One major thing to remember is that pool plaster can change colors or overall look as it sets and cures. Plaster is hand applied, so it is normal to expect slightly uneven areas, and the color will not be 100% uniform throughout the pool. Also, as the plaster cures, the appearance will change slightly.
Why is curing your new plaster important? The installation of a new plaster surface causes fluctuations in the water chemistry. The alkalinity, pH and calcium levels will rise while the surface is curing. The new plaster is susceptible to staining and discoloration during the first four weeks.
Gray (or grey) mottling discoloration is due to high amounts of calcium chloride added to a plaster mix, and or late, hard and dry troweling. This issue has nothing to do with the water chemistry or the way the pool was originally started up with chemicals when initially filled with water.
60% of the curing or maturing process of a plaster finish occurs in the first 28 days and will continue over the next 8 to 10 months. This curing process causes the alkalinity, pH, and calcium levels to rise on their own as the pool strengthens and seals the new finish.
An acid wash every 5 or 10 years will strip scale film to restore and brighten plaster beneath. As an added benefit, replacing (old) pool water improves water conditions, often making water balance and scale management easier.
Standard white plaster will do what it is supposed to. It will be watertight and serve its function for that 10 to 15 years depending on maintenance. But pebble finishes, properly installed and maintained, will last 20 to 30 years or more. It is the most durable finish our industry has to offer.
Colors: Pool plaster can be dyed any color by the use of colorants added to the mix. Lamp black dye, in different amounts, can produce shades from light gray to dark black. Hues of blue and red can also be easily and cheaply added to the marcite mix.
Prior to plaster: 3 weeks
While the gunite is curing, the beginning of many other processes will begin. During the three-to-four-week curing process, you can expect to see tile and coping take place (plus any additional stonework that may include grills, fireplaces, and firepits).
Sometimes, depending on severity, the appearance can be improved by an in-pool acid wash. Extreme cases may require the pool to be drained and acid applied directly on the finish. For quartz pool finishes, an acid wash might be able to reduce the appearance of mottling.
On Average, Replastering is Every 10 Years
So how often do you need to replaster a pool? The short answer is about every 10 years. However, it's important to consider the factors mentioned above, as they are typical signs that your pool needs to be replastered.
Pool plaster will immediately start hydrating when mixed, and 86% of the cement in the plaster will cure within the first 28 days. This is why timely filling and dedicated startup maintenance is critical to any new pool plaster project.
Mottling is a natural phenomenon that occurs in all pool plaster to some extent. It is affected by environmental factors such as sunlight, heat, wind, water content, water temperature and humidity which are not within the plasterer's control.
Shrinkage or Surface Cracks
Surface cracks can be seen in the plaster and generally don't mean that you have a leak. Surface cracks don't usually run through the shell of the pool and cause leaks. These are also pretty normal and can be repaired easily.
Check cracks and crazing are quite normal and very rarely, if ever, leak. If the crazing is unacceptable or seem to be more than normal, consult the plaster company. They are able to create a plaster slurry and fill in these cracks. Major cracks or structure cracks are caused by soil movement.
The plaster is manufactured as a dry powder and is mixed with water to form a stiff but workable paste immediately before it is applied to the surface. The reaction with water liberates heat through crystallization and the hydrated plaster then hardens.
Gunite. Gunite pools are among the longest-lasting pools on the market. When gunite pools are properly installed they could potentially last 100+ years. They are extremely durable and totally customizable.
The best thing to do is spray the gunite with a hose 2-3 times a day for a week or so after it is shot. Helps keep shrinkage cracks to a minimum... so a light rain a few hours after it is shot is actually good for it. The only thing I would be concerned about is a heavy rain while they are shooting it...
Gunite will cure better and properly if kept moist. You can apply a light mist of water hours after the gunite application is completed. The next days you can apply a heavy spray to moisten the gunite. You cannot apply too much water.
Options for Gunite Pool Resurfacing
Plaster is made from a mix of cement, white sand or marble aggregate and water. Most people choose white, but it can be dyed the color of your choice.
You need to raise the level of your chlorine – shock the pool – and maintain that high level until all the algae is dead. This may take 3 to 4 days. RUN THE FILTER 24 HOURS A DAY. You must maintain that high level of chlorine.
Here is why: Sunlight is white, which is made up of all the colours of the spectrum. The molecules in pool water absorb light from the red end of the spectrum when sunlight falls on the water. By removing the red, the light which ends up being reflected has a slightly blue hue which can vary in richness by water depth.
The two most likely causes are calcium scaling or copper stains.
There are two primary water colors for your swimming pool, blue and green, and the shades of blue or green are determined by numerous factors. The main determiner for water color is the background dye in the finish. If you want green water, the finish should be green, brown or tan.