leadwork standards

THE LEAD LADS® / PROJECT ARCHIVE

Lead Orangery
Roof

Complete replacement of the leadwork surrounding a glazed orangery lantern at Grade II listed Vicarage House near Tadcaster, incorporating Code 5 lead bays, perimeter gutters, wood rolls, movement joints, lantern flashings and a new sump outlet.

KIRKBY WHARFE · TADCASTER · GRADE II LISTED · ORANGERY LEADWORK

Explore the Project

01 — THE PROJECT

A complete lead weathering system around a glazed lantern

The Lead Lads® renewed the orangery roof leadwork at Vicarage House in Kirkby Wharfe, near Tadcaster, North Yorkshire.

The roof is organised around a central glazed lantern, with fully supported lead bays and perimeter gutters forming the weathering system between the lantern structure and the surrounding masonry.

The replacement package included the supporting timber deck, Code 5 lead roof bays, gutter linings, wood rolls, expansion details, lantern upstand cladding, apron and cover flashings, and a new sump outlet to improve drainage from the roof.

SPECIALIST LEADWORK →
LEADWORK STANDARDS →
CODE 5 LEAD →

LOCATION

Kirkby Wharfe

PROGRAMME

Approx. 10 Days

LEAD CODE

Code 5

ROOF TYPE

Orangery + Lantern

02 — THE ROOF

A flat lead roof arranged around a central lantern

The orangery roof combines several different weathering conditions within a relatively compact area.

The principal lead bays surround the glazed lantern, while separate perimeter gutters collect runoff and direct it towards defined outlets. The lantern upstands, coping walls and roof transitions all introduce junctions that require individual lead details.

This makes the roof a connected system of bays, gutters, flashings and drainage components rather than one continuous sheet covering.

Key elements

  • Fully supported Code 5 lead bays
  • Central glazed lantern
  • Timber core rolls
  • Perimeter lead gutters
  • Lantern upstand cladding
  • Apron and cover flashings
  • Movement joints
  • Sump outlet and rainwater discharge

03 — THE DESIGN PRINCIPLE

Control water. Control movement.

The two fundamental considerations were the route taken by rainwater and the movement of the lead sheet itself.

Falls were established so water could travel from the roof bays into the gutter system and then towards a dedicated sump outlet, reducing the potential for persistent ponding.

At the same time, bay sizes, wood roll joints and movement details were incorporated so the lead could expand and contract without concentrating stress into vulnerable junctions.

BS 6915 Leadwork →
The Lead Handbook →
Technical Guides →

Existing Covering

The original roof before removal and reconstruction of the leadwork system.

Renewed Leadwork

Code 5 bays, wood rolls and gutter details arranged around the lantern.

Completed Roof

A coordinated lead weathering and drainage system around the glazed lantern.

04 — DRAINAGE

Designing out standing water

Flat and low-pitched lead roofs depend heavily on the geometry beneath the sheet.

The substrate was configured to provide deliberate falls through the lead bays and gutter system towards the drainage point rather than relying on the covering alone to correct irregular levels.

A new sump outlet was incorporated so water entering the gutter had a clearly defined discharge point.

  • Falls formed within the substrate
  • Perimeter gutter system
  • Defined drainage route
  • New lead sump outlet
  • Lantern junctions kept clear of standing water

05 — THERMAL MOVEMENT

Breaking the roof into manageable sections

Lead expands and contracts continuously in response to changing temperature.

Rather than allowing one large sheet to absorb that movement, the roof was divided into appropriately sized bays using wood rolls, laps and separate gutter details.

Movement provisions were incorporated within the gutter system where required so longer runs could respond without transferring excessive stress to corners, welds or abutments.

LEAD WOOD ROLLS →
LEAD EXPANSION JOINTS →

06 — SIGNATURE DETAIL

The lantern junction

The glazed lantern creates the principal architectural feature of the orangery — and one of the most important weathering junctions.

The lantern interrupts the surrounding lead roof and introduces vertical upstands, corners and changes in material that all need to remain watertight while accommodating normal movement.

New lead was formed around the upstands and transitions, using flashings and welted cladding to create a continuous weathered interface between glazing, supporting construction and roof covering.

The detail has to work technically without visually overwhelming the lantern itself.

