Roofing Materials
208 sources in the library on roofing materials, 35 on this page cited in a published note. Each one says what the document covers and what it is good for. Name a source to see which document it is and where to read it. One at a time. Page 1 of 6.
- very strong RN-HXRMK1 cited
GOV.UK
The government's guidance on mandatory biodiversity net gain. It gives the 10 per cent objective and the dates from which the duty applies to major and non-major development.
Cited in Green Roofs & Living Roofs.
- very strong RN-II89LG cited
Health and Safety Executive
HSE states that almost one in five deaths in construction work involve roof work, with the main causes being falls from roof edges or openings and falls through fragile roofs and fragile rooflights. It requires all roofs to be treated as fragile until a competent person has confirmed otherwise, and calls for a working platform beneath the roof where possible, with stagings, guard rails, fall restraint, fall arrest and safety nets slung beneath and close to the roof. Sloping roofs need edge protection at the eaves, and on terraced properties to both front and rear; flat roofs need a secure double guardrail and toeboard around the edge. This is the citation for why a roof job needs scaffolding rather than a ladder.
Cited in The Complete UK Roofing Guide (2026).
- very strong RN-IU0X2M cited
Ministry of Housing, Communities and Local Government
The 2022 amendments took effect 1 October 2022 and extended the carbon monoxide alarm provisions. Table 2 sets the minimum flue sizes: 200mm diameter for a fireplace with an opening up to 500mm by 550mm, 125mm diameter for a closed appliance up to 20kW burning smokeless or Clean Air Act compliant fuel, 150mm for other closed appliances up to 30kW and 175mm for those above 30kW and up to 50kW. Diagram 17 gives the flue outlet clearances: at or within 600mm of the ridge the outlet must be at least 600mm above the ridge, elsewhere on a roof it must be at least 2300mm horizontally from the nearest weather surface and either 1000mm above the intersection or as high as the ridge, and it must be 1000mm above the top of any openable rooflight or dormer within 2300mm. Bends must be no more than 45 degrees to the vertical and paragraph 1.49 limits a sweepable flue to four changes of direction.
Cited in Boiler Replacement & Central Heating Costs (UK), Chimney Sweep Cost: 2026 UK Price Guide, Moving Boiler Cost: 2026 UK Price Guide, Splashbacks: Glass, Tile & Stone Options and 1 more.
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Ministry of Housing, Communities and Local Government
The 2026 edition takes effect on 24 March 2027 for work not connected with higher-risk building work, and 24 September 2027 where it is, with transitional arrangements in Circular Letter 01/2026. Table 3.1 sets limiting U-values for new dwellings: all roof types 0.16, wall 0.26, floor 0.18, window 1.6, rooflight 2.2, doors 1.6 W per square metre per kelvin, with air permeability 8.0 cubic metres per hour per square metre at 50Pa. Table 3.2 covers new elements in existing dwellings, that is extensions and loft conversions: roof 0.15, wall 0.18, floor 0.18, window 1.4 or Window Energy Rating Band B, rooflight 2.2. Table 3.3 covers upgrading existing elements: a roof with a U-value worse than the 0.35 threshold must be improved to 0.16, and note 2 confirms that for dormer windows the roof figure covers the roof parts and the wall figure the cheeks, while note 3 allows a higher U-value where the standard would limit head room provided the insulation plus air gap is at least the depth of the rafters.
Cited in Insulation: The Complete Guide.
- very strong RN-ISI2YI cited
Ministry of Housing, Communities and Local Government
2024 government hygrothermal modelling assessment of sprayed foam on domestic timber roofs, and an unusually quotable secondary source for BS 5250:2021's prescriptive roof guidance. Risks are low only where an OPEN CELL, moisture permeable insulant is used with an air and vapour control layer on the warm side and a space left between insulation and underlay, ventilated from the eaves where a high resistance underlay is used. For a WARM pitched roof with a high resistance underlay such as bitumen felt: each ventilated void should be at least 25 mm deep, ventilated at high and low level, plus a 15 mm allowance for underlay drape, giving 25 + 15 = 40 mm. For a low resistance underlay, option 1 is an AVCL plus an unventilated counter batten air gap for air permeable coverings; option 2, where an AVCL is impracticable, follows the HR guidance. It also states plainly that official moisture guidance is Approved Document C, that AD C was last fully revised in 2004 with 2010 and 2013 amendments, and that AD C REFERENCES THE 2002 EDITION OF BS 5250, not the current 2021 edition. It names BS EN ISO 13788:2012 (the Glaser method) as the calculation method referenced by the 2002 edition, and notes the Glaser method may underestimate risk because it cannot simulate heat and liquid transport, unlike BS EN 15026:2007.
