What is ThermoWall

Chemical Composition of ThermoWall

ThermoWall is a kiln-dried aminoplast foam, where the “amino” term chemically refers to a urea nitrogen-based polymer. ThermoWall insulation is generated when the dry ThermoWall resin is combined with water and brought together with a Foaming Agent Catalyst (FAC) under air pressure. The FAC mixes with compressed air to generate a foam substrate that contains the catalyst needed to complete the polymerization process.  The polymer forms around the air bubbles contained in the foam and becomes aminoplast foam.

HeatSavers have exclusive rights to import and ThermoWall from the United States of America, where it is produced by CFI Foam.  For more technical information from the manufacturer of ThermoWall refer to the downloadable files at the bottom of this page and also their own website:


Chemical classification of ThermoWall Resin

ThermoWall resin is technically classified as a urea-formaldehyde (UF) material, however this material is functionally different from Urea Formaldehyde Foam Insulation (UFFI) materials used during the 1970s. The older materials associated with UFFI were liquid resins that required formulation with an excess of formaldehyde that was needed to maintain the shelf life of the product.  Liquid resins continue to polymerize after they are manufactured, therefore an excess of formaldehyde was needed to maintain the activity of the resin during transportation and storage from the point of manufacture to the point of use. The excess formaldehyde contained in these solutions was as high as 10%, which was directly responsible for the off-gassing issues associated with these liquid resins.

The kiln-dried resin used by ThermoWall was not available at the time of the general ban that was placed on the use of UFFI materials in the late 1970s, both in the US and in Canada.  ThermoWall resin is produced by reacting carefully controlled amounts of urea and formaldehyde under a heat and pH-controlled environment, which is stopped at the point that contains a specific molar ratio of polymers called “pre-polymers” based on polymethylol urea.  This mixture is controlled by the manufacturing process itself that limits the formaldehyde content to 0.17% by weight.  At a specified point during manufacture, the liquid resin is kiln dried into a free flowing powder that removes any volatile organic compounds (VOCs), including free formaldehyde, which normally exists as a gas or liquid (e.g. liquid > 37% formaldehyde).

The final product is a dry UF powder resin that contains no liquids, VOCs, or free formaldehyde.  The material is mixed just prior to installation and therefore does not require an excess of formaldehyde to increase the shelf-life of the older UFFI products. After mixing with water, ThermoWall resin is catalyzed using a mild acid which is dispersed in the foaming agent.

ThermoWall MYTHS

1. Walls only represent around 20-25% of 
heat loss

If only the ceiling is insulated, then heat will find the next easiest escape route which is typically the walls and windows.
After the ceiling, walls represent the next largest area of the
envelope of the home to be insulated. 

Furthermore, the R value achieved by insulating walls is generally greater than that which can be achieved by double glazing windows.
Most percentages used for heat lost in a house are normally based on an average house with a stud height of 2.4m. In many older homes the stud height can be far greater than 2.4m, some as high as 3.6m. This adds to the overall wall area, and naturally a greater percentage of heat loss.


2. Formaldehyde in ThermoWall causes 
health problems.

FALSE. ThermoWall has been proved to be an extremely safe 
product. ThermoWall contains small amounts of formaldehyde 
which dissipates during the drying/curing process. Once this 
process is complete New Zealand and international testing shows that the presence of formaldehyde in the home is no greater than pre-installation background levels.

Trace levels of formaldehyde are found in many household products including carpet and particle board such as that used in kitchen cabinetry. It is used as a food preservative, occurs wherever there 
is combustion and if found naturally in the environment. 
It is produced in small amounts by most living organisms as part
of normal metabolic processes. 


3. Foam insulation was banned in Canada. Is ThermoWall the same stuff?

NO. Early forms of these foams were banned many years ago in the USA and Canada. The USA overturned the ban not long after due to lack of evidence to support the claims made against the foams.

In Canada, when the claims were investigated, there was no sign of houses with issues. Even though the product resembles the original versions, technology has progressed significantly since then to ever improve and make better foam insulation materials, installation techniques and equipment. An excerpt from an article in the Toronto Star, below, sums up the situation in Canada.

“UFFI is one of the most thoroughly investigated, and most innocuous building products we have used. Simply put, no one has ever proved urea formaldehyde foam insulation to be a health concern.

An eight-year long trial and appeal in Quebec confirm this conclusion. The UFFI scare arose without any proof and still casts an unjustified cloud over houses with the insulation.

The Carson Dunlop report concludes that "those who have UFFI in their homes should enjoy their houses, and sleep well at night.”