A dormer is an additional windowed structure that is built into the roof of a house. Notwithstanding sheltered location on a roof area, lead sheet is not recommended for use as clips to secure free edges owing to its low mechanical strength, relative to alternative metals. Code 7 lead would normally be reserved for use on churches or stately homes for example. Sub deck, usually 18mm plywood or rough sawn timber. Insulaiton, above the vapour control layer, Insulaiton should be of the required thickness. Further, nailing patters should be limited to the head of each panel and not extend to the maximum widget of the panel. Metals that can be used with lead include copper, stainless steel, zinc and aluminium. 5 Lay lead soaker flashing with 300 mm felt undefiay to the upstand (Lead flashing to be fitted under bottom edge of dormer and then cathed over roof slates to allow to run offi Attach lead apron to sill support timber & ply (dressed over tilting fillet) Fix dormer in place using metal fixing plates (supplied) Minimum of 6No screws used on Sometimes, alternatives to lead flashing are necessary due to its negative environmental impacts. Widely used in conjunction with a range of roofing materials from slates to tiles, lead cladding panels seldom look out of place. We will explore the material, its uses, the application of lead and compare this to examples of our work over time. There are two ways to support the cheeks; one way involves doubling up the rafters and bolting them together before constructing the cheek walls off of these rafters. If you would like to change your settings or withdraw consent at any time, the link to do so is in our privacy policy accessible from our home page.. In line wood rolls, bossed to form a finish. Send your requirements via email. The Lead Lads are well versed in providing lead cladding panels to any dormer.. it is not usual to fix lead sheet covering directly on top of rigid Insulaiton boards for example. Some of our partners may process your data as a part of their legitimate business interest without asking for consent. Additionally, proper insulation should be installed around windows and door frames to keep hot air out during summer months and warm air in during winter months. The addition of this dormer to any home can bring about increased visual interest as well as additional space for various uses such as bedrooms, bathrooms or even storage areas. Coat the lead before turning up clips around the edges. Technical Training - Pitched roof coverings 1. Apply the oil to all newly installed lead items - large or small. Code 7 lead would be identified by a white label. Do dormer cheeks need to be ventilated? Send your requirements via email. Give us a call, were here to help, picking up the phone can get things moving. Lead sheet is a soft and malleable metal which means it's an excellent roofing material because it can be formed and shaped to suit any detail. >> Further, code 5 lead can be identified by a red label. Kooltherm - Rigid Phenolic Insulation. Alternatives to lead clips are copper, 0.6mm thick and 50mm wide, or stainless steel, 0.7mm thick and 50 mm wide. Snow, wind, water, are all in addition to the weight of the lead. Importantly, the thickness of a given code of lead sheet should not reduce by more than 25% when bossed. Further, copper can be used to clip other no exposed areas such as welts, seams and rolls. Please note, some of the imagery in this section is courtesy of The LSTA: Arguably, the substrate is as important as the roof covering itself. Aluminium clips should not be used in such environments due to the potential of corrosion being caused by sodium chloride which will attach the surface of the aluminium. These are intended to break up the lengths of lead sheet used to ensure that thermal expansion is within guidelines for individual pieces of lead. Clips or tabs are an important aspect when it comes to securing rolled lead sheet. Usually made from a modified bitumen, an alternative to traditional lead flashing is designed with a metal grid at its core. of 18mm thick. When installing a lead roof covering, making provision for a warm or vented roof is critical. The surface should allow the lead to move freely with temperature changes without abrasion to the underside of the lead sheet. /Subtype /XML A substrate to form a dormer cheek should be correctly formed using quality plywood at least 15mm thick. /Outlines 6 0 R endobj Stainless stel insect mesh. In contrast however, if the material is returned back on itself, greater strength can be achieved and a reduction in width may then be acceptable. A number of details exist when using lead for dormers. Photo 1: Remove shingles and sheathing board. Often, owing to the thickness, code 3 lead is used for soakers which are interleaved between slates. Heres why you should use it when installing lead sheet and lead details. Flashing functions as a barrier between the elements and your home by keeping moisture away from vulnerable areas such as window and door frames, wall/roof intersections, chimneys, skylights, or any other openings. The British standard for lead as a material isBS EN 12588. This will ensure maximum comfort whilst also helping protect against any future problems caused by condensation build up. Looking for a free quote? Lead ridge detail with clips in stainless steel, lead or copper. Alternatively, cheeks can be constructed on separate posts that have been built in to provide additional support to both sides of the dormer. It typically consists of thin strips of metal that are installed around these locations before being sealed with caulk or tar for additional protection. A Leadworker should have an ability to think outside the box to hone their craft. Each course is short duration and extremely focused on a particular discipline. Are you a trade or supplier? Chimney