Cited in Internal Wall Insulation: Costs & Methods, Roof Tiles & Slates: Coverage, Fixings & Ventilation.
- very strong RN-Z6AXUW cited
Ministry of Housing, Communities and Local Government (GOV.UK)
The full Approved Document A PDF, which carries the deemed-to-satisfy tables a domestic project is checked against. Section 2E covers foundations of plain concrete: paragraph 2E3 gives the recommended minimum widths of strip foundations in Table 10, keyed to ground type and total load of loadbearing walling per linear metre. Table 10 sets, for rock (not inferior to sandstone, limestone or firm chalk, requiring at least a pneumatic or mechanically operated pick to excavate), a width equal to the width of the wall at every load. For medium dense gravel or sand (requires a pick to excavate, a 50mm square wooden peg hard to drive beyond 150mm) and for stiff clay or stiff sandy clay (can be indented slightly by the thumb), the minimum widths are 250mm at 20 kN per linear metre, 300mm at 30, 400mm at 40, 500mm at 50, 600mm at 60 and 650mm at 70. Firm clay and firm sandy clay (thumb makes an impression easily) start at 300mm. The document also covers minimum depth of strip foundations, wall thickness rules for residential buildings up to three storeys (paragraph 2C10 covers internal loadbearing walls in brickwork or blockwork), buttressing, lateral support by floors and at roof level, interruption of lateral support, wall cladding in Section 3, and Section 5 on reducing sensitivity to disproportionate collapse with the building consequence classes.
Cited in Adding an Ensuite: Cost, Layout & Plumbing, Adding Porch, Annexe & Granny Flat: Cost, Planning & Rules, Bin & Bike Storage Ideas and 37 more.
- very strong RN-XGHWIW cited
Planning Portal
Explains the two loads a replacement roof has to deal with. For wind uplift the roof must be tied down to the structure with straps roughly 1.2m long fixed to the wall plate at every 2.0m centres. For spreading, it explains that ceiling joists fixed to the bottom of the rafters stop the rafters pushing the walls apart, and that a roof left exposed without ceiling joists needs an engineer's advice. The page states it is not a definitive source of legal information and refers readers to their local building control authority, so pair it with Approved Document A for the 15 per cent loading threshold.
Cited in The Complete UK Roofing Guide (2026).
- very strong RN-ITXSTK cited
Planning Portal
Explains that fitting a rooflight generally means cutting away part of one or more rafters or joists, so new support must be introduced, usually two pieces of timber fixed together spanning the new opening on either side. It directs the U-value limit to Approved Document L1 Volume 1, Table 4.2, and states that the room the rooflight serves must be ventilated, with the rooflight able to provide both rapid (purge) and background ventilation, and that ventilation of the roof void must also be considered.
Cited in Glazed Extensions: The Complete UK Guide, The Complete UK Roofing Guide (2026).
- very strong RN-5QRXP7 cited
The National Archives (legislation.gov.uk)
Class C permits any other alteration to the roof of a dwellinghouse, which is the right rooflight and Velux loft conversions rely on. Paragraph C.1(b) makes development not permitted if the alteration would protrude more than 0.15 metres beyond the plane of the roof slope, measured perpendicular to the original roof plane, and C.1(c) if the highest part of the alteration would be higher than the highest part of the original roof. C.1(d) excludes chimneys, flues, soil and vent pipes and solar equipment from the class, and condition C.2 requires any window in a roof slope forming a side elevation to be obscure-glazed and non-opening below 1.7 metres above the floor of the room.