07 — PREPARATION + SUBSTRATE

Rebuilding the roof beneath the lead

  • Orangery glazing, masonry and adjacent finishes protected
  • Existing lead bays, gutters, flashings and outlets recorded
  • Surface debris and moss removed
  • Existing defective leadwork carefully stripped
  • Existing substrate exposed and inspected
  • Defective timber supports renewed where required
  • 18mm exterior-grade plywood decking installed where required
  • Stepped levels adjusted to establish the required roof geometry
  • Building paper / suitable separation layer installed
  • Falls established towards gutters and drainage points

08 — LEADWORK INSTALLATION

Installing the new Code 5 system

  • Code 5 perimeter gutter linings installed
  • Code 5 roof bays set out and formed
  • Wood roll joints incorporated between principal bays
  • Compatible clips and fixings used to secure the sheet
  • Code 5 cover flashings installed to walls and abutments
  • Welted lead cladding formed to lantern upstands
  • Movement details incorporated into longer gutter runs
  • Lead apron flashings formed at roof transitions
  • New sump outlet formed for controlled discharge
  • Corners and junctions bossed or welded where appropriate
  • Falls, outlets, flashings and welds checked on completion
  • Patination oil applied to exposed new leadwork

09 — MATERIALS

Materials used on the orangery

  • Code 5 rolled lead sheet
  • 18mm exterior-grade plywood
  • Timber core rolls
  • Building paper / lead underlay
  • Copper ringshank nails
  • Compatible leadwork clips and fixings
  • Lead-compatible sealant
  • Movement-joint components
  • Patination oil

CODE 5 LEAD →
18MM PLYWOOD →
BUILDING PAPER →
LEADWORK FIXINGS →

10 — SKILLS

More than laying sheet

  • Lead bossing
  • Lead welding
  • Lead dressing
  • Bay setting out
  • Wood roll formation
  • Gutter lining
  • Movement-joint detailing
  • Lantern upstand weathering
  • Sump outlet formation
  • Joinery and substrate preparation

The project demonstrates how specialist leadwork and supporting carpentry have to be considered together on fully supported lead roofs.

11 — PROJECT RECORD

Strip.
Re-form.
Re-cover.

The project imagery records the transition from the original lead roof to a renewed Code 5 system built around the existing glazed lantern.

The completed roof is visually simple, but beneath that simplicity is a carefully organised network of bays, rolls, gutters, flashings and drainage details.

12 — THE BUILDING

Vicarage House, Kirkby Wharfe

Vicarage House is a Grade II listed property in Kirkby Wharfe near Tadcaster, constructed using traditional materials including local stone and clay roof coverings.

The orangery sits within that historic context, and its glazed lantern and traditional lead roof create a transition between older architectural materials and a highly detailed weathering system.

The replacement leadwork therefore needed to improve performance without losing the restrained appearance appropriate to the property.

13 — TECHNICAL KNOWLEDGE

Understand the system behind the roof

Leadwork Standards →
The Lead Handbook →
Lead Roofing Guides →
Lead Sizing + Ordering Chart →
Lead Weight Calculator →

Bay size, support, fixing, drainage and movement must all be considered together if a lead roof is to perform as intended.

14 — WHAT THIS PROJECT SHOWS

Flat lead roofs are defined by what happens beneath the surface

The completed sheet is the visible part of the roof, but it cannot correct poor support, inadequate falls or inappropriate bay dimensions beneath it.

At Vicarage House, the replacement process allowed the whole roof geometry to be reconsidered before the new lead was installed.

That sequence — substrate first, drainage second, sheet layout third — is fundamental to the performance of fully supported lead roofing.

PROPERTY OWNER TAKEAWAYS

  • Ponding can indicate problems with roof geometry or drainage.
  • Lead should be divided into correctly sized sections.
  • Lantern junctions require carefully coordinated flashings.
  • Long gutter runs need adequate movement provision.
  • Drainage outlets should remain accessible and maintained.
  • The timber substrate is part of the lead roofing system.

15 — FREQUENTLY ASKED

Lead orangery roof questions

Why is standing water a problem on a lead roof?

Persistent ponding can indicate inadequate falls or drainage and places unnecessary demand on joints, corners and outlets. The supporting construction should be designed to encourage reliable discharge.

What lead code is used on an orangery roof?

The specification depends on the dimensions and design of the individual details. Code 5 was used throughout this project, but lead code should be selected for the particular bay, gutter or flashing rather than by roof type alone.

Why are wood rolls used?

Wood rolls form raised joints between separate lead bays, allowing the covering to be divided into manageable sheet sizes while providing a traditional detail.

Why are movement joints important in gutters?

Long lead-lined gutters experience thermal movement. Suitable movement detailing allows sections of the gutter to expand and contract without concentrating stress at fixed junctions.

Why was a sump outlet used?

A sump creates a defined low point at the drainage position, helping collect water from the gutter and direct it into the rainwater system.

THE LEAD LADS® / PROJECT ARCHIVE

Glazed lantern. Lead bays. Controlled drainage.

The Vicarage House orangery forms part of The Lead Lads® project archive documenting fully supported lead roofs, gutters, bays, flashings, canopies and complex architectural leadwork.

The project demonstrates why successful flat lead roofing depends on far more than the sheet itself — the substrate, falls, bay sizes, movement joints, lantern interfaces and drainage system all contribute to the finished roof.