Pool Info: Swimming Pool Skimmers
The interface of the plastic skimmer to the concrete pool, plaster, tile and coping creates many opportunities for problems to occur. Common skimmer problems include: separation from the pool wall (beam), freeze damage, leaking or collapsed/ separated pipes (especially if flexible or black poly pipe was used).
Skimmer replacement involves removing the coping stone over the skimmer, cutting the concrete deck on top of the skimmer and the concrete that surrounds it. The skimmer is pulled off the wall and cut from the pipe(s) beneath. The new skimmer is plumbed and secured in place. Concrete and coping is put back.
Pool Skimmer Replacement
Skimmer replacement is usually done at the time of a renovation, or by itself if necessary. Cost comes out to about $1,200 for inground pool. Old pools sometimes used flex piping from the skimmer to the pump, underground. These pipes can crimp, usually where the pipe was bent, especially right at the skimmer. Using chlorine tablets in skimmers for many years can lead to this problem. It’s best to use rigid PVC beneath the skimmer, even if you don’t put chlorine tablets into the skimmer (which you shouldn’t).
To replace an inground pool skimmer, the concrete deck is cut around the skimmer, and then the concrete that encases the skimmer must also be removed. Pry bars and small jackhammers can help remove the skimmer from the wall of the pool. After removal, a new skimmer is attached to the pool wall by plumbing it in place, and pinning bent rebar around the skimmer, pegged into the back of the pool wall.
Build a wooden box around the skimmer, to serve as a form, and pour new concrete around the skimmer body, but only about halfway up the skimmer, to hold it in place against the wall. Pack in plaster mix around where the skimmer meets the pool wall, on both sides and the bottom of the skimmer opening.
Backfill tightly around the skimmer, supporting the block of concrete. Add gravel for the top 3-4 inches above the backfill and concrete. Use plastic or wood crack strips around the skimmer, or use foam to leave an expansion joint for caulking later. Place a few pieces of 3/8” rebar in both directions, around the skimmer, elevating them off the ground. Tie them together so they don’t move. Now mix up a good concrete mix (sidewalks/driveways), and pour it on top of the gravel, up to the very tip lip of the skimmer (remove the skimmer lid and duct tape the top, to keep the skimmer clean). Trowel your fresh concrete firmly, and after 30 minutes, sweep a hose across the surface for texture.
Pool Skimmer Plumbing
Skimmers can have a single hole in the bottom, or they are also designed with 2 holes in the bottom. The two-hole design gives plumbers some flexibility in plumbing, and specifically it allows a pool builder to connect a main drain pipe into the skimmer, in the front hole, and connect the back hole to a pipe that runs to the pump. This is a cheaper way to build a pool, because you don’t have to run a separate drain pipe all the way to the pump, with a separate valve.
If you are replacing a skimmer, with a two hole design, one of the holes will come with a plug. Pull out the plug, apply PVC glue and glue it into place, to seal up the unused hole permanently. Connect your skimmer pipe to the back hole, using a threaded PVC fitting that is either glued in place, or tightly installed with thread sealant. For more skimmer plumbing info, see Inground Pool Skimmer Plumbing Diagrams.
Clogged Pool Skimmers
If you suspect that your skimmer line may be clogged, here are some useful tricks. Use a plumber's snake to try and break up the leaves & sticks (or whatever), or better yet, try a Drain King which attaches to the garden hose and puts high pressure in the line. Connect to a hose and stick into the pipe in front of the pump, and isolate the valve to send all water to one skimmer. Turn on the hose, and then hold a plug at the skimmer end of the pipe, to build up pressure in the line for 5-10 seconds. Repeatedly building up and releasing pressure has a water hammer effect, and is a very effective way to clear a pipe. It’s usually easier to push the clog back toward the skimmer, than to try and force it into the pump.
Leaking Pool Skimmers
If your plastic skimmer has pulled away from the concrete pool and is leaking, use an underwater pool putty to patch it up temporarily and stop the leak. This is a very common pool leak source. You may want to use a Dye test to determine if your skimmers are leaking. Small debris stuck in a small crack is also a clue of a leak. Skimmers can also get cracks in the plastic from concrete expansion/heave. Again pool putty is used to repair this. Some older skimmers may start leaking around the bottom manifold, but this is rare. An epoxy solution can be applied to a dry skimmer to seal up cracks in the skimmer bottom.
Vinyl pool skimmers attach to the wall of a vinyl pool with 4 round-head screws. Two paper gaskets are used, one behind the liner and one on top of the liner. The plastic faceplate, visible on top of the liner, is screwed on tightly to sandwich the liner between the gaskets. A vinyl pool skimmer leaking from the pool side can usually be fixed by replacing the paper gaskets and also the plastic faceplate. Cracks in the body of the skimmer can be repaired with pool putty, or a similar resin/hardener epoxy. Small leaks in a vinyl pool or in a vinyl pool skimmer can often be repaired with Fix-A-Leak emulsion.
SKIMMER BASKETS: It’s important to use the correct basket for best skimmer operation. If your basket floats when the pump shuts off, use a diver’s weight or a stone to hold it down. If your basket breaks under the strain of heavy leaves, try a Debris-Z or Skim Pro basket type. Some of the most popular skimmer baskets are also available in rubber coated steel mesh. If your basket broke and got sucked down into the skimmer well, use larger pliers to yank it out, (likely breaking it in pieces). To vacuum directly into the skimmer basket (instead of into the pump basket), use a skimmer vac plate, made to fit your skimmer model.
SKIMMER DIVERTERS: A skimmer diverter is used to control the flow from the main drain on a combination skimmer (connected to the main drain). For single hole combination skimmers, a vertical pipe is used to cut off or reduce main drain flow, to allow for more skimming action. For dual hole combination skimmers, the diverter is a flat device that sits on the bottom of the skimmer, with a flap to control the relative flow, or suction, from the main drain into the skimmer.
SKIMMER LIDS: They come with screws, useful in high winds. If your skimmer lid takes flight, bolt on a diver’s weight to the center, to hold it down, or use the screws. Also dangerous are broken lids. Replace a broken skimmer lid before someone steps on it and breaks an ankle!
SKIMMER WEIRS: If your skimmer weir (the flapper door or gate) has broken loose, replace it with new. The weir creates a small waterfall into the basket which speeds up water flow, drawing more debris in. The weir also helps to keep debris in the skimmer neck when the pump shuts off. American Admiral skimmers can also use a Floating Weir design, which fits their specific tall basket design.