If your home features an in-ground swimming pool, consider yourself blessed. For one, the pool is sure to increase the valuation of your home. The right poolside landscaping ideas can make it the perfect spot to entertain friends and family. And there is no better way to beat the summer heat than soaking in the pool.

However, if your pool has a concrete or gunite shell, an important part of maintaining the structural integrity of the pool involves periodically replastering it. Here is an essential guide to swimming pool replastering, just so you know why replastering is important when you need to consider replastering, the process, and costs.

What is replastering?

In simple terms, replastering means adding a layer of plaster to the surface of the pool or in other words, to the sides and the bottom of the pool.

Plaster is important to your swimming pool for multiple reasons. For one, it is the waterproof layer that is essential for your pool to be usable. Both concrete and gunite, while being sturdy shell materials, are porous in nature. Without the ½ inch layer of plaster that pool installers add to waterproof the pool, your pool would keep emptying out with time through these shells.

In addition to waterproofing, plaster also feels much better than concrete does and adds oodles to the visual appearance of the pool.

How often does your pool need replastering?

While some experts say you’d ideally need to replaster your pool every five to seven years, that time period can be stretched to almost 20 years. The lifespan of your pool plaster depends on how often you clean your pool, the pH levels of the swimming pool water, and general maintenance.

Telltale signs of damage to the plastering include the plaster cracking and pitting. As the plaster wears away, the pool surface will feel uneven, bumpy, and uncomfortable. With time, the plaster is also sure to fade and lose its visual appeal. If the concentration of iron or copper is high in the water, the plaster and the entire pool itself can experience staining, making the pool look dirty and uninviting.

Of course, stop-gap measures exist, including patchwork and in some cases, adding a layer of plaster over the existing one. However, you will eventually need to hunker down and pay for a professional swimming pool replastering.

Keep in mind though that while you may be able to handle some aspects of replastering a pool as a DIY activity, some aspects, such as trowelling an entire pool will seem insurmountable unless you are a professional plaster mason yourself. It is best to leave the entire job to professionals. 

The process

Here is a look at the process of replastering a swimming pool.

Draining the pool

empty pool
  • The pool will need to be completely drained before you can begin work on the project.
  • Check local and state laws regarding draining swimming pool water in your local area. There are very strict laws regarding where and how pools need to be drained.
  • Chlorine is detrimental to local water ecosystems. If you use chlorine in your pool, use products such as Chem Out to remove all traces of chlorine from the water before you drain it.
  • Also, remember to expose and open the hydrostatic valves before you drain the pool. These valves allow excess table water under the pool to drain into the pool. If you do not release these valves, they can generate enough hydrostatic pressure to sometimes lift the whole pool shell off the ground.

Prep work

  • A diamond blade grinder will be used to make a ¾ inch cut underneath the tile band on top of the pool. An air chisel is used to start the chipping process an inch and a half below the cut at an upward angle. 
  • The purpose of this is to chip off space under the tiles where the plaster can be installed without a bulge.
  • Space around the inlet and drain fittings as well as underwater light niches will also need to be chipped.
  • All trained professionals wear protective glasses and gloves during this process since it is fairly dangerous.

The acid wash

  • Straight muriatic acid is poured over the walls and floor of the pool, and allowed to rest for a few minutes.
  • This is done to etch out and rough up the old plaster so the new plaster layer has something to adhere to.
  • The acid will need to be neutralized before it can be disposed of.

Read more: How to acid wash a pool

Plastering the pool

pool replastering
  • Apply a bond coat and allow it time to dry.
  • White portland cement and marble dust are mixed in a plaster rig. The mixture is then pumped into the pool.
  • The mixture is shot onto the walls and the floors. Plasterers use special peg shoes to ensure they leave minimal marks on the plaster.
  • The surfaces are smoothened out using long trowel strokes.
  • The entire process takes between two to four hours. It is done quickly so the new plaster can begin curing underwater at the earliest.
  • Pool paint is applied after this and allowed to dry before the pool is filled.
  • Early mornings or late afternoons are the best times to plaster swimming pools.
  • If swimming pools are not filled to the brim with water as soon as the paint dries, you are likely to see cracks within a day or two, depending on the weather.

Post plastering care

Here are some tips on how best to care for your swimming pool after it has been replastered.

  1. During the first year, the plaster will continue to cure underwater, and during this time, the water pH levels will rise drastically. You will need a pH controller to keep it in the ideal range of 7.2 to 7.4.
  2. During the first month, test the water quality on a daily basis and make sure the new plaster is brushed at least twice a day using a hard brush. This will make plaster dust rise, making it easier to remove it through the filtration system.


On average, the cost to replaster a swimming pool measuring around 120 square feet is around $200 in materials and $500 for six hours of labor. That means a total cost of $700 for a 120 square foot pool.

Read more: How to clean a pool

An essential guide to swimming pool replastering was last modified: October 14th, 2022 by Narayan Shrouthy
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There are times when plastering is useful, but you have to know how to differentiate when deeper touch-ups are necessary, with cement or replacement of entire parts.