FAQs - Frequently asked questions

Can tapered insulation be used on an existing flat roof?

Yes. Tapered insulation can be designed for both new and existing roofs.

For refurbishment projects, the existing roof construction should be assessed before a tapered insulation scheme is designed. The survey and design should consider the existing roof dimensions, drainage points, falls, obstructions, roof condition and the proposed new roof build-up.

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How is a tapered insulation scheme designed?

A tapered insulation scheme is designed around the geometry and drainage requirements of the individual roof.

The design process should consider factors such as:

  • Roof dimensions and geometry
  • Drainage outlets and gutters
  • Existing falls and backfalls
  • Rooflights and other obstructions
  • Required insulation performance
  • The structural deck
  • Waterproofing system
  • Required roof build-up
  • Upstands and perimeter details

Gradient provides a design service that produces a pre-designed, dimensionally accurate tapered insulation solution with detailed layout drawings.

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What is a warm flat roof construction?

A warm flat roof is a roof construction where the insulation is positioned above the structural roof deck, keeping the deck and structure on the warm side of the insulation.

A typical warm roof build-up may include the structural deck, vapour control layer, insulation and waterproofing system. The exact arrangement depends on the roof construction and waterproofing system being used. Warm roof construction can provide continuous insulation across the roof, helping to reduce heat loss and improve the thermal performance of the building. The complete roof build-up should be designed to meet the required thermal, moisture, structural and fire performance criteria.

What is tapered insulation?

Tapered insulation is insulation manufactured or designed with varying thicknesses to create a fall across a flat or low-slope roof.

Rather than using insulation of a constant thickness, a tapered scheme uses different insulation thicknesses to form designed falls that direct rainwater towards outlets, gutters or other drainage points.

Gradient provides bespoke tapered insulation solutions designed around the individual roof geometry, including new and existing roofs.

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