If you have read any of our other pages on this site, you will already know that scammers use underhand tactics such as outrageous claims and even lies to sell roof tile coatings that are not needed.
The latest scam? – Thermal roof coatings.
There are several companies making wild claims about thermal roof tile coatings, they claim that homeowners can shave several hundred pounds each year off their heating bills by having their roof tiles coated with a coloured paint.
There is however a fundamental problem, even if the roof tile coatings have thermal properties (and that is questionable), most roofs in the UK are vented, so any thermal tile coating would have no effect whatsoever on the performance of the roof to retain heat.
Why Insulate a Vented Loft Space?
Not to worry – the loft insulation placed just above the ceiling will keep the house below warm.
Here is a statement from Rushcliffe Borough Council, taken from their website:
Following reports of door-to-door salesmen in the Rushcliffe area offering to coat your roof, claiming it will help it to retain heat, Trading Standards have issued the following warning:
Trading Standards has received reports about businesses cold-calling and offering a roof cleaning and coating process. It is claimed the coating process provides thermal insulation. Roof tiles are designed to allow air to circulate in the roof space, so simply painting the tiles will provide no benefit to your homes’ thermal efficiency. In addition, the use of high-pressure hoses to clean the roof can actually damage tiles and force water in to the roof space. You may be tempted by a very low initial quote but the price may rise when the job starts. The work may be unnecessary and the quality poor.
So How Do Thermal Roof Tile Coatings Work?
They don’t work – it’s a scam.
They are just another attempt by crafty roof coating companies to fool you into buying a questionable product.
Most lofts in the UK are cold in the winter, that is perfectly normal and certainly not a problem provided you have good insulation above the ceiling. A coating applied to the exterior of the tiles will not change the fact that the loft is cold, even the best roof coating product will only have the slightest of thermal properties, certainly not enough to counter the natural ventilation caused by roof tiles that are overlapped and by roof vents which are now mandatory on all newly built homes.
The Loftspace is Designed to be Vented
One should also remember that roof tiles are laid in a certain way – to allow an airflow underneath the tile. They are not airtight and neither should they be. 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 leadwork 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 tile 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. Both of these can be done with government/energy company grants. More information can be found on the MoneySavingExpert website.
So next time you see a website or leaflet boasting about how this thermal tile coating can reduce tile heat loss by 10-20% 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 toasty.
The purpose of insulation 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 wont have to worry about heat going through the ceiling, let alone through the the roof tiles.