Floors & Screeds
182 sources in the library on floors & screeds, 22 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 5.
- very strong RN-2IWEP7 cited
Health and Safety Executive
HSE's guidance note behind every slip-resistance figure a flooring or paving note quotes, and the source that separates the two tests people conflate. Table 1 classifies slip potential from pendulum test values (PTV): 0 to 24 high, 25 to 35 moderate, 36 and above low. Table 2 gives the parallel Rz microroughness classification. It describes the HSL/UKSRG ramp CoF test, then deals with the German ramp tests separately: DIN 51097 uses barefoot operators with a soap solution and DIN 51130 uses heavily cleated EN ISO 20345 safety boots with motor oil, and HSE states it has reservations about both because neither uses contaminants representative of real workplaces and the way results are reported is a cause for concern. Table 3 sets the DIN 51130 R scale by slip angle: R9 6 to 10 degrees, R10 10 to 19, R11 19 to 27, R12 27 to 35, R13 above 35. It warns that R9 and sometimes R10 surfaces will be slippery when wet and that a single class covers a wide CoF range, R10 alone spanning 0.18 to 0.34, so an R number is not a substitute for a PTV. Note that BS 7976-2, the pendulum method, was withdrawn in February 2022, which makes this HSE page the right citation for the thresholds.
Cited in Bathroom Tiles: Types, Cost & Layout, Best Flooring for Kitchens, Bathrooms & Living Rooms, Patio Cost & Materials: Paving, Porcelain & Stone, Resin Floor Cost: 2026 UK Price Guide and 1 more.
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Ministry of Housing, Communities and Local Government
The statutory figures behind a damp diagnosis, and the numbers to quote when a note explains why ground levels or a bridged damp proof course cause rising damp. Paragraph 5.2 requires that in an external wall the damp-proof course should be at least 150mm above the level of the adjoining ground (Diagram 8) unless part of the building protects the wall, and that in an external cavity wall the cavity should be taken down at least 225mm below the level of the lowest damp-proof course, or a damp-proof tray provided (Diagram 9a). For suspended timber ground floors it requires a ventilated air space of at least 75mm from the ground covering to the underside of any wall-plates and at least 150mm to the underside of the suspended timber floor or insulation, with ventilation openings on two opposing external walls of not less than 1,500mm2 per metre run of external wall or 500mm2 per square metre of floor area, whichever is greater; for suspended concrete floors the clear ventilated space is at least 150mm with the same opening sizes. Section 2.39 onwards covers radon, referring to BRE Report BR 211 for protective measures. The 2013 edition was published on 3 September 2013 with changes in effect from 1 October 2013.
Cited in Barge Boards, Fascias & Soffits: Cost & Replacement, Breathable Membranes for Roofs & Walls, Brick Slips & Brick Cladding Systems, Build Basement Cost: 2026 UK Price Guide and 35 more.
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Ministry of Housing, Communities and Local Government
The Approved Document for Part C. It sets out how a suspended timber ground floor must be built and ventilated, including the size of the ventilation openings, the requirement for a free air path between opposing walls, and the clearances beneath the floor.
Cited in Beam & Block vs Concrete Slab Ground Floors, Damp Proof Membranes (DPM) & DPC: Types & Installation, Hardcore, MOT Type 1 & Sub-base Materials Explained, Kingspan & Celotex PIR Boards: Sizes & Cost and 1 more.
- very strong RN-35VE7W cited
Ministry of Housing, Communities and Local Government
Table 0.1a sets separating element performance for dwellings: purpose built walls a minimum 45 dB DnT,w + Ctr, floors and stairs 45 dB airborne and a maximum 62 dB L'nT,w impact; where a dwelling is formed by material change of use the figures relax to 43 dB airborne and 64 dB impact. Table 0.2 sets the laboratory value for new internal walls and floors within a dwelling at a minimum 40 dB Rw. Requirement E2 covers internal walls between a bedroom or a room containing a WC and other rooms, and internal floors, but expressly does not apply to an internal wall containing a door, a wall separating an en suite toilet from its own bedroom, or existing walls and floors in a material change of use. Section 5 gives internal wall types A to D and internal floor types A to C, including timber or metal stud with plasterboard and mineral wool; paragraph 5.14 requires all gaps around internal walls to be filled.