Cited in Non-Habitable Loft Conversion: Loft Rooms & the Rules, Renovate or Rebuild? How to Decide, Roof Lanterns: Cost & Options, Roof Light vs Dormer Loft Conversion: Which to Choose and 6 more.
- very strong RN-M0RXVO cited
The National Archives (legislation.gov.uk)
Defines 'work at height' as (a) work in any place, including a place at or below ground level, and (b) obtaining access to or egress from such a place while at work, except by a staircase in a permanent workplace, where, if measures required by these Regulations were not taken, a person could fall a distance liable to cause personal injury. No minimum height is stated anywhere in the definition, which is the authority for killing the common '2 metre rule' claim in trade and garden-maintenance copy. Also defines fragile surface, personal fall protection system, working platform and suitable and sufficient.
Cited in Hedge Trimming Cost: 2026 UK Price Guide.
- strong RN-DFUI2F cited
British Board of Agrement
The document that settles what BS 5534's geographical wind zones are actually called. Table 3 is headed 'Zones of applicability according to BS 5534:2014, Clause A.8' and gives Zones 1 to 2 at a 345 mm batten gauge with battened lap, and Zones 1 to 5 at 250 mm battened lap, taped laps, integrated taped laps or with counter battens. They are NUMBERED 1 to 5, not lettered, so any note quoting a lettered exposure zone for roof fixings is wrong. Table 2 gives declared wind uplift resistances of 1119, 2165, greater than 1932, 2949 and 1932 Pa for those five conditions, and note (2) fixes the minimum design wind pressure for Zone 1 at 820 Pa. Validity is limited to a well sealed ceiling as defined in BS 9250:2007 clause 3.7, ridge height 15 m or less, pitch 12.5 to 70 degrees, site altitude 100 m or less and insignificant topography; otherwise uplift must be calculated from BS 5534. Counter batten allowance applies to any counter batten 11 mm deep or more, and NHBC does not accept wind zones based on counter battens on an unsupported roof. Also confirms BS 8000-6:2023 as the live workmanship code. Note the UKAS suspension of BBA accreditations from 26 Feb 2026 when weighing this source.
Cited in Roof Tiles & Slates: Coverage, Fixings & Ventilation.
- strong RN-DVFEWE cited
BSI
BS 5250:2021, published 31 July 2021, is the current code of practice for managing moisture in buildings and the reference for cold roof and warm roof condensation risk, roof void ventilation and the choice between high resistance and low resistance underlays. It replaced the earlier condensation code of practice and is the standard the NFRC and the Approved Documents point to when a note discusses interstitial condensation in a loft or a boarded roof.
Cited in Roof Tiles & Slates: Coverage, Fixings & Ventilation.
- strong RN-DQAH47 cited
BSI
Published 31 January 2018, this is the standard behind every dry ridge and dry verge claim. It applies to dry-fixed ridge and hip systems connected to timber ridge or hip battens, ridge boards or hip rafters, and to dry-fixed verge systems installed with slating or tiling, for both new buildings and renovations. It sets minimum performance requirements for fixing resistance, weather-tightness and durability with guidance on ventilation, and includes the performance tests, calculation methods and acceptance criteria. Cite it when a note says mortar bedded ridges have been superseded by mechanically fixed dry systems.
Cited in Roof Tiles & Slates: Coverage, Fixings & Ventilation.
- strong RN-QWYQ8T cited
BSI (British Standards Institution)
STATUS: CURRENT. BS 4978:2007+A2:2017 was published 30 November 2017 and is the live edition, superseding BS 4978:2007+A1:2011, BS 4978:2007 and the older BS 4978:1988 Specification for softwood grades for structural use. It specifies the methodology for visual strength grading of softwood for structural use and sets the permissible limits of characteristics (knots, slope of grain, fissures, wane, distortion, rate of growth) for two visual grades: GS (General Structural) and SS (Special Structural). These are grades, not strength classes: the strength class a graded piece maps to (C16, C24 and so on) depends on species and is assigned via BS EN 1912 and BS EN 338, so a note saying a timber is graded C24 to BS 4978 is conflating the two. The catalogue page confirms number, title, date, status and grades; the limit tables are paywalled.
