Frequently Asked Roofing Questions (FAQ)

What is a flat roof?

A flat roof is a roof that has a slight slope to allow water to drain. They are typically less than 10 degrees and are commonly used on commercial buildings and some modern residential buildings because of their cost-effectiveness. There are different types of flat roofs, including warm and cold. Some materials we may use include felt and asphalt. Learn about how we install flat roofs.

How much does a flat roof cost in London, UK?

The cost of a flat roof in London varies depending on the materials used, the size of the roof, and labour costs. N.H.R.B.S. offers competitive, transparent pricing, including a 10 year insurance-backed guarantee on all roof replacements.

What is a pitched roof?

A pitched roof has a steep slope, typically greater than 10 degrees, and is designed for efficient water run-off. It is a common choice for residential properties in London and around the UK, providing excellent durability as well as potentially offering space for an attic or loft.

Do you need planning permission for a pitched roof?

In most cases, replacing or modifying a pitched roof on an existing building does not require planning permission. However, when replacing more than 25% of a roof, we are required to inform the local council with a building notice, which we will handle for you. You will then receive a a building control compliance certificate from council after they check our work. If you have a historical listed building and have concerns, we have extensive experience working on these type of properties and can advise you.

How do you install lead flashing on a pitched roof?

Lead flashing is installed by cutting grooves into the mortar joints, inserting the lead, and securing it with clips or wedges. The flashing is then dressed into the roof's surface and sealed to ensure it is watertight. Lead is a durable material, making it ideal for roofing. Learn more about how we use lead for our roofs.

How do you calculate the pitch angle for a roof?

To calculate the pitch angle, you need to measure the "rise" (vertical height) and "run" (horizontal length) of the roof. Divide the rise by the run, and then take the inverse tangent of the result to find the angle in degrees. We are experienced at this and always confirm our calculations before beginning construction of your roof replacement. Read more about our quality policy to find out about our workmanship.