Cited in Acoustic Insulation for Floors & Walls, Acoustic Underlay & Soundproof Flooring, Ceiling Lights: Downlights vs Pendants vs Spots, Concrete Blocks: Aircrete vs Dense vs Hollow and 11 more.
- strong RN-9M7SBG cited
BSI
BS 8203:2017, published 31 March 2017 and current. It gives recommendations for the installation of resilient floor coverings, specifically cork, linoleum, plastic (vinyl) and rubber, on both new and existing structures in conventional flooring applications. It includes design-stage considerations that support proper maintenance and long-term performance but excludes cleaning and maintenance guidance itself, and does not cover access flooring or specialised applications such as static-control flooring. This is the reference standard a note should cite for subfloor condition, acclimatisation and adhesive practice for vinyl and LVT.
Cited in Floor Levelling & Subfloor Prep.
- strong RN-ZPFZGO cited
BSI
BS 8204-1:2003+A1:2009, published 22 December 2003 with Amendment 1 in 2009, committee CB/300, current. Clause 1 gives recommendations for constituent materials, design, work on site, inspection and testing of concrete bases and cementitious levelling screeds that are to receive in situ wearing screeds. It is Part 1 of a series: Part 2 concrete wearing surfaces, Part 3 polymer modified cement, Part 4 terrazzo, Part 5 mastic asphalt, Part 6 synthetic resin, Part 7 pumpable self-smoothing screeds. This is the standard behind screed thickness, mix, curing and soundness-test claims for a sand and cement screed, including its recommendations on inspection and testing.
Cited in Floor Screed Types: Sand-Cement vs Liquid Anhydrite.
- strong RN-ETP4JO cited
BSI
BS 8204-7:2003, published 12 March 2003, committee CB/300, current. Clause 1 gives recommendations for materials, design, work on site, inspection and testing of pumpable self-smoothing screeds, commonly called self-levelling screeds. It notes there are two principal types, one predominantly based on cementitious binders and the other predominantly on calcium sulfate (anhydrite) binders, and it covers both pumpable levelling screeds and pumpable wearing screeds in buildings. As a levelling screed it is intended to receive floor coverings such as textiles, linoleum, PVC, rubber and cork, or rigid floorings. This is the correct citation for a liquid or anhydrite screed note, including the distinction between cementitious and calcium sulfate binders that governs which adhesives and coverings can be used.
Cited in Structural Materials: The Complete Guide.
- strong RN-LLZVVY cited
BSI
BS EN 13813:2002, published 11 November 2002, committee CB/300, under review, identical to EN 13813:2002. It is the product standard for screed material used in floor construction, giving the properties and requirements a screed material must declare, and it is the standard a screed specification designates a product against. BSI publishes no scope preview for this page, so the designation letters and strength classes themselves must be read from the standard or from BS 8204-1 and BS 8204-7, which are the companion codes of practice for laying cementitious and pumpable self-smoothing screeds. Cite this one for the point that screed is a specified product with declared properties rather than a generic site mix.
Cited in Floor Screed Types: Sand-Cement vs Liquid Anhydrite.
- strong RN-3LY0EO cited
BSI
The standard that supplies the imposed floor loading a home gym, a loft store or a mezzanine has to be checked against, and the material densities used to work out the dead load of a new floor build-up. Published 29 July 2002, current and under review, BS EN 1991-1-1 classifies actions, distinguishing self-weight from imposed loads, defines design situations, then gives densities of construction and stored materials, self-weight of construction works and imposed loads for buildings by category of use. A note that says a floor may not take a rack of weights or a large aquarium should point here, together with the UK National Annex, rather than to a rule of thumb.
Cited in Building a Home Gym: Cost & Setup (Garage or Spare Room), Skylights vs Roof Lanterns vs Roof Windows.
- strong RN-G4ZRB1 cited
BSI
BS EN 300:2006, published 31 August 2006, committee B/541, current; it supersedes BS EN 300:1997. Clause 1 states it applies to oriented strand boards, defines the terms, establishes a classification and specifies the requirements, with clause 4 being the classification of boards and clause 5 the general requirements for all OSB types. It states plainly that the values it lists relate to product properties and are not characteristic values to be used in design calculations: test methods for mechanical properties for structural purposes are in EN 789, determination of characteristic values and density for structural purposes in EN 1058, and design characteristic values for OSB in EN 12369-1, with supplementary properties in Annex C. This is the standard that a board marked OSB3 is classified against, so cite it whenever a note specifies OSB for a floor deck.