Cited in Reclamation Yards & Salvage: Buying Reclaimed Materials, Roof Battens & Counter-Battens: Sizes & Grading, Structural Materials: The Complete Guide, Timber Merchants: What They Stock & How to Buy.
- strong RN-FCTWJD cited
BSI (British Standards Institution)
STATUS: CURRENT. BS 5534:2014+A2:2018 published 28 February 2018. Full title is 'Slating and tiling for pitched roofs and vertical cladding. Code of practice' - NOT the older 2003 title 'Code of practice for slating and tiling', which is a common stale citation. Gives recommendations primarily for the design, performance and installation of new build pitched roofs including vertical cladding, and for normal re-roofing work including repairs, using slates, tiles, shingles and shakes and their associated components. The A2:2018 amendment reworked wind loads and uplift resistances of the roof covering and underlay around the Eurocodes and withdrew reliance on the tensile strength of mortar bedding to resist wind uplift, which is why mortar-bedded ridges and verges alone no longer satisfy the code. Batten grading rules sit inside this standard (clause 4.11 and its annex), not in BS 4978, BS 5756 or BS EN 14081.
Cited in Builders' Merchants Explained: How They Work & How to Buy, Natural Slate vs Fibre-Cement Slate, Roof Battens & Counter-Battens: Sizes & Grading, Roof Replacement: Signs You Need One & What's Involved and 7 more.
- strong RN-1YSDSK cited
BSI (British Standards Institution)
STATUS: CURRENT. BS 8417:2024 published 15 August 2024, superseding BS 8417:2011+A1:2014. Gives recommendations and guidance for the preservative treatment of wood to provide protection against biodeterioration in end-use situations. Covers solid wood and glued laminated wood (Glulam); excludes wood-based panel products, physically or biologically modified wood, and curative treatments. It takes into account the natural durability and treatability of the wood, the use class as defined in BS EN 335, and the desired service life, and recommends penetration and retention levels for different timber components. This is the source of the Use Class 2 / Use Class 4 language on treated batten and fence post labelling, and of the stated desired service lives (30 or 60 years) manufacturers quote. Treatment certificates quoting BS 8417:2011 predate the 2024 rewrite.
Cited in Fencing Cost & Types: A UK Guide, Padstones, Bearings & Wall Plates Explained, Roof Battens & Counter-Battens: Sizes & Grading, Timber Cladding: Species, Treatment & Cost.
- strong RN-2FH5S1 cited
BSI (British Standards Institution)
STATUS: CURRENT. BS EN 13956:2012 was published 31 January 2013, is identical to EN 13956:2012 and supersedes BS EN 13956:2005. It gives the definitions and characteristics for plastic and rubber sheets used for roof waterproofing, specifying the requirements and test methods and providing for evaluation of conformity, with thermoplastic rubber blends and alloys covered and typical materials and applications set out in Annex E. This is the harmonised product standard behind single ply flat roof membranes such as EPDM, TPO and PVC, so it is what a note should cite when it says a single ply membrane is CE or UKCA marked, as distinct from BS EN 13707 for reinforced bitumen membranes and BS 6229 for the design of flat roofs with continuously supported coverings. Catalogue page confirms number, title, date, status and scope; the characteristic tables are paywalled.
Cited in Flat Roof Materials: EPDM vs GRP vs Felt.
- strong RN-TXD8LA cited
BSI (British Standards Institution)
STATUS: CURRENT, and it is the replacement for the withdrawn BS EN 519. BS EN 14081-1:2016+A1:2019 was published 31 August 2019, ISBN 978 0 539 06 228 1, and supersedes BS EN 14081-1:2016. It sets the requirements for strength graded structural timber of rectangular cross section produced by sawing, planing or similar, covering BOTH visually and machine graded timber, and it gives the test methods, the Assessment and Verification of Constancy of Performance and the marking rules, which is what makes a C16 or C24 stamp on a joist meaningful. It excludes fire retardant treated timber, thermally or chemically modified timber and structural finger jointed timber. Parts 2 and 3 add machine grading type testing and factory production control. Cite this with BS 4978 (visual grading rules), BS EN 338 (strength classes) and BS EN 1912 (assignment of grade and species to class). Catalogue page confirms number, title, date, status, supersession and scope.
