Pool Safety Cover Anchors and How to Install Them

How many anchors do you need? Count the straps

One anchor per strap, one spring per strap. That is the whole rule, and it means the number of anchors going into your deck was settled at the factory when the cover was sewn. Unroll the cover, count the straps, and you have your answer.

The internet says otherwise, quoting an anchor every 3 feet or a fixed count for a 20 x 40 ft pool. That specification does not exist. We read six manufacturers' installation manuals looking for a perimeter spacing and found none. What we found instead: Meyco's packing list allots one brass anchor and one compression spring to each strap, Merlin has the installer count springs against straps before a hole is drilled, and Latham's step 4 has you measure the gaps between your own cover's straps and copy them onto a chalk line.

One published spacing does exist, and it is not on the deck. Where a cover crosses a raised wall it hangs from a stainless cable, and the wall anchors holding that cable are spaced: GLI and Merlin both say roughly 18 in on a tight radius and 3 ft on a straight run. A cable has no straps to follow.

There is one more thing worth knowing, because it explains why your strap count is what it is. A safety cover is built out of square panels, and the straps run along the seams between them. Order a cover and the grid is part of the order: squares of about 5 ft for a rectangle, or about 3 ft where the edge curves. Kidneys, freeform pools and anything unusually large are built on the tighter grid, which is why two covers of the same area can carry very different numbers of straps. So the spacing was decided the day the cover was ordered, not the day it goes on. That is precisely why no installation manual states one, and why counting your own straps is the only answer that is right for your cover. If you are ordering rather than installing, the custom cover page covers the grid and what it does to the price.

The tools, and the wrench nobody agrees on

Latham's own list runs to six items: hammer drill, 3/4 in carbide masonry bit, tape and pencil, hammer, chalk line, construction vacuum. The full kit:

Check the hex key against your own anchor before you order one, because that size is not settled and the 1/4 in everybody repeats comes from the aftermarket keys rather than from any manufacturer. Our 1/4 in hex key is 9.5 in long and fits the brass anchors on this page.

Square the cover, then work out from the center

Every hole is permanent, so the marking is the job and the drilling is the easy part.

1. Get your overlap by arithmetic. Cover size minus pool size, halved. Ours are cut to the pool plus 2 ft, so 1 ft of fabric lands on the deck all round.
2. Chalk a center line at each end of the pool, 3 to 4 ft out onto the deck, then spread the cover from the shallow end, right side up, overlap even all round.
3. Find the setback by pulling. Slip a spring halfway onto each center strap, pull strap and spring taut, and mark where the spring ends.
4. Snap a line parallel to each wall between two points measured at that distance, then copy the strap gaps onto it, working outward from the center strap and alternating side to side. That line, not your eye, keeps the anchors straight.

Attachment follows the same outward pattern: both ends before either side, side springs next, step springs last, corners last of all. A corner anchor may need a slight angle to pull the fabric flat, and Anchor Industries wants it more than 1 in clear of a 90 degree corner. Cutouts outrank the center rule and go first. GLI puts the mistake in capitals: never anchor one end and walk the cover to the far end, because the straps stop meeting the anchors and the overlap runs out on one side. Corners first is a published method rather than an error, though: Loop-Loc sets the eight corner anchors before anything else, and Meyco offers the same as an alternative for rectangles.

How far back from the pool the anchors go

About 30 in, derived rather than trusted. Latham gives 30 in as the usual distance from the pool edge and shows its arithmetic: the cover reaches roughly 12 to 18 in onto the deck, and the springs and strapping take another 18 in beyond that.

Published figures scatter across half a foot because each manufacturer measures from somewhere different. GLI uses overlap plus 22 in, so a 12 in overlap puts the anchor 34 in from the water and an 18 in overlap 40 in. Meyco and Merlin both work 20 in back from the cover's edge, landing at 32 to 38 in and 32 to 33 in from the water. Anchor Industries works off the cover too, at roughly 1 ft 5 in. Four of those five measure from the cover rather than the pool, which tells you what the distance really is: a fixed allowance for one spring and one strap. Reproduce it on your own deck, and if you must err, err outward. Latham names the failure mode for an anchor set too close: no room to tension the spring in both directions, so the cover sags and stops draining.

Drilling and setting a brass anchor

The hole is 3/4 in across, printed by Latham, GLI, Meyco, Merlin and Anchor Industries alike, which makes it the most settled number in the job. Depth is the opposite, and Latham's instruction is the one to follow because it is right for every anchor: set the depth off the anchor in your hand. Tape the bit at the length of the anchor body, drill to the tape, then drop the tamping tool in upside down. Its shoulder should finish just under deck level.

1. Vacuum the hole. Enough dust in the bottom and the anchor never goes fully home.
2. Take the screw out of the casing and spray casing, insert and tool with silicone. Oil and grease do not belong on brass.
3. Set the body first. Stand the casing over the hole, put the tool inside it, tap gently until the body is level with the concrete. The body finishes flush, always.
4. Thread the lubricated insert in afterwards, stopping while the smooth part still stands proud. GLI describes roughly a third of the insert showing, Anchor Industries and Merlin about 1/2 in.