- strong RN-DNW09X cited
BSI
BS EN 312:2010, published 30 November 2010, committee B/541, under review; it supersedes BS EN 312:2003 and the earlier seven-part series BS EN 312-1 to -7, whose part titles are still visible in the BSI catalogue and name the board categories directly: general purpose boards for use in dry conditions, boards for interior fitments including furniture for use in dry conditions, load-bearing boards for use in dry conditions, load-bearing boards for use in humid conditions, and heavy-duty load-bearing boards for dry and for humid conditions. Clause 1 of the 2010 edition specifies the requirements for flat-pressed or calendar-pressed unfaced particleboards as defined in EN 309, and it is called up in EN 13986 for construction applications where these are referred to as resin-bonded particleboards. It warns the values it lists are product properties and are not characteristic values for design calculations, which come from EN 12369-1 or from testing to EN 789, EN 1058 and ENV 1156. This is the standard behind a chipboard flooring panel grade.
- strong RN-TBEMIM cited
BSI
BS EN 338:2016, published 30 June 2016, committee B/518, ISBN 978 0 580 83526 1, current; it supersedes BS EN 338:2009. Clause 1 establishes the system of strength classes for general use in design codes, giving characteristic strength and stiffness properties and density values for each class, to which EN 14081-1 refers. It applies to all softwood and hardwood timber for structural use within the scope of EN 14081-1. This is the standard that defines C16 and C24, the two softwood classes a merchant sells joists in, along with the C and D class series generally. Clause 5 is the classification of structural timber and clause 6 covers allocation of a population to a strength class by visual grading or machine grading. Cite it whenever a note says a joist is C16 or C24, since the letter and number are a graded characteristic strength, not a species or a quality label.
Cited in Structural Materials: The Complete Guide, Timber Merchants: What They Stock & How to Buy.
- 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-2F1BXP cited
BSI (British Standards Institution)
The current British code of practice for laying a tiled floor, published 31 May 2024. It is the third of what is now a four-part BS 5385 series: Parts 1 and 2 cover internal and external wall tiling, Part 4 covers tiling in special conditions such as wet areas and swimming pools, and Part 3 now covers all rigid flooring. The 2024 revision consolidates and replaces both BS 5385-3:2014 on ceramic and mosaic floor tiling and BS 5385-5:2009 on terrazzo, natural stone and agglomerated stone flooring, so a specification that still cites BS 5385-5 is out of date. Its scope is recommendations for the design, installation and maintenance of floor tiling using ceramic tiles, mosaics, terrazzo tile and slab, natural stone internal and external floorings, and engineered stone for internal flooring. BSI states the revision was driven by ceramic floor tiles becoming thicker and larger, which has made the installation methods for ceramic and stone converge. Covers bedding onto concrete, cement and sand and calcium sulfate screeds, heated screeds, timber and existing hard finishes, plus movement joints and tolerances.
Cited in Floor Levelling & Subfloor Prep.
- strong RN-YM2ENG cited
BSI (British Standards Institution)
STATUS: CURRENT. BS 5756:2007+A2:2017 was published 30 November 2017, the same date as the matching amendment to BS 4978 for softwood, and supersedes BS 5756:2007+A1:2011 and BS 5756:2007. It specifies a method of grading temperate hardwood visually for structural use in the United Kingdom and names four grades in two categories: for large size timber, Heavy Structural Temperate Hardwood THA and THB, and for smaller sections, General Structural Temperate Hardwood TH1 and TH2. This is the standard to cite for a structural oak beam or an oak frame, the hardwood counterpart to BS 4978 for softwood, with the grade to strength class mapping again made through BS EN 1912 and BS EN 338 (green oak commonly reaching D24 or D30). Catalogue page confirms number, title, date, status, scope and the four grade names; the limit tables are paywalled.
- strong RN-BBWVOC cited
BSI (British Standards Institution)
STATUS: CURRENT, and it is the standard that replaced most of the old BS 7533 parts. BS 7533-102:2025 was published 31 March 2025 and gives the code of practice for installing modular paving units of clay, concrete and natural stone, covering bound and unbound surface constructions for paved areas under pedestrian and vehicular loading, all layers from formation upwards (sub base, base, bedding and surface), and recommendations for maintenance and reinstatement. It excludes aircraft pavements, port areas and heavy industrial settings. Its companion BS 7533-101:2021 covers structural design. Because the series was restructured into the 101/102 numbering in 2021 and 2025, a note citing BS 7533-3, -4, -7 or -9 for laying block paving or flags is almost certainly citing a withdrawn part. Catalogue page confirms number, title, date, status and scope.