Cited in Builders' Merchant vs DIY Store: Which Is Cheaper?, Reclamation Yards & Salvage: Buying Reclaimed Materials, Suspended Timber Floors: Joists, Boards & Ventilation, Timber Merchants: What They Stock & How to Buy.
- strong RN-JXXFKF cited
BSI (British Standards Institution)
STATUS: CURRENT. BS EN 492:2012+A2:2018 was published 30 June 2018 and supersedes BS EN 492:2012+A1:2016 and BS EN 492:2012. It sets the technical requirements and test methods for fibre cement slates and fittings used for roofing and for internal and external wall and ceiling finishes, applying to slates with a maximum height dimension of 850 mm and covering products reinforced with various fibre types. It specifies nominal dimensions, shapes and edge configurations and gives test methods for density, mechanical properties and water resistance (impermeability). Importantly for a note, it does NOT cover installation technique, design or wind uplift calculation: those sit in BS 5534, so a note should not cite BS EN 492 for fixing patterns. Catalogue page confirms number, title, date, status and scope; the requirement tables are paywalled.
Cited in Natural Slate vs Fibre-Cement Slate.
- strong RN-BI7QQG cited
BSI (British Standards Institution)
STATUS: CURRENT. BS EN ISO 12543-2:2021 was published 28 February 2022 and is identical to ISO 12543-2 and EN ISO 12543-2; it supersedes BS EN ISO 12543-2:2011. It sets the performance requirements for laminated safety glass as defined in ISO 12543-1, covering impact behaviour, durability against humidity, high temperature and solar radiation, fire performance, appearance and dimensional specification. This is the part to cite for laminated safety glass, which matters for rooflights and overhead glazing where laminate is required so that a broken pane is retained by the interlayer rather than falling; toughened glass to BS EN 12150-1 fragments instead. The series has six parts: -1 definitions and component parts, -2 laminated safety glass, -3 laminated glass, -4 test methods for durability, -5 dimensions and edge finishing, -6 appearance. Catalogue page confirms number, title, date, status and scope; the requirements are paywalled.
- strong RN-3B3DX9 cited
BSI (British Standards Institution)
STATUS: CURRENT, and it is the replacement for a standard the notes still cite. BS EN ISO 16535:2019 was published 31 July 2019 and expressly supersedes BS EN 12087:2013, which is WITHDRAWN. It specifies the equipment and procedure for determining the long term water absorption of thermal insulating products, giving two methods: method 1 partial immersion and method 2 total immersion. This is the test behind the WL(T) declared value used to compare rigid boards for below ground, inverted roof and perimeter use, which is why extruded polystyrene (XPS) is specified below damp proof level rather than expanded polystyrene or unfaced PIR. Any note citing BS EN 12087 for water absorption of insulation should be corrected to BS EN ISO 16535. Catalogue page confirms number, title, date, status, the supersession of BS EN 12087:2013 and the two methods; the procedure detail is paywalled.
Cited in EPS vs XPS Insulation: Which & Where.
- strong RN-37TLPF cited
HETAS
HETAS consumer advice on sweeping frequency. States the chimney should be swept at least twice a year when burning wood and at least once a year when burning smokeless fuels, and that the best times are just before the start of the heating season and after the stove has been out of use for a prolonged period; where sweeping twice, the second sweep should follow the peak of the main heating season. Frequency also depends on how heavily the appliance is used. This is the only citable tier 2 statement of UK sweeping intervals; the commonly quoted Guild of Master Chimney Sweeps table is not from a body on the permitted source tiers.
Cited in Chimney Sweep Cost: 2026 UK Price Guide.
