Pool Info: Pool Surface Repair & Replacement
Concrete Swimming Pool Repair
As a gunite or concrete pool begins to age, the plaster will require occasional repair. Cracking, hollow spots, sometimes called “pop-offs”, and chipping are not uncommon. Plastered pools also experience worn areas that can become severe, with the gunite below the plaster is showing. Pool plaster is not structural, but is the waterproofing membrane over top of the porous concrete pool shell.
Most pool plaster repairs can be done by the homeowner. With the right tools, the right materials, and a little know how, you can repair most small cracks and chips without too much effort. The following is a step by step guide to making typical pool plaster repairs.
Swimming Pool Crack Repair – empty pool
- Cut the crack out 1/2” deep and extend the length of the crack one inch on both ends. You will need a 4” or 7” grinder or concrete saw with a diamond blade. Cut the crack with a dovetail fashion. Be sure to wear ear and eye protection, heavy gloves and long pants.
- Rinse the crack, and allow it to dry, then wipe away any dust or debris.
- On large and deep cracks, apply a bead of sealer along the length of the crack leaving 3/8” space to allow for plaster to cover the caulk.
- Mix pool patch and bonding additive to the consistency of peanut butter.
- Lightly moisten the concrete edges of the crack. With a flat trowel or putty knife, apply your pool patching mixture to the crack. Gently push the mix into the crack to remove all air.
- Scrape off any excess material, and gently use a wet sponge to match the consistency of the existing surface. If the pool plaster repair won’t be under water for more than a few hours, cover it with a moist towel or blanket to keep the patch from drying out before the pool repair is covered with water. This will prevent shrink cracking of the plaster patch from drying too fast.
- Fill the pool as soon as possible and go swimming! It cures best underwater.
Wet Swimming Pool Crack Repair – Full Pool or Underwater
If you don’t wish to drain the pool, you can still patch small cracks or chips in the plaster. Use a mask or goggles to see clearly underwater.
- First, open the crack a bit by raking a flathead screwdriver down the crack or around the edge of the area to be patched. Use a wire brush next to remove any algae, dirt or loose material.
- If there is algae or dirt that can’t be removed, use a 2” pipe with a 90° fitting, to apply either liquid chlorine bleach, or muriatic acid – but not both at the same time (!) directly to the crack.
- Choose your underwater pool patch material.
- For a pool putty patch, just mix equal parts of A & B, using some pool water to help mix the resin and hardener. For a plaster chip or pop-off, roll into a ball and push into the area and smooth out the edges. For a plaster crack, or around skimmers, roll into a ‘snake’, and push into the crack, smoothing out the edges with your fingers.
- For a Fast Set plaster mix patch, mix the material on the dry side, and roll into a ball shape. Quickly take the patch ball underwater and push into place with a trowel. Smooth out the edges with trowel or fingers.
Swimming Pool Plaster Patching
- With a hammer and chisel, remove any loose plaster that is not bonded to the pool surface. Drag the floor of the pool with a heavy chain and listen for hollow spots, or tap the pool floor with a wooden pole, or listen for a hollow sound while spraying the pool with a strong stream of water. Chip up any delaminated areas, wearing gloves and eye protection.
- Chisel some divots and pock marks into the surface that will be patched to help your new plaster patch bond to the existing surface. Acid wash the surface to be repaired.
- Figure out the surface area to be patched. Mix your pool patch to a peanut butter consistency. If the plaster is a custom color (grey, black) you can add cement dyes or pigments.
- Mix the plaster mix and the acrylic bonding agent together with water. Mix to the consistency of peanut butter.
- The best way to apply the mix is with a “pool trowel”, a stainless steel trowel with rounded ends.
- Moisten the surface with your sponge or a fine mist, or apply bonding additive like Acryl 60.
- Apply the plaster mix with your trowel. Push the mixture into the corners and divots. Trowel it to push out air bubbles and smooth the patch, feathering the edges. Wait 15 minutes and trowel the patch smooth again, with light pressure. If weather is hot, or the patch looks excessively dry, spray a mist of water and smooth it into the plaster patch.
- Keep the pool repair moist until it is under water. Cover the patch with wet burlap or an old bed sheet, if the pool water won’t cover the patch within 4-6 hours, or during hot temperatures.
- Fill your newly patched swimming pool immediately, or as soon as possible, as plaster cures best when underwater, but cures too rapidly if left uncovered. Repair your plaster as a last step, if you have other repairs to make to the pool before refilling with water.
