Insulating Paint: What Is It, and Does It Work?

Insulating paint was introduced to the building industry in the late 1990s as an applied coating of liquid insulation for walls and surfaces that would improve the efficiency of a structure’s thermal (or heat) management.

This article takes a look at insulation paint: what it is, how it works, and why its claim as a leading insulation resource against the elements is troubling certain experts in the building industry.

What Is Insulating Paint?

Insulating paint, or insulative paint, is designed to coat surfaces in order to boost heating and cooling efforts, and its potential to lower energy costs and reduce energy footprints attracted homeowners almost immediately.

Insulation paint, if used on exterior surfaces, reflects heat and sunlight coming from any direction toward the painted surface, and prevents heat from drifting outside toward cooler temperatures.

The thicker the insulating material, the slower the movement of heat across it; it was hoped that the addition of insulation paint to an already insulated barrier would simply continue the efficiency cycle.

Manufacturers since the early 2000s began experimenting with and producing their own brands of insulating paint. These contain either ceramic or glass microspheres (more about these shortly) premixed into the product or as an additive you can stir into regular paint yourself.

Insulating paint used in a bathroom
Insulating paint can help bathrooms avoid condensation buildup.

Does Insulating Paint Actually Work?

It is agreed that insulating paint is not a replacement for regular insulation, but rather an added resource that improves the efficiency of the insulation that is already installed.

Standard insulation works by keeping heat out during the hotter months and the heat in during the cold months. So in summer, we don’t want heat coming in and in winter, we don’t want warmth getting out. It is building insulation that regulates the ability of heat to flow.

Insulating paint used on its own has very little impact on the heating efficiency of a building.

Construction experts advise that in terms of insulation, it’s essential to have a “strong building envelope” of thick walls, a correctly installed insulation layer, and proper windows. Without these essentials, no amount of insulation paint is going to have an impact.

However, if the base insulative structures are present, the application of insulating paint can minimalize heat transfer. However, these impacts can only be estimated, and so while the product is of interest to homeowners, it has not yet prompted huge respect from builders.

The trouble is that insulation paint manufacturers have not been able to provide independent test results to support claims of improved thermal insulation performance over standard products.

Can You Insulate A Wall With Paint

The notion of insulating a wall with paint to reduce heat transfer first arose at NASA when damage caused to the space shuttle during re-entry into the atmosphere provoked the creation of a protective coating which was sprayed on at the time of painting.

This protective coating contained chemicals and “filler materials”, and particles, which both deflected heat and protected surfaces.

The idea was later adapted and transferred to house paint, which when dried, formed a radiant heat barrier that converted ordinary house paint into “heat-reflecting thermal paint”.

Manufacturers stated that these products reduced the work of conventional insulation used in walls and ceilings, and that the true ability of insulating paint was to reflect or block heat from any surfaces (fireplaces, heaters, and radiators) as well as sunlight.

Clients were advised to use the paint as a premix or as standard paint with additives, which were stirred in by hand and applied to any wall or surface.

Application of the paint only required following normal painting procedures, such as the preparing and cleaning of surfaces.

The properties of insulative paint were simple, familiar, and attractive, and as there were no real methods available to gauge the effectiveness of the paint’s insulative properties, consumers relied instead on strategic marketing information.

Does Painting Help Insulation?

Standard paint will not improve your current insulation heat flow score, however, certain paint products, such as thermal paint and insulating paints are claimed to have insulation and thermal barrier properties which can impact the efficiency of your insulation.

All homes have an R-Factor, or a thermal insulating factor, which refers to how well a two-dimensional barrier (such as a wall, ceiling, or layer of insulation) resists heat flow.

“R-Factor” is a building industry term, and values go from 1.5 to 7, with the higher number indicating the most efficient heat flow control.

Insulation sheets come in different materials and structures  (including foil and foam) and they are not all constructed in the same way. This means that each type of sheet is created with different R value rating.

Therefore, a more precise question is: does paint increase the R-Factor of two dimensional barriers, and if so, what kind of paint, and what are the unique properties that allow it to function as a form of insulation.

Insulating paints, for example, contain microscopic “ceramic spheres” which create a “radiant heat barrier” when mixed with regular interior or exterior paint, and it is this precise technology that is claimed to provide the insulative properties.

Building experts have commented that when the goal is to reduce the amount of heat transfer produced by the sun, any white or light coloured standard exterior paint will perform as well as any other paint because all paints that are light in colour reflect heat away from surfaces anyway.

Recommended Buys

The following products are all thermal supportive and will therefore improve the general insulation score of your home, providing that efficient insulative structures are already present.

Final Thoughts

Despite its “scientifically proven” claims to efficiency and success, insulating paints have yet to really prove themselves in the building market. The judgement that the product really has no significant advantage over ordinary paints has not yet been overturned.  However, the phrase “no significant advantage” still has advocates interested and homeowners prepared to give it a go.