How to Spot and Fix Bad Pool Plaster Jobs

Written by Michael Dean
July 5, 2023

fixing bad pool plaster work

If installed correctly, pool plaster can last 15-20 years. But if the plaster is not installed adequately or cured properly, it may deteriorate much faster.

Recognizing a bad plaster job is an important skill that can be challenging for amateurs. Bad plaster installations can be caused by various factors, such as poor weather, an inexperienced plastering crew, and poor plaster mixing. If you get stuck with a lousy plaster job, you must recognize it as soon as possible and fix it to avoid ruining your investment.

In this article, I will cover a few common ways to recognize poor plastering and possible ways to avoid getting a bad job done in the first place.

Main Takeaways

  • Common plastering issues from bad plaster jobs are spot etching, delamination, mottling, spalling, and crazing.
  • The average cost of resurfacing a pool is $6500-7000 per 1000 sq foot.
  • Ask friends and neighbors to recommend good pool plastering crews (preferably ones they have previously contracted) to you to employ a dependable crew.

How to Spot and Fix Bad Pool Plaster Jobs

Many different issues can arise with your pool plaster. If you are experiencing any of the below issues, it may be due to bad pool plaster jobs. Let’s go over these issues that may come up and discuss how to fix them.

Spot Etching

Spot etching refers to the unexplained white spots on pool plaster. While these seem harmless at first, they can become a problem in the long run. If left untreated, it can damage the plaster and cause issues with strength and leakage. Spot etching normally occurs when too much calcium chloride is added to the plaster mix.

pool plaster etching

How To Fix

Spot etching can be fixed in one of three ways, depending on the intensity of the problem and the type of pool plaster you have:

Sanding: Sanding down the plaster in the initial stages of spot etching can be an excellent way to prevent more problems down the line. Sanding removes the spot etching and reveals a smooth plaster layer underneath. Make sure to research what type of sandpaper and sand block you should utilize, depending on your pool plaster.

Chipping it off: If the issue has already reached later stages of deterioration, chip out the plaster in affected areas and replaster it using underwater plaster or epoxy putty. This method will save you a lot of money long term.

Replastering: Replastering your entire pool may become necessary if the problem is left unchecked for too long. If the spot etching has spread to large areas of your swimming pool, contact a pool professional and have them advise whether or not a complete replastering is necessary.


Spalling occurs when surface layers of the plaster have cracked and chipped off from the walls. This happens due to improper troweling during the pool plaster process. Spalling appears as irregular, rough patches on the walls of the plaster.

pool plaster chipping off

How To Fix

To fix this issue, start by sanding down the affected area. Then you can either replaster the patch with underwater plaster or epoxy putty. Unfortunately, if the spalling occurs in a large area of the pool, you may need to resurface the entire pool.


Crazing or craze cracks refer to small clusters of cracks on the surface of pool plasters. They look like very fine and shallow spider-webbed cracks and are usually considered minor issues. That said, they affect your pool’s aesthetic and could be a symptom of a larger problem.

This problem occurs due to an excess amount of shrinkage of the superficial layer of the pool plaster due to various reasons ranging from an imbalanced pool plaster mix to the excessive drying of pool plaster before filling the pool. It occurs very early on in the stage of plastering and can be hard to spot unless dust or moisture renders them visible.

How To Fix

It is generally easy to fix crazing. To fix it, simply chisel or sand away the affected areas of the plaster. Then use underwater plaster or epoxy putty to fill in the area. Use a trowel to smooth it down to an even layer.


Delamination refers to the separation of the pool plaster from the concrete layer underneath. If this occurs in a new pool, 9 out of 10 times, this issue arises due to shoddy workmanship. Particularly when the pool surface is poorly prepared for plastering. However, delamination can also occur over time due to environmental conditions. A weak bond or bond failure between the gunite and pool plaster is responsible for this issue.

Delamination can usually be easily detected and observed as the separation of the top layer, resulting in an air or calcium cavity. The air cavity can sometimes be in the form of small nodules.

pool plaster delamination

How To Fix

Delamination may be fixed in the following ways:

Epoxy putty: If you’re lucky, this problem may occur in a small area of your pool. If this is the case, delamination can be fixed through a quick repair job using epoxy putty or underwater pool plaster. Use a paint chipper to remove the bumps or nodules and replaster according to the manufacturer’s instructions.

Resurfacing: Delamination is often a death sentence for your pool’s structural integrity. Severe cases of delamination mandate replastering the entirety of your pool with the help of qualified professionals.


Mottling or discoloration is easily spottable. Any speckled variation of color that appears sporadically on your pool’s surfaces is known as mottling. It is a very common issue caused by a fairly wide range of factors, including incorrect trowelling, uneven application, or improper water balancing. Mottling is mostly harmless and is a surface-level issue.

pool plaster mottling

How To Fix

You can resolve a case of mottling by:

Acid wash: An acid wash could help even out the discoloration issue.

Blow torch: Blow torching can be an option to lighten a light discoloration on dark plaster. However, this method can often do more harm than good and may weaken the plaster,

Replastering: Draining and resurfacing your pool is the only foolproof way to fix mottling, but you should only do this as a last resort. Since mottling is an aesthetic issue, try to avoid replastering if you can.

Average Cost Of Repairing A Bad Plaster Job

The average costs of repairing a bad plaster job depend significantly on the issue. For example, if you are facing the complete overhaul of your pool plaster and seeking a replastering job, you need to add pool drainage and refilling costs to expected expenses. Draining your pool can cost you $125 to $225 to have it done by professionals. Resurfacing or replastering expenses then depend on the size of your pool. On average, an approximate cost is around $7,000 per 1,000 square feet, with labor costs ranging from $45 to $65 an hour.

On the other hand, if you are fixing just a small area of your pool, you can get away with simply purchasing underwater plaster or epoxy putty, which costs between $10 to $90.

How To Avoid A Bad Plaster Job 

A good plaster job is the best way to avoid the above-listed issues in the first place. Therefore, you should not take the quality of the workmanship lightly, as plastering your pool is an expensive and time-consuming process.

The company you contract to plaster your pool should be a top-tier crew with plenty of experience and first-hand knowledge on anything and everything related to pool plastering. As with any product or service you buy, do your research, scope out the company you wish to contract and seek reviews or feedback regarding the company from previous customers. You could also ask friends or neighbors who have had excellent plastering jobs completed on their property for referrals.

And when you finally speak to the crew you are interested in contracting, ask them these questions so that you know you will get quality service and workmanship:

  • What cement mix do you plan to use during the troweling process?
  • What has been your timeline for previous plastering projects, and what is your projected timeline for my project?
  • How will you ensure no delays occur during the plastering process?
  • What are the additional mixtures, materials, and finishing coats that you will be applying to the plaster, and the names of the manufacturers/brands?
  • Under what weather conditions will you be planning to schedule the plastering process for my project?
  • Can you show me photos of your previous projects before and after the curing process?
  • What is your estimated budget for the project, and what is the breakdown of the costs? 

You can note down their responses for further research later and even discuss them with an independent pool expert for any potential red flags or issues you might need help identifying as a novice.

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