When it comes to roofing, there are a wide range of regulations for property owners to follow. Things like pitch, roof structure and the materials used are all regulated. But so too is roofing insulation, which is critical to a roof’s performance. So, what exactly do you need to know? Read on as we discuss flat roof insulation regulations.

Why roof insulation matters

Every building has an envelope which separates it from the external environment. It’s made up of the foundation, walls – including doors and windows – and the roof. If any of these physical components is poorly insulated, it allows heat to easily escape the building and makes it much harder to keep the interior warm. That’s why roofs require effective insulation. However, it’s not just about making things easier for property owners. Government building regulations are also concerned with the conservation of fuel and power. If buildings don’t have the right level of roof insulation, they’re going to need more fuel to keep them warm which means more impact on the environment. To combat this issue, new roofs have long-had to meet building regulation standards for insulation (U values). Since 2006, this has also applied to refurbishment on existing flat roofs.

What the Building Regulation says

Part L of the Building Regulation outlines two separate regulations for flat roof insulation. It depends on whether the roof is on a new property or an existing building:

  • New flat roofing insulation – The roof must have a U value of 0.13 W/m2K or lower.
  • Existing flat roofing insulation – The roof must have a U value of 0.18 W/m2K or lower.

Cold deck vs warm deck

Roofs can have two types of insulation: warm deck or cold deck. Warm deck insulation is when insulation is placed at rafter level, so the deck stays warm, while cold deck leaves the deck cold with insulation at ceiling level. For pitched roofs on existing properties, there are slightly different U values depending on the type of insulation they use. However, the values are the same for flat roofs regardless of their insulation type. What this does affect is how insulation is installed. As a general rule, most flat roofs require a minimum of 100mm insulation in the voids to achieve the right level of insulation. If the roof is insulated with a cold deck, it typically requires a ventilated cavity of around 50mm to allow air to flow and prevent moisture build up.

Can we help?

Roofing regulations can be complex without the right training, that’s why it’s important to get roofing experts for any new flat roof or flat roof refurbishment. DPR Roofing Barnsley is a team of roofing specialists with over 29 years’ experience. Our fully-trained team is ready to tackle any job. To arrange a free quote today, or get more information about any of our services, contact our team today.