Debunking Six EPS Myths


There seem to be a lot of myths out there about EPS (the expanded polystyrene used inside our insulated panels), so we thought to set the record straight here:

Myth #1: EPS IS A HAZARD TO THE ENVIRONMENT

I wish there was an option to add sound to this blog. If there was such a thing, you would hear a big loud “pum pum” (translation: “wrong answer”) that you hear on game shows such as Family Feud!


EPS is not a hazard to the environment. In fact, it's one of the most environmentally friendly products that you can use in the construction of your home.


Our panels do not contain any volatile organic compounds (VOCs) or other harmful chemicals that can affect your health. The components used to make our SIPs (foam, oriented strand board, and adhesive) meet some of the most stringent standards for indoor air quality. EPS uses pentane which is a non-CFC blowing agent that dissipates shortly after production. It also has no off-gassing.


Even the manufacturing process (steam-expanded polystyrene beads) is environmentally friendly with a 25% lower C02 footprint per R-value by comparison to fibreglass. The beads are made with steam which is compressed together with heat, so there are no greenhouse gas emissions.


We’ve heard the argument that EPS is filling up our landfills and takes an incredibly long time to break down. While this is true, there is definitely a solution to this problem, which brings us to the next myth ….

Myth #2: EPS IS NON-RECYCLABLE

This is the only rigid foam product that is 100% recyclable in New Zealand. Although not accepted by Council kerbside recycling, there are many other places like EXPOL, Waste Management and Mitre 10 that will accept your clean, uncoloured EPS for recycling. Check out this site to find a location near you: https://airpop.co.nz/recycling/

Another benefit of building with EPS panels is that they are cut to size in the factory, which means less wastage. There is a small amount of extra EPS that is sent to the building site used as packaging to protect the panels during transport. These, and any offcuts made on-site are taken straight to a recycling centre.

Myth #3: EPS CONTAINS TOXIC LEVELS OF FORMALDEHYDE

EPS does not contain any formaldehyde. It is a cellular plastic material made up of small, hollow polystyrene balls.


There are very low levels of formaldehyde in the OSB (the timber panels that sandwich the EPS), but these are so minimal that even our bodies produce more!

Myth #4: EPS IS A FIRE HAZARD

Because our SIP walls are completely airtight (they do not contain voids filled with air), there is no oxygen available to feed a fire. In addition, our SIPs contain a chemical-free flame retardant so they don’t propagate fire. In the event of a fire, EPS simply pulls back from the heat source and forms a hard skin. SIP homes perform significantly better in fires than standard timber-framed homes.

Myth #5: EPS IS SO LIGHTWEIGHT, IT WON’T WITHSTAND AN EARTHQUAKE

EPS’ cellular matrix has outstanding impact resistance. So high in fact, that this product is ideal for safety gear such as sports helmets and children’s car seats. EPS’ ability to absorb shock out of movement by allowing some non-permanent flex means that it can significantly reduce the impact of a very severe earthquake.


A SIPS home in Kaikoura proved this point when no damage resulted following the 2016 earthquake.

MYTH 6: EPS ABSORBS MOISTURE

Not true. There is a reason that EPS is used for transporting chilled foods such as raw fish and fruit; it does not absorb water or water vapour. It has excellent thermal and mechanical properties that remain unaffected by humidity, damp or moisture. This makes EPS a fantastic product for keeping your house warm, dry and damp-free.


I hope these myth-busters have put your mind at ease about using SIPs in your build. If you would like more information about EPS, please contact us.

28 views0 comments

Recent Posts

See All