This means that NRG Building systems does not recommend the use of colours with an LRV(Light Reflective Value) of less than 40% over The NRG Greenboard Cladding System and NRG Sunhoods and Blades.
LRV is used to descibe how light or dark a colour is-it is actually a measure of how much light is reflected by a surface of that colour.LRV works on black(0%) to white basis(100%)-the higher the LRV,the lighter the colour.
Why is LRV important?
Colours with low LRV absorb light energy and convert this to heat.If the heat cannot dissipate then the coating will heat up to very high temperatures.This can break down the coating system over a much shorter space time span.It can also lead to thermal expansion in some cases.This can create issues at joints like peaking or cracking,and at corners with the render beads breaking away from the Render.
LRV numbers can be found on the database of your local paint/render/texture supplier.