- strong RN-GSDAA1 cited
NHBC
August 2022, first issue, one page. NHBC performance standard 7.2.15 requires roofs to have adequate precautions against condensation. Section 12.4.3.2 of BS 5250 gives the method for deciding whether a roof covering is air permeable: the covering is deemed air permeable if the airflow at a differential of 10 Pa exceeds 17.4 m3/h Ar, where Ar is the tested area of the outer weatherproof covering in m2 as defined in BS 5534:2014+A2:2018; below that it is air impermeable. Where air impermeable coverings are used on a COLD pitched roof with an LR underlay, provide ventilation openings to the roof void per BS 5250 sections 12.5, 12.6 and 12.7, plus ventilation openings to the batten space above the underlay created with minimum 25 mm deep counter battens, free area not less than 25,000 mm2/m at eaves level and 5,000 mm2/m at ridge level. The same batten-space figures apply on a WARM pitched roof with an LR underlay, with an air and vapour control layer at ceiling level. This is the cleanest in-tier statement of the 25,000 and 5,000 mm2/m opening figures, i.e. 25 mm continuous at eaves and 5 mm at ridge. The live URL 403s to plain scripted fetches on some paths but answers 200 with a browser user agent; the Wayback copy reads cleanly.
Cited in Roof Tiles & Slates: Coverage, Fixings & Ventilation.
- strong RN-BNGAID cited
United Kingdom Accreditation Service
The live UKAS register of accredited bodies currently under sanction. It records the British Board of Agrement under imposed suspension from 26 February 2026 across all four of its accreditations: ISO/IEC 17065 product certification and ISO/IEC 17021 management systems under reference 0113, ISO/IEC 17020 inspection under 4345, and ISO/IEC 17025 testing under 0357. This is the page to check before repeating any advice that treats a BBA certificate as accredited third party assurance.
Cited in Breathable Membranes for Roofs & Walls, Brick Slips & Brick Cladding Systems, Cavity Wall Insulation Materials Compared, Damp Proof Membranes (DPM) & DPC: Types & Installation and 7 more.
- good RN-J8WBI4 cited
Lead Sheet Training Academy
The LSTA is the UK training body for lead and hard metal roofing, operating from a purpose-built facility at East Peckham in Kent and recognised as a CITB Approved Training Organisation. It publishes Rolled Lead Sheet: The Complete Manual, the standard reference for lead sheet codes, fixing centres and detailing at chimneys, valleys and abutments. It is the correct authority for a lead flashing note, and its training status is the credential to look for in a leadworker.
Cited in The Complete UK Roofing Guide (2026).
- good RN-616CAH cited
National Federation of Roofing Contractors
NFRC guidance sheet MRK111 v2.0, March 2021, and the best free tier-3 source on battens. Rafters at a maximum spacing of 600 mm centres. Battens conforming to BS 5534 arrive pre-graded, so on-site grading is no longer needed; every batten is stamped with supplier details, size, origin (imported or British grown and/or species code), 'Graded BS 5534' and independent third-party accreditation. Permitted species: British-grown larch (WLAD), British pine (WPNN), British spruce (WPCS); imported redwood (PNSY), whitewood (WPCA), spruce-pine-fir (WPCE), southern pine (WPNE). COUNTER BATTENS DO NOT NEED TO BE GRADED provided they are fully supported and fit for purpose. No section of batten should be under 1.2 m or fixed at fewer than three points to the rafters. Nails 3.35 mm diameter, typically 65 mm long, but a fixing calculation is required as wind loading may change nail type and size. Joints square sawn and butted onto the centre of a rafter. Truss rafter roofs: gauge over 200 mm, no more than one joint on the same support in any four consecutive courses; gauge under 200 mm, no more than three joints in any twelve. Cut ends at verges treated with preservative where they meet bedded mortar. The HSE only approves BS 5534 graded battens as a secure foothold.
- good RN-0NJ8CN cited
National Federation of Roofing Contractors
The roofing trade body's own index of the standards that govern UK roofing work, useful for checking which standard a note should name. It lists BS 5250:2021 management of moisture in buildings, BS 5534:2014+A2:2018 slating and tiling for pitched roofs and vertical cladding, BS 6229:2018 flat roofs with continuously supported flexible waterproof coverings, BS 8612:2018 dry fixed ridge, hip and verge systems, BS 8000-6:2013 slating and tiling workmanship, BS 8217:2005 reinforced bitumen membranes, BS 8218:1998 mastic asphalt roofing, BS 5427:2016+A1:2017 profiled sheet cladding and BS 8414-1 and 2:2020 fire performance of external cladding, alongside Approved Documents A, B, H and L.
