Flat Roof Felt | Flat Roof Sheet | Roofing Felts

Welcome to the Flat Roof Felt category at Build4Less. As a Flat Roof Felt expert, I'm here to guide you through the various types of products available in this category and help you select the right one for your specific needs.

What is Flat Roof Felt?

Flat roof felt is a bitumen-based membrane designed to create a fully waterproof layer on low-slope roofs. It’s supplied in rolls, commonly 8 m, 16 m or 20 m, and installed as a multi-layer build-up (vent layer, underlay, mineral-finished cap sheet). Options include torch-on APP/SBS felts for professional hot-works and self-adhesive felts for flame-free projects.

Types of Flat Roof Felt

IKO Products

• Glass Fibre Roofing Felt Underlay: IKO Roofing felt are Ideal for robust, long-lasting underlay solutions. These are available in various sizes, like 20m x 1m, catering to different roof sizes.
• Easyseal Self-Adhesive & Heat-Activated Underlays: These underlays offer ease of installation with self-adhesive and heat activation options, providing a fully bonded, watertight finish.
• Adesso & Britorch Cap Sheets: These come in various colours and are perfect for the top layer of roofing, offering excellent waterproofing and durability.
• Shed Roof Felt: Specifically designed for sheds, offering reliable waterproofing at a more affordable price point.

Danosa Products

SBS Underlays and Cap Sheets: These products, such as the Torch On 2.5mm SBS Underlay and the 5 kg SBS Mineral Cap Sheet, offer flexibility and resistance to extreme temperatures.

Bonded and Partially Bonded Underlays: These are designed for varying levels of adhesion, tailored to meet your specific roofing requirements.

Ryno Products

DE50 GRP Drip Edge: An essential accessory for water drainage, ensuring longevity and protection against water ingress.

Selecting the Right Product

For Large Scale Projects: Consider IKO's pallet options like the Glass Fibre Roofing Felt Underlay or Easyseal products.

For Sheds and Smaller Projects: IKO's Shed Roof Felt is a cost-effective, reliable choice.

For High-Durability Requirements: Choose the IKO Adesso or Britorch Cap Sheets.

In Extreme Weather Conditions, Danosa's SBS products are ideal due to their temperature resistance.

Benefits of Flat Roof Felt

• Proven Weather Protection – Bitumen and mineral surfaces of felt roof resist UV rays, rain and freeze–thaw cycles.
• Long Life Span – Modern APP/SBS felt roof from IKO, Danosa, and Katepal offer 20-year+ performance when correctly installed.
• Versatile & Cost-Effective – Flat felt roof is Ideal for garages, extensions, dormers and small commercial roofs.
• Flexible Installation – Choose torch-on for rapid adhesion or self-adhesive for safer DIY or fire-restricted sites.
• Trade Efficiency – Pallet pack availability cuts cost per m² and speeds large projects.

 Applications of Flat Felt Roof

• Domestic: Felt roofing used in Garages, garden rooms, sheds, home extensions and dormer roofs.
• Commercial: Shed roofs used in Office blocks, small warehouses and refurbishment overlays.
• Repairs & Overlays: Felt adhesive are compatible with many existing bituminous roofs when paired with a vent layer.

Installation Tips for Felt Roof

• Prepare a clean, dry substrate such as OSB3 or suitable decking.
• Follow the three-layer system: vent/base → underlay → cap sheet.
• Torch-on felts require trained operatives; observe hot-works safety at all times.
• For self-adhesive products, apply in mild, dry weather and use a heavy roller to ensure full bond.
• Finish with GRP drip edges or metal trims to direct water to the guttering.

Why Choose Felt Roofing from Build4Less?

• Leading Brands – Full range from IKO, Danosa, Katepal and Ryno, all in one place.
• Price Match Guarantee – We’ll match any like-for-like quote.
• Nationwide Delivery – Fast, reliable shipping across the UK.
• Trade Accounts & Pallet Deals – Ideal for contractors and bulk buyers.
• Expert Support – Our team can guide you on product choice and installation best practices.