Working on an Existing Roof: Repairs and Re-covering

Are you planning repairs or considering re-covering your existing pitched or flat roof? You typically won't need to submit a Building Control application for these tasks, provided your project meets specific criteria:

• The work affects less than 25% of your entire 'building envelope' – this refers to all the parts of your property that enclose the usable space, including walls, floor, roof, windows, doors, roof windows, and roof-lights; AND

• Your work impacts less than 50% of the total roof area.

Always exercise extreme caution when undertaking any work on an existing roof. Modifying or removing any roof elements can alter its fundamental structure and function, potentially causing issues like movement, cracks in your walls, or even a complete collapse. You must ensure the roof remains stable and performs effectively after your project is finished.

However, you will need Building Regulations approval in several key situations:

• If your project exceeds the percentage limits mentioned above for the building envelope or roof area. In such cases, you might face additional requirements, such as having to ensure the entire roof's thermal insulation is sufficient.

• If you carry out any structural alterations to the roof.

• If your chosen new roof covering material would perform significantly differently in a fire compared to the existing covering.

• If you use a new covering material that will increase the overall weight of the roof by 15% or more.

Re-covering Pitched Roofs

When you replace an existing pitched roof covering with a different type of material – for example, changing from slate to tiles – you will most likely require Building Regulations approval. This process helps to ensure that your roof maintains its structural stability (especially if the new material is significantly heavier or lighter), meets essential fire safety standards, and complies with current energy efficiency requirements.

If the new covering's weight varies considerably from the old one, the existing roof structure may need to be modified or strengthened to accommodate it. We strongly advise you to consult a qualified structural engineer or surveyor before you start any work to ensure your roof can safely support the new material.