What Lead Flashing Code Do I Need For My Roofing Job?

When installed and used correctly, lead flashing is probably the most significant roofing investment you can make. Not only is lead exceptionally resilient, with an average lifespan of around 100 years, it also ages well as time passes, acting as both an effective barrier to weather conditions while providing aesthetic appeal. What's more, lead is the most recycled building material in use today, making it extremely beneficial now and in years to come.

Although it's clear why you need lead as a component of your roof, working out what kind of lead you need for your next project can be a less straightforward question, particularly if this is your first time installing it.

At Roofgiant we stock a wide range of Midland Lead and BLM British Lead for you to use during your next project, and to help you out we're going to tell you everything you need to know about codes, thicknesses, the recommended uses of lead and more.

What Are Lead Codes?

Put simply, lead codes dictate the weight, and therefore the thickness, of your lead sheeting. The code very simply corresponds to its weight in pounds (lb) per square foot. For example, Code 3 weighs 3lb per square foot.

Why Are Lead Codes Important In The Installation Process?

When the correct code is used you're helping to guarantee the lifespan of your lead sheeting. In most cases, when the correct lead code is used for your project and installed to a high standard, it will outlive the building itself. Conversely, when thinner lead codes are used incorrectly it will wear out much faster.

Remember: The smaller and simpler the project area, the thinner the lead you can use. The larger the project area and the more beating and shaping you need to do, the thicker the lead.

Although lead has an incredible array of benefits in construction, the central challenges roofers face are environmental changes, and subsequently, fluctuations in temperature. All metals are subject to expanding when exposed to heat and contracting in cooler conditions (especially lead due to its low melting point), which means these changes can take place even in the mild climates of the UK.

If you're wondering what lead thickness you need for your next project, it entirely depends on what you're using it for. On smaller projects, the effects of temperature-induced expansion and contraction will be inconsequential. But when larger quantities of the wrong code are used, this warping will stress the lead to the point that it may split and let in rain, compromising the weatherproof integrity of the building.

Important: Before you begin any project, make sure the rolled lead sheet you're using is made in accordance with British Standard BS EN 12588. This quality standard was put together to ensure that lead sheeting is produced to precise and consistent thickness tolerances and exact chemical composition. When you choose our quality assured products from Roofgiant, you know you're buying sheeting that conforms to a quality that is no less than 99.81% pure lead with a range of standard thicknesses with a tolerance of +/- 5%. Therefore, this guarantees the greatest lifespan lead sheeting, when installed correctly.

Rolled lead sheet
Lead sheet

What Lead Code You Need For Your Next Project

If you want to know what lead code to use and where, use our handy guide below.

Code 3

Thickness (mm): 1.32

Weight (kg/m2): 15.0

Uses: Lead soakers

Code 4

Thickness (mm): 1.80

Weight (kg/m2): 20.41

Uses: Soakers, flashings, vertical cladding, hip and ridge flashing, chimney flashing, apron and cover flashings, pitched valley gutters, bay tops and canopies, vertical cladding

Code 5

Thickness (mm): 2.24

Weight (kg/m2): 25.40

Uses: Flat roofing, pitched roofs, flashing, vertical cladding, hip and ridge flashing, dormers, parapet, box and tapered valley gutters, bay tops and canopies, chimney flashing, apron and cover flashings, pitched valley gutters, vertical cladding

Code 6

Thickness (mm): 2.65

Weight (kg/m2): 30.10

Uses: Flat roofing, pitched roofs, hip and ridge flashing, dormers, parapet, box and tapered valley gutters, chimney flashing, apron and cover flashings, pitched valley gutters, bay tops and canopies, vertical cladding

Code 7

Thickness (mm): 3.15

Weight (kg/m2): 35.72

Uses: Flat roofing, pitched roofs, dormers, parapet, box and tapered valley gutters, pitched valley gutters, bay tops and canopies, vertical cladding

Code 8

Thickness (mm): 3.50

Weight (kg/m2): 40.26

Uses: Flat roofing, pitched roofs, parapet, box and tapered valley gutters, bay tops and canopies

*Please Note: Weight (kg/m2) may differ marginally between suppliers.

If you have any further questions, contact the Roofgiant Customer Service Team who will be happy to help with any questions and queries you may have.