Built-up Felt Roof

Built-up Re-enforced Bitumen Membranes (RBM) (more commonly referred to as ‘Felt Roofs’) are the most established all-roofing solutions, which were founded over 90 years ago. These systems became the product of choice for the logistically more difficult Flat Roofs in the early 1940s. Quick to install, cost-effective and easy to transport the raw products to even the most inaccessible roofs, Built-up Felt Roof Systems quickly made a name for themselves during the post-war re-build.

A Built-up Felt Roof consists of:

• Supporting timber joists.
• Structural Roof Deck usually comprised of 18mm OSB3 conditioned structural sterling board or WBP (Weather and Boil-Proof) plywood.
• A vapour control layer
• An optional layer of rigid insulation (required for home extensions to comply with current Building Regulations for the thermal insulation of a Flat Roof, but not essential for outbuildings where heat loss is not a concern).
• Layers of quality Roofing Felt. This can be either two layers or three layers depending on which system is applied.

Suitable for new build and refurbishment projects, Built-up Felt Systems can be installed via pour and roll, hot torch or a cold adhered method. HS RoofClad always comply with the Safe 2 Torch scheme regulations, therefore limiting the health and safety risks presented by hot works. Cold adhered options by their nature remove these risks.

This solution can be installed on a wide range of surfaces including but not limited to metal, Single-Ply membranes, Asphalt Felt and more. This solution can be a highly economical option when there is no requirement to remove the existing roof.

A few of the key benefits are detailed below:

• Fire Protection – Systems are available that satisfy even the most stringent fire regulations. Class A protection can be achieved (in accordance with BS 476) with relative ease.
• Elastomeric – Most modern felts are designed to be elastomeric, meaning they can move with your building. Settlement cracks will be comfortably bridged without compromising the waterproofing.
• Insulant Compatible – Built-up Felt Systems are compatible with all the modern insulants including EPS, XPS, Phenolic, Foamglass and even the ecologically friendly wool and straw-based systems.
• Design Compatible – The lightweight and resilient properties of Built-up Felt Systems means that they can be adopted in almost any Flat Roof design – Submerged, Green, Inverted and Warm Roofs are all possible.