Cited in The Complete UK Roofing Guide (2026).
- supplier figure RN-KLAX7C cited
JJ Roofing Supplies
the retail price JJ Roofing Supplies publishes for Velux GGL Centre Pivot Pine Roof Window, which is the supply figure the cost book records for this item
- supplier figure RN-NAR50C cited
Lawsons (Whetstone) Ltd
the retail price Lawsons (Whetstone) Ltd publishes for Damp Proof Membrane DPM, which is the supply figure the cost book records for this item
Cited in Damp Proof Membranes (DPM) & DPC: Types & Installation.
- supplier figure RN-ZAETTP cited
Marley
Marley's technical note on laying its concrete tiles at low pitch. It gives the minimum rated pitch for each of its interlocking tiles and explains what a roof below the recommended pitch needs instead.
Cited in Clay vs Concrete Roof Tiles: Cost, Lifespan & Looks.
- supplier figure RN-F2JJQY cited
Marley Ltd
JB Red roofing batten: available in 25 x 38mm and 25 x 50mm sections only, factory graded in the UK to BS 5534 using laser (Goldeneye) scanning, and described as the only UK factory-graded roof batten holding BBA certification. Produced from slow-grown kiln-dried sideboards. Treated with MicroPro preservative complying with BS 8417:2011 Use Class 2, carrying a 60-year desired service life.
- supplier figure RN-5V4C8V cited
The Lead Lads
a lead roofing merchant's own guide to what milled lead sheet costs per kilogram, and how the price moves with the LME lead price, which is the basis on which lead flashing and sheet are sold by weight rather than by the piece
Cited in Lead Flashing & Alternatives Explained.
- supplier figure RN-HF2FVE cited
VELUX
The manufacturer's own size code table, the only reliable source for what a Velux code means. Pitched roof window codes and dimensions include FK06 at 66cm by 118cm, MK04 at 78cm by 98cm, MK06 at 78cm by 118cm, MK08 at 78cm by 140cm, PK06 at 94cm by 118cm, PK08 at 94cm by 140cm, SK06 at 114cm by 118cm, SK08 at 114cm by 140cm, UK04 at 134cm by 98cm and UK08 at 134cm by 140cm. Flat roof window sizes run from 60cm by 60cm up to 150cm by 150cm and 200cm by 100cm. The first letter pair gives the width band and the digits the height, which is the pattern a size-code note should explain.
Cited in Loft Conversion Windows & Skylights: Complete Guide, Roof Window Sizes Explained (Velux Codes).
- supplier figure RN-G68MSX cited
Welsh Slate Ltd
Welsh Slate batten gauge, batten quantity and holing gauge by slate length. At 50mm headlap: 600mm slate, batten gauge 275mm, 3.64 lin m batten per m2, holing gauge 335mm; 550mm slate 250mm gauge, 4.00 lin m/m2, holing 310mm; 500mm 225mm gauge, 4.44 lin m/m2, holing 285mm; 455mm 202mm gauge, 4.95 lin m/m2, holing 262mm; 400mm 175mm gauge, 5.71 lin m/m2, holing 235mm; 350mm 150mm gauge, 6.67 lin m/m2, holing 210mm; 300mm 125mm gauge, 8.00 lin m/m2, holing 185mm. At 80mm headlap the gauges tighten: 600mm slate 260mm gauge and 3.85 lin m/m2 (holing 350mm), 500mm 210mm gauge and 4.76 lin m/m2 (holing 300mm), 400mm 160mm gauge and 6.25 lin m/m2 (holing 250mm), 300mm 110mm gauge and 9.09 lin m/m2 (holing 200mm).