Cited in How to Lay a Patio.
- strong RN-02VRB9 cited
BSI (British Standards Institution)
STATUS: CURRENT (marked Under Review). BS EN 13670:2009 was published 28 February 2010, is identical to EN 13670:2009 and sits under ICS 91.080.40. It specifies the execution (workmanship) requirements for concrete structures in buildings and other engineering works, covering falsework and formwork, reinforcement and prestressing, concreting, curing, inspection and permitted geometric tolerances, for reinforced, prestressed and precast concrete. It is the site counterpart to design under BS EN 1992-1-1 and to the concrete specification standards BS EN 206 and BS 8500, so a note describing how a slab or foundation should actually be placed and cured should cite BS EN 13670 rather than the design code. It replaced the execution content previously carried in the withdrawn BS 8110. Catalogue page confirms number, title, date, status and scope; the tolerance tables are paywalled.
Cited in Rebar & Steel Mesh: Sizes, Grades & When You Need Them.
- 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-B6U1Z6 cited
BSI (British Standards Institution)
STATUS: CURRENT but time limited. BS EN 1992-1-1:2004+A1:2014 (originally published 23 December 2004) is Eurocode 2, the limit state design code for plain, reinforced and prestressed concrete structures in normal and lightweight aggregate concrete, with specific rules for buildings; it works alongside BS EN 1990 for the basis of design and must be read with the UK National Annex, NA+A2:2014. It superseded ENV 1992-1-1, 1992-1-3, 1992-1-4, 1992-1-5, 1992-1-6 and 1992-3. It does NOT cover plain reinforcement, structural fire design (that is BS EN 1992-1-2), bridges, dams or offshore structures. Important for dating a note: the second generation Eurocode BS EN 1992-1-1:2023 has been published, and BSI will withdraw the UK adoptions of the first generation Eurocodes on 30 March 2028, so any note relying on the 2004+A1:2014 edition has a known expiry date. Catalogue page confirms number, title, date, status, supersessions and scope; the design rules are paywalled.
Cited in Rebar & Steel Mesh: Sizes, Grades & When You Need Them.
- supplier figure RN-MW2IMH cited
Builder Depot
Builder Depot, Engineered Wood Flooring. Held in the cost register as a price source; the passage quoted against it reads: Natural Oak Matt Lacquered T&G 14mm Engineered Wood Flooring GBP 33.54 per M2 Inc VAT ... Natural Oak Matt Lacquered Click 14mm Engineered Wood Flooring GBP 35.94 per M2 Inc VAT ... Chiswick Oak Brushed & UV Oiled 14mm E
Cited in Cork Flooring Installation Cost: 2026 UK Price Guide.
- supplier figure RN-Y521PZ cited
Flooring Superstore
Flooring Superstore, Unfinished Light Oak Herringbone Parquet Solid Wood Flooring. Held in the cost register as a price source; the passage quoted against it reads: £49.99 m2 £39.99 m2 ... 10MM BOARD THICKNESS ... 1 Pack will cover 2.16 m2 ... Add 1 Pack - £86.38
- supplier figure RN-4NWTH6 cited
Selco Builders Warehouse
Selco Builders Warehouse, Quicktherm Underfloor Heating Underlay 10m2. Held in the cost register as a price source; the passage quoted against it reads: Quicktherm Underfloor Heating Underlay 10m2 £32.79 Ex VAT £3.28 per m2 £39.35 Inc VAT
Cited in Cork Flooring Installation Cost: 2026 UK Price Guide.
- very strong RN-IU4DJS
Building Control Northern Ireland
Sets out the legal status of Northern Ireland's Technical Booklets, which differs from how Approved Documents are often described. Under Article 3 of the Building Regulations (NI) Order 1979 the Department of Finance makes the regulations, and it publishes Technical Booklets as guidance in support of them; there is no obligation to follow the methods or standards in the booklets, and any form of construction may be adopted provided the applicant can demonstrate to the district council that the requirements are met. The page also hosts free information sheets on converting an attic, alterations to conservatories, radon in dwellings, exemptions, ventilation, energy conservation, regularisation of unauthorised work, and the BCNI Construction Details updated November 2023.
