SEMCO Liquid Membrane in Plastered Pools

SEMCO Liquid Membrane in Plastered Pools

One of the more common pool finishes are plastered pools since it is hard finish, however it is also relatively porous. Its porous nature means that it will often show stains easier and faster than other surfaces. Increased maintenance is therefore necessary if you want the plaster to last for several years or else blemishes, stains, or streaks could appear within several months or several years after the plaster was applied. Erosion and etching or pitting are not uncommon, worst cracking could appear and moisture would penetrate into the pool’s concrete. 

In Summary the downside of plastered pools:

  • $ 4.00 - 7.00 per sq ft for re plastering pool
  • Porous surface which requires more maintenance 
  • Non Flexible hard surface could lead to cracks
  • Erosion, etching or pitting not uncommon.

Exploring Alternatives

In order to re-finish a plastered pool in bad condition is either to re-plaster it again which means a large investment is needed as prices range from $ 4.00 to $ 7.00 or another type of coating like epoxy from various manufacturers can be applied on top. However epoxy is another hard non-flexible coating which could develop cracking over time and it most cases, epoxy is not UV-Stable which would result in discoloration over time.


SEMCO Liquid Membrane™ is a great and cost effective way to repair and restore your pool. As a liquid waterproofing membrane it can be easily applied and provide a long lasting protective membrane. Its non-porous surface is easy to maintain, UV-stable and its flexible nature (1,300% Elongation) 

With its active adhesion properties, SEMCO Liquid Membrane™ provides a chemical adhesion and enables mechanical cross-linking to applied surfaces with 400+ PSI adhesion, creating a perfect bond for long lasting protection.
For fully submerged application like in pools, the coverage is approximately 100-150 sq ft per gallon at a total thickness of 60 mils at a cost break down of less than $ 0.60 per sq ft. The ease of application allows SEMCO Liquid Membrane™ to be applied onto the surface either by roll or spray application.

Since SEMCO Liquid Membrane™ can be applied directly on plaster, a complete removal of the existing plaster is not needed which saves time on the project and also the cost of labor. Only loose parts of plaster would be needed to be removed prior to the application and prep work to start the application on clean surface.

Pool re-finishing example

As an example we have a 7 year old pool that has been plastered and its condition is deteriorating over time. The plaster has started to form small cracks which lead to slow water loss.

With the costs of having to re-plaster the pool at a cost $ 4.00 - $ 7.00 per sq ft, the price to complete the pool and having it finished by the start of summer was not a viable option at the time. Epoxy paint would be the cheaper alternative to plaster, however it can only be applied to bare surfaces or previously painted surfaces with epoxy paint. On top of that epoxy is not UV stable and would break down the surface.

The easiest, most cost effective and reliable option is SEMCO Liquid Membrane™. Since the pool has been already drained, any loose plaster pieces were taken off, the surface prepped with bio degradable cleaning detergents by SEMCO to take off any magnesium deposits or efflorescence and let the surface dry completely.

Once the surface has dried, the application process could begin. Application was done simply with a 1/2” woven nap roller, for larger areas a sprayer can also be used.

Once a total thickness of 60 mils (3 coats) has been applied, the pool has been successfully re-finished and results look great.