Inspecting Liquid Vinyl Siding

by Nick Gromicko, CMI®, Roberta Farsetta and Kate Tarasenko

Liquid vinyl siding (LVS) is an ultra-thick material – 10 to 15 times thicker than a coat of paint – that combines the durability of exterior vinyl siding with the versatility and appearance of new paint. It’s smooth to the touch and looks like paint, but, unlike traditional vinyl siding, it does not change the architectural integrity of the home. Home inspectors can benefit from recognizing LVS and understanding how it affects (and does not affect) the exterior cladding of a home.

LVS Basics

Liquid vinyl siding has been around since 1985.  The technology behind it consists of a proprietary formula of vinyl resins and polymers.  LVS can be applied over many surfaces, including concrete block, wood, masonry composite siding, stucco, and galvanized steel. It also can be applied to existing vinyl, wood, and aluminum siding. LVS has a 30-year manufacturer’s warranty.

Liquid vinyl siding is a system consisting of a base coat and the LVS coat. The base coat performs two important functions: providing the means to adhere to what it is applied over; and to bond with the LVS top coat, allowing it to expand and contract with the base coat. The base coat is manufactured using a process whereby vinyl resin is suspended in an acrylic emulsion. This process is called emulsion polymerization. After it is applied, it goes through a curing process, where solid matter suspended in the liquid emulsion comes together to form a film. This special base coat is made to work in conjunction with the vinyl top coat. Because of the exceptional bonding ability of the primer coat, which also contains vinyl activators, it’s able to expand and contract at the same rate as the LVC top coat, and promotes fusion with the vinyl.

The vinyl resin contained in the top coat provides a high permeability rate, which is responsible for its breathability. Tiny gaps form between spherical vinyl particles that create a mechanism for moisture vapor to escape. The small particles of vaporized moisture are able to squeeze between the gaps and pass through the film. But that doesn’t mean that the coating is permeable. Liquid vinyl is water-resistant and non-permeable.

Application and Warranty

LVS can be applied via spray, roller or brush. It requires true diligence when preparing surfaces for application, which includes repairing cracks in concrete, brick, masonry, and stucco, and scraping away any loose materials and thoroughly cleaning the surfaces. Where the material is being sprayed, and depending on the existing surface, some contractor actually dig a small trench around the foundation’s perimeter to allow uniform and complete coverage. Preparation is key to a good application, which must also be performed by a manufacturer-authorized distributor in order for the 30-year transferrable warranty to be valid.

Environmentally Friendly

Liquid vinyl is eco-friendly because it is low in VOCs (volatile organic compounds), which makes it environmentally safe.  LVS is compliant with California's CARB rules, and it meets or exceeds all EPA standards. LVS has no phthalates or BPA (bisphenol A) plasticizers. Since vinyl is a thermoplastic material, it biodegrades in soil. More than 50% of vinyl’s composition is derived from common salt, making it more energy-efficient to manufacture than conventional paint and stain.


LVS manufacturers claim many benefits, including that it’s virtually maintenance-free, it has a long service life, and it may be the best-performing exterior coating commercially available.

There are many advantages to using liquid vinyl siding for both residential and commercial structures.

  • Appearance:  LVS is available in a broad spectrum of off-the-shelf and custom colors. Since the color is formulated within the LVS, it always looks new and never dulls or ages the way paint does over time. Many communities and historic districts that maintain strict architectural regulations approve of this coating because it does not change the architectural appearance of a home.
  • Maintenance:  The unique composition of LVS resists dirt, fading, mold and mildew. There is virtually no maintenance required. It needs to be simply hosed off to keep it clean. There is no need to even power-wash the structure because the siding has an anti-static property that resists dust and dirt. Because the material is not permeable, moisture does not become trapped beneath the surface, which would otherwise lead to the growth of algae, mold, and other organic spores. LVS also contains an elastic property that allows it to stretch up to 645% and still recover its initial shape. Therefore, no matter how much settling occurs, no splits or cracks occur, and the siding will continue to keep the structure sealed from the elements.

  • Durability:  LVS outlasts ordinary exterior paint. It reflects heat, which protects a structure from extreme temperatures and the wear and tear those fluctuations can cause.

 Inspecting LVS

It may be somewhat difficult for an inspector to tell if LVS has been applied to a home’s exterior cladding. The finished product will have a satin-like finish, not flat or glossy like paint. It is quite thick. There will be no obvious cracks because of the filling characteristic of the product. In many instances, the product is applied via sprayer, and significant masking is required to protect items what should not be coated. So, the inspector can look for signs of unwanted overspray. If a homeowner says that the dwelling is coated with LVS, the inspector can ask to see the warranty paperwork, which should also indicate that it was applied by an authorized distributor.

Also, the inspector can look for obvious defects, such as failures in the material or its application. An improperly prepared surface will affect the product’s adhesion. Look for signs of dirt under the paint, cracks, blisters, and peeling areas. Although LVS is durable, it is not exempt from manufacturer defects or application failures. The inspector should document any defects in the exterior cladding, regardless of whether s/he can confirm the presence of LVS.



Roberta Farsetta has been involved in the inspection industry for nearly 20 years. An inventor and entrepreneur, she has performed inspections in New York State, and is an indoor air quality expert. She is also a trained and experienced architectural draftsperson. A freelance author and researcher, Roberta is married to Certified Master Inspector® Joe Farsetta, a nationally recognized educator, and Chair of InterNACHI’s Ethics and Standards of Practice Committee. 

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