cloth over it.
• Asphalt: Intex’s rectangular frames allow it with the 15 × 15 in boards; Bestway, Polygroup and Hampton forbid it.
• Decks, balconies and platforms: Intex, Bestway, Polygroup, Doughboy and Wilbar all forbid them. A filled pool weighs tons.
• Artificial turf: no manual we read addresses it. It is not compacted ground, and nothing we read supports putting a pool on it.

Weeds, roots and chemicals

Clear aggressive grasses first: Intex and Polygroup name St. Augustine and Bermuda, and Wilbar and Reprieve name nut grass. Hampton warns “Do not use any oil based weed killer on cleared ground as it could stain the liner.” Reprieve warns against peat moss and anything highly alkaline or acidic under a steel wall because “IT WILL CORRODE METAL PARTS!”, and suggests plastic sheeting under the cove so no treated earth touches the wall. Doughboy warns off soil that has “recently undergone petroleum based chemical treatments.” Aquarian’s manual goes furthest: “Spread area with salt in order to prevent roots from growing back and to eliminate earthworms,” then ant repellent, both named as causes of cracking. No manual we read endorses a specific weed killer; Wilbar’s says to ask your dealer what works on nut grass locally.

The one-line version

Frame pool: no sand, dug-level compacted ground, a cloth or pad, and flush boards under any U-supports. Steel or resin wall: dug-level ground, flush solid blocks under every upright, the sand floor and cove your manual specifies, and a pad over the sand if you want one. Then open it and pick a pump.