flashings to a stack or masonry roof penetration. We usually end up referring clients to the 75mm lap diagram that we show in the manual. AutoCAD LT 2017 - English 2017 (21.0s (LMS Tech)) At the end of the course, candidates are expected to be proficient in the theory and practice of working with rolled led sheet. If you're looking for a way to add more space to your home, constructing a dormer can be a great solution. Anneales stainless steel conforming to BS EN 10088 at least 50mmin width and not less than 0.375mm in thickness. leadworkers often add heat using a small gas power blow torch to make the process of bossing easier. For those familiar with architecture, a dog-house dormer is easily recognizable. This provides the same rigid yet malleable characteristics that traditional lead flashing offers, but without the damaging effects on both human and animal life. That means the decking which supports the lead sheet should have a minimum of a 50mm through ventilated void underneath the decking and the ventilated pathway should have no stagnant air pockets. Bossing stick | A time served piece of equipment for bossing rolled lead sheet around timber forms. Our number one priority has always been customer service. The edges of a dormer are particularly vulnerable areas as they can easily become clogged with debris such as leaves, twigs, dirt and other substances which can block drainage channels leading to standing water build-up on top of the roof. Airtrak CV Cheek Ventilator . Is standard bracing acceptable? The Building Control Office should be consulted for guidance. Apply the oil before any rain and at the end of the day's work. Code 3 lead has a thickness of 1.32mm and a weight of 14.97 kg/m2. Code 6 lead is used for applications where there may be greater exposure or further longevity is required. The main parts that form a dormer are the roof, side walls (cheeks) and front wall which faces the garden. xZF|i91N1Z=}U2hMU]r}[am3*=_N9x7,6{}:q~q~}8MGs3^V?OOjE8 q'q]uT:XJ)s])|+[gTyz|$5b0y}^E?r~SfW>
soe3ftg1^L3. Always ensure that sufficient additional width is allowed to create details such as splash laps. PDF-XChange Viewer [Version: 2.0 (Build 42.7) (Oct 27 2009; 19:37:40)] Nails for Leadwork should be large headed copper or stainless steel and confirm to BS 1202-1 &2. But because they are raised, they create a potential entry point for embers and sparks during a wildfire. Timber Framing. Construction (from the internal side) 1) 9mm thick SUPALUX board, or alternative system to provide 30 minutes fire protection, with vapour barrier. This is because there is a layer of asphalt adhesive applied to this side which helps prevent water vapor from making its way through. >> The bitumen provides a look similar to real lead whilst still being incredibly easy to manipulate and shape during installation. << Weathering details and fixings, 2.1 The Standards and Technical Requirements, 3.2.6 Rendering, plastering and screeding, 3.3 Timber preservation (natural solid timber), 4.1 Land quality managing ground conditions, 4.1.2 Initial Assessment desk study (all sites), 4.1.3 Initial Assessment walkover survey (all sites), 4.1.5 Basic Investigation (sites where hazards are not identified or suspected), 4.1.6 Detailed Investigation (sites where hazards are identified or suspected), 4.1.7 Managing the risks (sites where hazards are found), 4.2.4 The effects of trees on shrinkable soils, 4.2.8 Design and construction of foundations in shrinkable soils, 4.2.9 Foundation depths for specific conditions in shrinkable soils, 4.3.8 Sloping ground and stepped foundations, 4.4 Raft, pile, pier and beam foundations, 4.5 Vibratory ground improvement techniques, 4.5.4 Confirmation of suitability for treatment, 4.5.6 Compatibility of the ground, design and treatment, 4.5.12 Verification of completed treatment, 5 Substructure, Ground Floors, Drainage and Basements, 5.1 Substructure and ground-bearing floors, 5.1.18 Laying the ground-bearing floor slab, 5.2.7 Construction of suspended concrete ground floors, 5.2.9 Thermal insulation and cold bridging, 5.3.7 Design to avoid damage and blockages, 5.4 Waterproofing of basements and other below ground structures, 6.1.18 Wall ties and bed joint reinforcements, 6.1.20 Protection of the works during construction, 6.3.3 Supporting load-bearing internal walls, 6.3.8 Partitions: internal non load-bearing, 6.3.10 Construction of steel framed partitions, 6.3.11 Construction of proprietary systems, 6.4.6 In-situ concrete floors and concreting, 6.4.11 Joists supported by intermediate walls, 6.4.20 Floating floors or floors between homes, 6.6.12 Staircases made from timber and wood-based products, 6.8.3 Solid fuel fireplaces and hearths, 6.9.11 Electrical continuity and earth bonding, 6.9.19 Insulated render and brick slip cladding, 6.10.4 Structural design of load-bearing floors and walls, 6.10.10 Construction of load-bearing walls and external infill walls, 6.10.12 Fixing floor decking and ceilings, 6.10.20 Cladding, lining and sheathing boards, 7.1.3 Flat roof, terrace and balcony general design, 7.1.5 Flat roof, terrace and balcony structural design, 7.1.8 Profiled self-supporting metal decks, 7.1.9 Profiled self-supporting metal roofing, 7.1.10 Thermal insulation and vapour control, 7.1.11 Waterproofing layer and surface treatments, 7.1.12 Green and biodiverse (brown roofs) including roof gardens, 7.1.16 Accessible thresholds and upstands, 7.1.17 Parapets and guarding to terraces and balconies, 7.2.10 Strutting for attic trusses and cut roofs that form a floor, 7.2.15 Ventilation, vapour control and insulation, 8.1.7 Electrical services and installations, 8.2.11 Electrical installation requirements, 8.2.12 Pipes, insulation and protection from cold, 8.3 Mechanical ventilation with heat recovery, 9.1.7 Ceramic, concrete, terrazzo and similar tile finishes, 9.3.5 Ceramic, concrete, terrazzo