What is gunite?
Gunite is a mixture of cement, sand, and water that is sprayed on a surface under pneumatic pressure.
Gunite, along with a rebar frame, is used to create the structure of the pool. Plaster is then applied to create a water barrier. Gunite is porous and should not be used by itself to construct a pool. There must be a water barrier between the porous gunite and the water. If the plaster is not thick enough, it could allow water to seep through the gunite. This will result in water loss that is difficult to isolate without draining the pool. There are methods for repairing a pool that is not properly sealed with enough plaster.
WARNING: DO NOT DRAIN YOUR POOL WITHOUT A PROFESSIONAL PRESENT. EXTENSIVE DAMAGE TO THE POOL AND SURROUNDING PROPERTY MAY OCCUR.
How do gunite swimming pools crack?
Gunite pool structures are susceptible to cracking when water from behind the structure permeates the porous voids of the structure and changes temperature, effectively expanding and contracting.
Cracking in gunite can also occur when the surround ground shifts. The change in the ground can happen due to a change in the water table, earthquakes, or freezing and thawing of the ground.
Weak points in the structure will succumb to the pressure resulting in fissures.
What are the repair methods for gunite swimming pools?
Seeping water through plaster
If the pool is losing water because the plaster was not applied correctly and water is seeping through to the porous gunite, the solution is to identify the faulty area and apply additional plaster. There are different repair methods depending on the nature of the problem. If the plaster or grout line is in poor condition, a replaster may be required. If it is a very small leak, a waterproof sealant can be poured into the pool. This method is the easiest fix, however, there could be complications if all the steps are not followed correctly.
If the plaster is cracked, the use of pressurized polymer is the best solution. It adheres to the structure, bonding the pieces together as a flexible hinge. The repaired crack is then hidden from view by reapplying a plaster coating to the appropriate thickness.
If the gunite has a large crack, we have solutions to secure and repair the structure. To stabilize the structure, we will lock the gunite structure together and then perform a polymer crack injection to seal the leak. Lastly, we will replaster over the mended crack and polymer.
Contact American Leak Detection for professional repair of your gunite pool.