Swimming Pool Plaster Replacement
There comes a time in every plastered pool’s life, where it becomes necessary to Replaster, or replace the whitecoat, aka marcite finish. It’s often an aesthetic decision, done to improve the appearance or reduce roughness of the plaster. New pool plaster will also hide cracks or chips, or cover rough and stained plaster with a soft new coat of plaster, about 3/8” thick, right on top of the old plaster.
Here are the steps involved in inground pool plaster replacement – but I do not recommend this as a DIY project. Small plaster repairs yes, but plastering the entire pool is best left to the experts – a crew of 5-6 guys that get the job done in 3 hours, and begin refilling the pool immediately. If you want to help (or save money), you can offer to provide them with a prepped pool (steps 1-4), ready for new plaster. But let a pool plastering company apply the new whitecoat, Trust me on this one.
- Drain pool, and open hydrostatic relief plugs
- Cut and chip underneath perimeter tile, trim tiles, around wall fittings, lights and floor drains. This is often done with pneumatic hammers, to chip away existing plaster, so the new plaster can be applied flush to tile and fittings set into the plaster.
- Chip out any delaminated areas on the walls or floors.
- Acid wash the pool surface aggressively to etch and roughen the surface.
- Apply a scratch coat primer to assist in bonding new plaster to old (this step may be omitted by some plasterers).
- Apply new plaster from a truck mounted hopper and pump, through a large hose, spraying on the plaster.
- Wearing spiked shoes, 4-6 workers begin troweling the plaster smooth over the walls and floors.
- After one pass over the entire pool, the plasterers replace the spiked shoes with sponge shoes, and make another pass over the entire pool, gently troweling smooth the surface, and feathering the edges.
- Wrap a sock around one or two garden hose ends, and begin filling the pool immediately.
- Leave instructions for the homeowner or pool operator, for new plaster start-up procedures.
Fiberglass Pool Repairs
You can repair small cracks in your fiberglass pool without too much trouble. Follow the step by step guide below for simple crack repair. You will need a fiberglass repair kit from your local paint supply, or marine supply store. Automotive kits can also be used.
Fiberglass blisters and bubbles can be repaired the same way. Please remember, you will never get a perfect color match and you will always see the repair. The only way to avoid this would be to resurface the entire swimming pool with a new gelcoat finish.
- Disk sand the entire area around the crack to remove loose dirt and debris. Brush clean with a acetone to remove fine dust.
- Apply the bond coat to the crack area. Let this set and dry until it becomes tacky. If the crack is leaking water, patch with hydraulic cement, then apply the bond coat.
- Catalyze the polyester putty, and apply it to the crack using a putty knife. Allow the putty to dry, and then sand the area smooth.
- Apply 2-inch masking tape around the perimeter of your repair.
- Apply a gel coat with a smooth, small paint roller, or use an air sprayer for best results.
- Lay down your fiberglass cloth, using enough to overlap at least two inches on each side of the repair area. Then saturate the fiberglass cloth with another layer of the gel. Roll the area using the rib roller, being careful to eliminate air pockets from under the fiberglass.
- Allow the repair to dry. (24 to 72 hours, depending on temperature and weather conditions).
- After the surface has cured to the touch, sand the surface, apply the finish coat.
- Make sure the surface is completely dry before you proceed from one step to the next.
Fiberglass Pool Refurbishment
A fiberglass pool shell begins to look faded and tired after many years. If there are also cracks or surface imperfections, you may wonder what options exist to refurbish the surface and restore the original luster.
There are two options, a new gel coat application sprayed onto the surface, or when structural problems exist, the fiberglass pool can be strengthened with multi-layered sprayed-on fiber coatings. Both of these fiberglass pool renovations are best left to professional boat, car or pool applicators, but if there are no such professionals in your area, a new gel coat could be applied by the pool owner, with careful attention to prep, mix and application. Practice with equipment and process outside of the pool, before jumping in and re-gel coating an entire fiberglass pool.
In cases of severe damage or destruction of a fiberglass pool, the entire shell can be replaced with a new shell of similar size and shape. A fiberglass pool can also be converted to a vinyl or plaster in-ground pool type, at a considerably greater cost.
Vinyl Liner Pool Repair and Patching
Most rips and tears in vinyl lined pools can be patched with a simple vinyl patch kit. Today, most pool vinyl patch kits can be used underwater or above the water level. You can also use If you can drain the pool down to patch the leak, it will be easier to make the patch. The following is a step by step guide to patching your vinyl pool liner with a traditional patch kit. We also have Flexible Sealer and EZ Patch 28, which squeeze from a tube and smooth with your fingers.
