What is Polyisocyanurate or Polyiso

What is Polyisocyanurate or Polyiso

It is made by combining three main components, MDI or methylene diphenyl diiocyanate 8,  polyol, and a blowing agent. When these three components are mixed along with small amounts of catalysts and exothermic chemical reaction causes the liquid blowing agent to boil evaporation is an exothermic reaction.

So let’s look at an endothermic one. This expands the foam, creating tightly packed gas filled cells. The form has to be sprayed against the substrate to form a rigid panel, so all Iso panels are faced with either foil or paper. The foil faced panels are considered impermeable because they create an exterior vapour barrier. They should never be used with an internal vapour barrier because then you’ll have vapour trapped between these two barriers which can cause mould and mildew.

Let’s Discuss the Advantages of Polyiso.

It has the highest are value pinch compared to EPS and XPS. it’s about an R6 to and R 6.5. Polyiso is also stable. Over a large temperature range minus 100 degrees Fahrenheit to 250 degrees Fahrenheit, it can be used on roof systems with hot asphalt. In fact, Polyiso is used on 70% of commercial roof construction. Polyiso also has a very low water absorption and low vapour transmission. It’s not affected by oil based waterproofing compounds insecticides.

All fertilisers when it is properly protected, the polyiso industry uses pentane as blowing agent which has zero global warming potential and zeros on depletion potential. One of the disadvantages of Polyiso is that it’s more expensive than EPS or XPS. If 4 foot by 8 foot by one and sheet at Home Depot costs $21.50 to cents. Polyiso uses a halogen fire retardant KPIs, which is dangerous to health. It doesn’t work very well in temperatures below 50 degrees Fahrenheit.

Because the trapped gases start to condense and they no longer act as an insulator, it is the least eco friendly option of the three, and it has the worst thermal drift.