- supplier figure RN-BVWJKY cited
Wickes
the retail price Wickes publishes for Restec 2020 Flexitec GRP Roofing Kit 10m2, which is the supply figure the cost book records for this item
- very strong RN-8Y875H
Ministry of Housing, Communities and Local Government
The list of test standards common across product families that UK approved bodies use when assessing construction products, published 27 January 2021 and last updated 21 May 2025, in force from 1 January 2021. Names the specific test methods behind fire performance claims a product data sheet will quote, so a note can verify what a rating actually measures: TS 1187 external fire exposure to roofs; EN ISO 1182 non-combustibility test; EN ISO 1716 gross heat of combustion or calorific value; EN 13823 the single burning item test for building products excluding floorings; EN ISO 11925-2 ignitability under direct flame impingement, the single-flame source test; EN ISO 9239-1 burning behaviour of floorings using a radiant heat source; EN 1365-3 and EN 1365-4 fire resistance of loadbearing beams and columns; EN 1634-1 and EN 1634-3 fire resistance and smoke control for door and shutter assemblies and openable windows; and the EN and ENV 13381 series for applied protection to composite, hollow steel, timber and steel structural members. The latest versions of the standards themselves are on the BSI website.
- very strong RN-XS4MR0
Ministry of Housing, Communities and Local Government and Office for Product Safety and Standards
The official list that decides which British and European standards a construction product's declaration of performance must be assessed against, first published 18 December 2020 and last updated 26 September 2025, applying to England, Scotland and Wales. Explains that designated standards support Regulation (EU) No. 305/2011 as amended from time to time, and that together with the horizontal standards on assessment methods they create the common technical language UK approved bodies use when carrying out assessments. Published as a notice of publication dated 26 September 2025, a 51 page PDF, superseding the notice of 1 January 2021 of 53 pages, alongside a consolidated list in ODS format at version 2. This is the reference that turns the standard number cited in a declaration of performance into a check that the right standard was used. A companion page covers horizontal test specifications for construction products.
- very strong RN-3X8KRH
Planning Portal
The Planning Portal's consumer-facing statement of the Class C roof alteration rules: an alteration must not project more than 150 millimetres from the plane of the existing roof slope, and a window in a roof slope forming a side elevation must be obscure-glazed and, if opening, sited 1.7 metres above the floor of the room. Useful as the plain-English citation to sit alongside the GPDO itself; it refers readers to the government's householder technical guidance for the rest.
- strong RN-04DH6J
BBA (British Board of Agrement)
The certification body whose Agrement Certificate is what a note usually means when it says a system is approved, and the page that lists which schemes it actually runs. The BBA's certification team issues certificates for the BBA Agrement, HAPAS (Highways Authority Product Approval Services), European Technical Assessment (ETA), and the Microgeneration Certification Scheme. Alongside product certification it runs certification of people, including the BBA Approved Installer Scheme, the BBA Competent Person Scheme, the BBA Gas Membrane Approved Installer Scheme, TrustMark registration and the BBA PAS 2030 Scheme, plus a Client Managed Inspection Service. Its testing services are also available standalone and include durability, mechanical, physical and structural, weather resistance and wind serviceability, conformance and fit-for-purpose, thermal performance, and onsite testing and trials. An Agrement Certificate is the route by which a product without a harmonised European product standard, such as a tanking membrane, a multifoil or a proprietary EWI system, gets an independently assessed statement of fitness for a stated use.
- strong RN-J699CC
BSI (British Standards Institution)
STATUS: CURRENT. BS 1202-1:2002 was published 7 February 2002 under committee B/518, ISBN 0 580 37316 9, and specifies the requirements, including dimensions and finish, for steel nails. It divides them into wire nails, of which it lists 14 types from convex head roofing nails to duplex head nails with round, square, annular ringed and helical threaded shanks and chisel or diamond points, and cut nails, of which it lists two types, cut clasp nails and cut floor brads. This is the standard behind a specification such as galvanised round wire nails to BS 1202-1, and it is the reference used when BS 5534 calls up nail types for tile and slate fixing. Parts 2 and 3 (both 1974) cover copper nails and aluminium nails. Catalogue page confirms number, title, date, status, committee and the type lists; dimensional tables are paywalled.