Our brass anchor for concrete decks is brass because it spends its life in wet concrete, and it is a different part from the wood deck version. A chipped hole is hidden by a brass trim collar. Merlin sets a floor on the slab itself, 3 to 4 in of concrete for an anchor to hold.

Four numbers the manufacturers do not agree on

None of these are rounding differences. Each is a manufacturer's own published tolerance, and the manual in your box governs your warranty.

Fitting the springs, and how tight is tight

The spring goes on with the rod, and with your foot rather than your hand. Slide it a few inches onto the installation tool, hook the heel behind the raised anchor, swing the handle away from the pool to lever the spring over the anchor head, and step down. Half a turn frees the rod. Latham voids the warranty if springs are fitted or released without it.

Tension goes wrong in both directions. Too slack and the cover whips in wind and abrades on the coping, wear Meyco excludes from its warranty. Too tight and load goes into fabric and coping unevenly. What no manual we read claims is that a tight spring can tear an anchor out of concrete, so ignore anyone who says it. Half compressed is the common target, and only Meyco turns that into something you can put a tape on: coils about 2 1/2 in apart. Strap length is adjusted at the buckle.

Whatever number you use, it moves. Latham says the springs relax within several weeks and Merlin says a cover keeps stretching for two years, so go back round and even the tension up during the season. Uneven springs are what let puddles form.

Wood, pavers, lawn, and a deck that runs out

A brass concrete anchor suits concrete and mortared brick or stone. Everything else takes a different part.

Wood. Two concentric holes: a shallow countersink for the flange, then a 3/4 in hole in the middle for the body. Latham, GLI and Merlin put the countersink at 1 1/2 in across by 1/8 in deep, Meyco at 2 in, so measure your own flange. The center hole runs from GLI's 1 1/4 in to Merlin's 2 in or straight through the boards, and Meyco leaves the installer to judge whether the decking will take the tension at all.

Pavers, brick and stone. What is underneath decides it. Pavers bedded on sand hold nothing, so the answer is an 18 in aluminum tube with an anchor in its end, driven through the paver into the ground. Pavers over a concrete or mortar sub base take a much shorter 9 in deck tube, tapped in with a hardwood block over a bead of masonry adhesive. Latham boxes the warning: that 9 in tube is not for a paver deck with no concrete under it. Bores run from Merlin's 7/8 in to the 1 in of Latham and GLI, because the tubes differ. Test drill a spare piece, and if it cracks, put the hole where two pieces meet.

Lawn. The same 18 in tube works in stable soil with no decking at all, and GLI's needs no pre-drilling. A lawn stake is a lesser thing, capped by Meyco at 20 percent of the anchoring points and never at both ends of one strap, by Merlin at 25 percent, and never in place of a tube where the ground is loose.

When the deck runs out. Latham wants three feet of deck and publishes 36 in as the threshold. Below that you either put anchors off the deck on lawn tubes, or switch to a reduced deck mount system, which lays the spring along the deck edge instead of running it away from the pool. Latham's dimensions come to 20 in of deck: 12 in from wall to cover edge, 2 in to the top of the anchor, 6 in to the edge. Corners and steps run out first. In a merely tight spot a short spring or a D-ring buys a few inches, both at the cost of tension.

What the anchors do for the other six months

They screw down flush, and that is what the hex key is for. Loop-Loc gives the reason in two words: stubbed toes. Close each insert until it sits below the surface of the deck. Casings silt up, so pull the inserts out spring and fall, flush them with a hose, and put a little silicone on the screw before it goes back. No oil, no grease.

Taking the cover off has an order to it. Hose it down while it is still stretched tight, so the debris lands on the deck and not in the water. Release the springs with the rod, never by kicking them. Unhook one end of a strap and the far spring goes slack enough to lift by hand. Then lower every anchor before the cover moves. Merlin is the only manual that spells out that order, and skipping it is what rips covers. Fan fold rather than bundling, and store the cover in its mesh bag hung off the floor so it drains and rodents cannot get at it.

The warnings that come with the cover

These are not our additions. They are the warning label stitched onto the cover itself, and every manual tells the installer to walk the owner through it.

• Stay off the cover. Meyco allows walking on one only in an emergency. Even Loop-Loc, in the document advertising a cover strong enough to hold an elephant, says it does not recommend walking on one, and that children and pets must never play there.
• Children and objects cannot be seen under a cover. Keep them away from a covered pool.
• Remove standing water. A child can drown in water lying on top. Latham will not have a solid cover installed without a drain system or a submersible pump.
• Take the cover fully off before anybody swims, because a partly installed cover is an entrapment risk.
• Inspect it once a year. Anchor Industries treats discoloration, brittle fabric or broken hardware as evidence the thing is no longer a safety cover.

One more comes from the water rather than the label. Every manual requires the level to stay up through winter, because the water carries the snow load, and the allowed drop runs from 12 in to 18 in depending on who made your cover. All of it is written as a warranty condition, so read yours. How far to lower the water goes through it, and the safety covers we carry are cut to the pool plus 2 ft.