What is Gunite Pool Resurfacing?

gunite pool resurfacing on a backyard pool with black interior finish

As time passes your gunite or concrete pool will age along with everything else. Over time the interior finish will fade and look a little less pristine each year that passes. Eventually, you may wonder what you can do about your failing pool surface? You may hear about resurfacing from pool contractors or friends and find yourself asking, what is gunite pool resurfacing?

What is Gunite Pool Resurfacing?

Gunite pool resurfacing is the process of restoring or replacing the interior finish. Resurfacing a gunite pool can be done a couple of different ways. In this article, we will explain each method and give you a few things to be aware of.

Gunite Pool Resurfacing Method 1: Chipping

First, and most extreme is to start by chipping out the interior finish. The interior finish of the pool is approximately 1/2” thick and is troweled onto the concrete surface. The concrete surface is often referred to as gunite or shotcrete, since the process to place the concrete is called gunite or shotcrete.

Once the interior finish is completely chipped out with jackhammers, the surface is floated with what’s called a brown coat. This is a cementitious product used to even out the rough surface left by the jackhammers. Then once the brown coat is cured, if you’re redoing the tile, it’s time for tile at the waterline. Finally, the tile is complete, it’s time for the interior finish.

Gunite Pool Resurfacing on a pool spa combo

Gunite Pool Resurfacing Method 2: Remove And Bond

The less invasive method of renovating a pool is to remove only a portion of the interior finish up at the tile line and down maybe 12 inches or so. Then, carefully inspect the remaining interior finish areas for cracking and chipping. Any loose material must be removed. Then often a pressure wash of the whole interior finish will be completed prior to the bond coat. The bond coat is a cementitious product meant to bond old plaster to new plaster. Once the bond coat is complete and again, the tile is redone, if you’re doing that, it’s time for the interior finish.

Gunite Pool Resurfacing Method 3: Acid Wash

The least invasive method of resurfacing a pool finish is to do an acid wash on the existing finish. This is done by draining the pool and spraying an acid solution onto the surface of the pool. This burns the top layer off the plaster, exposing fresh plaster beneath. This can make the finish look fresh and clean.

However, because the acid only reacts with the cement between the sand and pebble particles and not the sand and pebbles, the finish will be rougher after the acid wash than before. An acid wash is a great way to bring an aging finish back to life though, and many times it’s the first attempt at restoring a pool back to its former glory.

Gunite Pool Resurfacing on a white commercial pool

Resurface With Caution

Note: whenever you are renovating a pool you must bring the suction outlets into compliance with the Virginia Graeme Baker Act. This means your main drains and covers need to be changed and brought into compliance as a part of your renovation work. Make sure to ask your pool company how they plan to do this as a part of your renovation.

Bottom Line

The ability to resurface a gunite pool is one of the reasons we like gunite pools so much. They can be built once and restored numerous times over their lifespan. You don’t need to keep the tired old finishes of a dated swimming pool, you can always resurface and bring them into the modern era.