Energy Efficiency Measure Guide: Flat Roof Insulation (FRI)

This guide explains how Flat Roof Insulation (FRI) works, its benefits, common questions, and the installation process. It also covers maintenance tips and the documents you’ll receive after installation.

Note: All installations must comply with current regulations, which may change over time.

Key Points to Consider:

• Someone must be present during the installation — this can be you or someone you trust.

What Is Flat Roof Insulation?

Flat Roof Insulation (FRI) involves adding insulating material to a flat roof to reduce heat loss.

It helps:

• Keep buildings warmer in winter and cooler in summer.
• Lower heating costs.
• Improve overall comfort.
• Insulation can be installed above or below the roof surface.

Common Misconceptions / FAQs

Do flat roofs need insulation?

• Yes! Without it, heat escapes easily, making your home colder and more expensive to heat.

What’s the best type of insulation for a flat roof?

• It depends on your roof. Rigid boards are commonly used in warm roof systems.

Can I insulate an old flat roof?

• Yes! Older roofs can be upgraded, often during repairs or reroofing.

Will it stop my home from getting too hot in summer?

• Yes! Good insulation keeps heat out in summer and in during winter.

Will I need ventilation fitted?

• Most likely. Insulation can reduce airflow, so building regulations often require ventilation to be installed.

See our ventilation guide for more details .Ventilation | YES Energy Solutions

Installation Overview

FRI is typically installed using one of two methods:

Warm Roof System (Most Common)

• Insulation boards placed on top of the roof structure.
• Covered with a waterproof layer.
• Helps retain heat and prevent condensation.

Cold Roof System

• Insulation placed underneath the roof structure, between joists.
• Requires good ventilation.
• Less effective than warm roofs but still improves efficiency — often used in existing properties with limited ceiling height.

Before Installation

• Roof Inspection: Checks roof condition and structural support.
• Ventilation Assessment: Ensures airflow remains suitable.
• Access Confirmation: Ensures safe access for installers.

During Installation

• Scaffolding (if needed): May be delayed by access issues or severe weather.
• Removal of old roof coverings and insulation: Installers handle waste disposal.
• Insulation System Installation:

Cold Roof:

• Vapour barrier above ceiling (prevents moisture).
• Insulation between rafters.
• Breathable membrane over insulation.
• Roof covering replaced.
• (Tip: A vapour barrier prevents moisture from entering the roof structure.)

Warm Roof:

• Vapour barrier on structural deck.
• Insulation layer on top.
• Waterproof membrane over insulation.
• Roof covering replaced.
• Sealing: All joints, edges, and corners sealed to prevent heat loss and leaks.
• Drainage Check: Ensures proper water flow off the roof.

After Installation

• Scaffolding remains for a few weeks to allow easy access for any follow-up work.

Maintenance Recommendations o keep your insulation effective and long-lasting:

• Inspect the roof twice a year and after storms.
• Remove debris (leaves, branches, dirt).
• Check seals and joints for cracks or gaps.
• Keep drainage systems clear.
• Avoid placing heavy loads on the roof unless designed for it.
• If you notice any issues, contact YES Energy Solutions or refer to your warranties/guarantees.

Handover Documents

After installation and sign-off, you’ll receive:

• Trustmark Certificate
• Insurance Backed Guarantees
• Claim of Compliance
• Workmanship Guarantee
• Manufacturer’s Warranty

Keep these documents safe — they may be needed for future home sales or insurance claims.