- Clean the area to be patched to remove oil/dirt, and sand lightly with wet/dry sandpaper.
- Cut your vinyl patch material about 1” larger than the hole on all sides. Cut the vinyl patch material in a circle or oval shape so there are no corners to peel up.
- Apply the vinyl glue to the area around the hole, and to the patch itself. For an underwater patch, apply the vinyl liner glue to the patch only, and fold the patch over on top of itself, loosely. Submerge the patch, unfold it, and quickly stick it on.
- Press the patch onto the area being patched. Rub all of the air from under the patch, and take extra time to rub the edges all the way around the patch.
- Check on the patch every 5 minutes for half an hour, to smooth the patch edges again.
Vinyl Liner Replacement
Unlike replastering or re-fiberglassing, replacing the vinyl liner is something that can be a successful DIY pool owner project. Like anything else, preparation is the key to a good finished product. Here’s the process for replacing an inground vinyl pool liner. Aboveground pool liners are replaced in similar fashion, with some exceptions.
- Measure your pool with the dealer measuring form, choose your pattern and place your order for the inground pool liner. Also order new faceplates and gaskets for skimmer, drain and returns.
- Drain pool to a location far from the pool. If your pool is situated in a low lying area, with a high water table, choose a dry time of year, or month, to drain the pool.
- Remove the wall fittings faceplates and screws (skimmer, returns, drain, light), with a large #3 Philips head screwdriver.
- Pool lights should be removed from the niche. Shut off power and tie/tape a string to the light cord at the junction box. Pull the light cord out of the niche completely, and leave the string in the conduit, to help pull the light cord back through, after the liner is installed and nearly full of water.
- Use razor knives to cut the liner at the base of the wall all the way around the pool.
- Lift the liner bead out of the track, and cut the wall vinyl into strips. Roll up and remove from pool.
- Step sections have many screws; use a cordless drill with a #3 Philips head attachment. Store all screws from steps, skimmers, lights, returns – in their own separate zip bags.
- Clean the walls with a broom, blower or water. If any areas are rusted, scrape and paint. Very bad rust can be covered with sheet metal and duct tape. If walls are especially rusty and crusty, consider using wall foam to protect the new liner.
- Duct tape vertical seams in the wall. Inspect around skimmer and returns for rust damage around the opening. Scrape and clean, paint with Rust proofing paint.
- Cut the floor liner into sections, roll them up and remove from the pool.
- Sand floors will need to be retroweled extensively, to restore a smooth, divot free surface. You can add a small amount (< 1 yd.) of masonry sand but be careful not to raise the floor level.
- Cement or vermiculite floors can be cleaned with a broom or blower, patching any divots or rough areas.
- Clean up the skimmer and main drain screw holes, and use glue or tape to place the interior gasket in place (the gasket that goes under the liner).
- Open new liner box and unroll liner, locating a marking to indicate Shallow or Deep end. With 4 people to help (one for each corner), pull the liner over the pool, and pop the liner into the track in or near each corner. Use pennies or Liner Lock to help hold it up in areas temporarily, as needed.
- Two people can start at one end of the pool, and each work opposite each other, pulling the liner up and locking it in the track, while pulling the slack behind them, so the liner hangs flat and tight in the track.
- Set up a 5hp wet/dry vac, or a pool liner vac next to the long side of the pool. Run the vac hose behind the liner, between the liner and the wall. Duct tape up the area where it goes behind the liner, and also duct tape up the skimmer lid. Step sections can be sandbagged and taped, or place a sheet of old liner over the step and seal up any air leaks.
- Turn on the blower, to remove the air from behind the liner and pull the liner tight against the walls and floor. If you see any wrinkles, lay down on the deck and lean over the pool and pull them towards the side (you may have to turn off the vac for a minute). Work out any wrinkles by pushing them to spread them out, or pulling them toward a wall.
- Walk carefully down to the deep end and tighten up the main drain ring and gasket, then cut out the vinyl inside the ring and install the main drain cover. Begin to fill the pool, keeping vacuum running until pool water level is 6” over the shallow end floor.
- Install step section plates and screws on 3-sides, over the step gasket, before water rises above screw holes. Use a cordless drill for safety, and tighten all screws fully, then install trim covers.
- Screw on the wall faceplates and gaskets only when the water level has risen to them. Screw tightly using a #3 Philips head screwdriver and then cut-out the vinyl inside of the faceplate.
- When the pool is full, start the filter, balance the water and begin sanitizing the water.