Bay Roofs in Lead: Design & Installation Guide
Projecting bay windows are a distinctive architectural feature. Correctly detailed bay roofs in lead provide long-lasting performance and a heritage finish. This guide covers code selection, bay sizing, joints and fixings in line with Leadwork Standards.
1. Code Selection
Bay roofs are often small in area but highly visible. Code 5 lead is the standard choice, with Code 6 used on larger or more exposed bays.
2. Bay Sizes & Joints
Divide coverings into bays no longer than 1.5 m for Code 5 or 2.0 m for Code 6. Wood-cored rolls or expansion joints are required for larger bays.
3. Falls & Drainage
Even small bay roofs require a fall of at least 1:80 to prevent ponding. Outlet or drip detailing should be planned to shed water away from the wall face.
4. Decorative Detailing
Heritage properties often specify decorative rolled joints, scalloped edges or standing seams. These must be designed to maintain waterproofing while enhancing aesthetics.
5. Finishing & Maintenance
Apply patination oil immediately after installation. Regular inspection is recommended, as bay roofs are prone to debris buildup in gutters and drip edges.
FAQs
What lead code is best for bay roofs?
Code 5 is standard, with Code 6 recommended for larger or exposed bay roofs.
Do bay roofs need expansion joints?
Yes, on larger bays or where lengths exceed recommended maximums. Wood-cored rolls are common for heritage detailing.
What fall should a bay roof have?
At least 1:80. Even small bay roofs need falls to avoid ponding and staining.
Can bay roofs be decorative?
Yes, scalloped edges or decorative rolls can be included, but they must not compromise waterproofing.
Do bay roofs need patination oil?
Yes. Apply immediately after installation to prevent uneven staining and prolong lifespan.
Next in the series (Post 13): Lead Dormer Windows (Advanced Detailing) — cheeks, aprons and heritage-style finishes.
