How Do Thermal Roof Coatings Work?

One should also remember that roof tiles are laid in a certain way – to allow airflow under the tile.  Applying a coating to the exterior of the tile won’t stop that airflow, neither will it stop warm air from escaping through roof vents, soffit vents, through gaps between tile overlaps, around lead work etc. Even a roof without visible vents can be cold and breezy, that’s perfectly normal.

This is why the government and energy companies refuse to offer grants for thermal roof coatings - they simply don’t work.

It is much cheaper to increase the amount of loft insulation you have above the ceiling or to have cavity wall installation installed. 

So next time you see a website or leaflet boasting about how this thermal coating can reduce tile heat loss by 10-20%  etc just remember, very little heat goes directly through the tiles, most goes around it! And for good reason – to prevent condensation.

That is why your loft is always cold in winter, even if the house below is warm.

The purpose of protection is to keep the habitable part of the house warm that is why on most homes the insulation is placed above the ceiling, not on the exterior of the tiles.

Ensure that you have good quality insulation above the ceiling and you won’t have to worry about heat going through the ceiling, let alone through the roof tiles.

Ceramic Paint Protects From Heat

Ceramic-filled or so-called ceramic insulating paint additive technologies promoted by several companies claim to be an”insulating” paint which are used to make exterior house walls cool have been a nonsensical concept from their outset based upon just one law of physics. Since insulation and it associated mandatory “R- value” measurement in the building industries have been long established as the measure of effectiveness for insulation. This is based on thermal mass (thickness & density) and in some varieties, effectiveness in trapping air inside the thick barrier or dense product.  Average paint thickness is a single sheet of paper. Now comes the two sheets of paper thick ceramic-filled paint (up to ten  pieces of paper for some manufacturers), and the claims of insulation value when used to paint any type of exterior wall.  Buildings coated in this way are claimed to be so cool so as to be compared to the space shuttle in how it is protected by ceramic tiles in re-entry to our atmosphere.  This is all smoke and mirrors since the very basis for the R-values claimed cannot possibly be achieved for any substantial length of time by thousandths of an inch of any paint film with insulation elements (ceramic or hollow glass) mixed inside of it.