and similar tile finishes, 9.4.3 General provisions cupboards and fitments, 9.4.6 Airing cupboards, cupboards, worktops and fitments, 9.4.7 Ironmongery, prefabricated items and other materials, 9.5.4 Conditions for painting and decorating, 10.1.10 Permanent prefabricated garages and carports, 10.2.4 Freestanding walls and retaining structures, 10.2.8 Garden areas within 3m of the home, construction should be in accordance with the design, cheek studs should be supported by either a double rafter or a double oor joist, where cheek frames do not extend to oor level, two fixed rafters should be used to provide the necessary support, trimming members should be large enough to support additional loads from the main roof members, dormer framing and cladding, a suitable lintel should be provided over the opening. Like many trades, there is little substitute for experience. The structure of the dormer consists of three parts: the roof, two side walls known as "cheeks", and a front wall facing out towards the garden. /Type /Metadata Copper ringshank nails, 25mm x 3.35mm should be used to secure all leadwork, dormer cheeks are no exception. Generally constructed from timber, these walls are supported in one of two ways: either by doubling up the rafters and bolting them together as supports for the cheeks, or by installing purpose-made steel brackets between each pair of rafters. The are used to separate lead panels to facilitate thermal movement. Book yours now >>>. Full scale training rigs are available and students will carry out the practical installation of lead as part of the course. Traditionally gutters of this type incorporate steps or drips in the design. Your email address will not be published. Designed for applicants who want to undertake heritage roofing projects, three courses are offered in lead. At 3.15mm thick and with a weight per m2 of 35.72kg code 7 rolled lead sheet, when installed correctly, will offer an extremely long lasting roof covering. In line wood rolls which are cut and welded. Stainless steel clips will be provide a contrast to the leadwork itself. endobj The fixing of lead sheet is carried out in many different ways, all of which are dependent on the particular application. If exterior grade plywood or blockboard is used a building paper to BS1521 Class A should be used. >> Importantly, copper will discolour over time and will eventually turn green as it weathers. This brief guide aims to provide insight into how dormer cheeks should be fitted. Used to secure a lead ridge capping and installed at 300mm centres. However, it is important to follow the basic principles of sizing and fixings as indicated in the Rolled Lead Sheet Manual to reduce the effects of fatigue cracking or creep. Interestingly, the melting point of lead is 327.4C. Some do not like the aesthetic of this but such clips are extremely effective in the prevention of wind uplift on an edge that would be otherwise unsecured. Importantly, as with all leadwork, they should be installed in accordance with BS6915:2001+A1:2014. The type of material used to construct the sidewalls is also important; if wood is used as an option it should conform to local codes and regulations regarding fire safety and other considerations. Lead sheet is a soft and malleable metal which means its an excellent roofing material because it can be formed and shaped to suit any detail. The curved timber moulding performs two functions: - creates a drip for the curved roof to ensure water runoff is thrown clear of cheek - provides weathering to our copper ring shank head-fixings which secure the cheek cladding Vertical welted cladding, Sandgate. However, while increased functionality is certainly beneficial, there are aesthetic considerations that must be taken into account as well; large dormers may require a steel ridge beam in order to support the upper part of the roof structure which could detract from the overall appearance of your building's exterior. << If youre looking for an alternative to traditional lead flashing, many options exist. Not only can this help reduce moisture levels and dampness in your home but it also ensures that any issues with moisture infiltration will be prevented before they become an issue. Commonly, alternative metals are used as clips. There are two ways to support the cheeks; one way involves doubling up the rafters and bolting them together before constructing the cheek walls off of these rafters. As important as the leadwork is the substrate below. Lead dormers are an important part of lead roofing applications. 2017-02-10T11:09:32Z Approved by CITB, they offer a recognised qualification for applicants to further develop their learning on site. Commonly, lead dormer cheeks are formed using 600mm code 5 lead. Unlike the wall of a typical structure, these walls do not support any load and therefore there is no need for additional framing. Importantly, the timber used should be well seasoned and provided maximum resistance to shrinkage and warping. /PageMode /UseOutlines Stone | Building paper underlay to BS 1521. Installing lead incorrectly, is simply a waste of time, materials and money. >> For a better experience, please enable JavaScript in your browser before proceeding. Lead Dormer Corners are preformed they are as quick to fit as a slate or tile. Attention to detail is paramount when it comes to completing proper and compliant lead sheet installation. Especially when it comes to refurbishment of existing roof areas or structures. Apron flashings when using profiled tiles. >> Not only this, but having a dormer installed also provides extra living space within your home and improves its overall aesthetic too. To protect against this risk, dormer vents should be built from fire-resistant materials such as metal or ceramic tile. Code 4 lead has a thickness of 1.80mm and a weight of 20.41 kg/m2.