What Is A Warm Roof System?

Many homeowners ask us ‘What is a Warm Roof‘ as they are becoming increasingly popular for conservatory roof replacements.

A warm roof is a flat roof system that has a layer of PIR insulation above the rafters, unlike a cold roof that has insulation inside the rafters underneath the top deck.

Let’s look at the components that make up a Warm roof construction from the outside layer to the inside layer and what each part does.

Warm Roof

A Warm Roof consists of the following components that make up the construction:

Waterproof Layer
PIR Insulation Board
Vapour Barrier Membrane
OSB board
Existing Rafters

 

GRP, FELT, TILES OR EPDM

Depending on the type of roof whethers its pitched or a flat roof construction, you will have a choice of waterproof layers. Pitched roofs typically have tiles or slates, whilst flat roofs either have GRP, Felt or EPDM, whichever waterproof layer is used, the basic construction remains the same.

GRP

Glass reinforced plastic (GRP) is a composite material also reffered to as  fibreglass.It is hard wearing and long lasting,  perfect for flat roofs.

Felt

Felt is used as a waterproof layer on non-habitable buildings such as garages or sheds. Not especially hard wearing.

Tiles

Tiles or slates come in numerous designs and are suited to pitched roofs over 15 degrees, different slates have different pitch tolerences.

EPDM

EPDM is an hard wearing & very durable synthetic rubber roofing membrane (ethylene propylene diene terpolymer).

THE MAIN BENEFITS OF A WARM ROOF

A warm roof system offers many advantages over a traditional cold roof system. A Warm Roof construction can be a simple and cost effective solution that is energy efficient which will reduce heating bills quite significantly.

A well installed Warm Roof will prevent condensation, mold and damp and will last years with the right waterproof layer.

PREVENTS CONDENSATION

A warm roof system keeps the structural deck and the main support structure at similar temperatures inside of the building. This design is especially useful in situations where the original roof has been poorly designed, the internal use has changed or there is a risk of condensation, a warm roof installation will resolve the issues whilst protecting the building from both condensation and damp occuring.

WARM ROOFS PERFECT FOR CONSERVATORY CONVERSIONS

A warm roof build up is perfect for conservatory conversions where homeowners are looking for an energy efficient roofing system.

A Warm Roof construction offers many advantages over a traditional glazed conservatory roof system and can be coupled with a roof lantern, skypod or skylight installation to still allow plenty of light to enter the room.

Best Glaze offer a warm roof conversion for conservatories in Cornwall, if you are looking for an energy efficient roof constructioncontact us for a free, no obligation consultation.

Frequently asked questions

DO I NEED BUILDING REGULATIONS FOR A WARM ROOF?

Building Regulations specify that where a new waterproofing layer is added solely as a means of repair to an existing flat roof there is no requirement to add additional insulation. If the work involves, stripping the roof and replacing elements there is no need to add additional insulation provided:

  • The amount to be stripped and replaced is less than 50% of the total roof area, or;
  • The overall renovation is less than 25% of the building envelope, or;
  • The calculated payback of the additional investment is greater than 15 years, or;
  • It is not technically, functionally or economically feasible – for example, it may not be cost effective due to the cost of raising thresholds, parapet walls etc.

Do Warm ROOFS NEED VENTS?

A warm roof construction does not require ventilation. Any moisture is prevented from entering the main building by a vapour barrier which is the point where moisture disapates.

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