- very strong RN-2ZSOFV
Department of Finance (Northern Ireland)
Northern Ireland's floor build-up rules, October 2012, guidance to Part C of the Building Regulations (Northern Ireland) 2012. Paragraph 5.4 gives a ground supported floor as: a well compacted hardcore bed not greater than 600 mm deep, because a deeper bed risks excessive settlement and cracking and a suspended slab is then advised, of clean broken brick or similar inert material free of water soluble sulfates (BRE Digest 276); concrete at least 100 mm thick to mix ST2 in BS 8500-1, or ST4 where there is embedded reinforcement; and a DPM above or below the concrete or insulation, continuous with the wall damp proof courses. Where sulfates could contaminate the hardcore the membrane goes at the base of the slab (BRE Special Digest SD 1). Paragraph 5.5 fixes the membrane below the concrete as polyethylene sheet at least 300 micrometres thick, that is 1200 gauge, with sealed joints on a bed that will not damage it; paragraph 5.6 allows the same sheet above the slab without bedding, or three coats of cold applied bitumen solution, protected by a screed or floor finish. A DPM on the warm side of the insulation also acts as a vapour control layer. Radon: no protection below 1 per cent probability, Zone 1 measures (radon membrane) at 1 to 10 per cent, Zone 2 measures (membrane plus subfloor depressurisation such as a sump and stub duct) above 10 per cent.
- very strong RN-4NEHSE
Department of Finance (Northern Ireland)
The impact sound numbers that decide what a flat's floor build-up has to be before any floorcovering is chosen. Table 1a sets the performance standards for separating floors and stairs with a separating function in Northern Ireland: for new dwellings, airborne insulation of at least 45 dB DnT,w + Ctr for both walls and floors, and impact sound of no more than 62 dB L'nT,w for floors and stairs; for dwellings formed by a material change of use, at least 43 dB DnT,w + Ctr and no more than 64 dB L'nT,w. Table 1b sets separate values for rooms for residential purposes. Paragraph 1.11 contains the trap most refurbishments fall into: impact sound insulation tests must be carried out without a soft floor finish such as carpet or foam backed vinyl, so a floor that only passes with the carpet down does not pass. The definitions section defines a floating floor as a floating layer resting on a resilient layer, defines the resilient layer as the thing that isolates the floating layer from the base floor, and defines Delta Lw as the measured improvement in impact sound insulation gained by installing a floor covering or floating floor on a test floor.
- very strong RN-1H8UHK
UK Health Security Agency (UKradon)
Gives a floor-type and concentration decision table for remediation. For a solid floor under 500 Bq per cubic metre the recommended solutions, best first, are a radon sump or positive ventilation; for a solid floor over 500 the answer is a radon sump. For a suspended floor under 500 it is natural under-floor ventilation or positive ventilation; over 500, mechanical under-floor ventilation or natural under-floor ventilation. Warns explicitly that simple actions such as sealing around loft hatches, sealing large openings in floors and extra ventilation do not reduce radon levels on their own, and that completely sealing floors is difficult and can cause rot in wooden floors. Names an active radon sump fitted with a fan as the most effective method, working best under solid floors and under suspended floors where the ground is covered with concrete or a membrane. Advises contacting UKHSA for levels above 1000 Bq per cubic metre, and the local council Environmental Health Department for advice.
- very strong RN-6PQK9U
UK Health Security Agency (UKradon)
UKHSA recommends that radon levels be reduced in homes where the average exceeds 200 becquerels per cubic metre, the Action Level, and states that this recommendation is endorsed by Government. The Action Level refers to the annual average concentration, so a valid measurement uses two detectors, one in a bedroom and one in a living room, left in place for three months to average out short-term fluctuations. Separately defines a Target Level of 100 Bq per cubic metre as the ideal outcome of remediation in existing buildings and of protective measures in new buildings, and advises that where a result falls between the Target and Action Levels action to reduce the level should still be considered, especially where a smoker or ex-smoker lives in the home. Radon is described as a colourless, odourless radioactive gas formed by decay of naturally occurring uranium in rocks and soils.
- very strong RN-B3IMK7
UK Health Security Agency (UKradon)
UKHSA's routing page into radon guidance written for the four audiences a renovation note serves, and the place to send a builder who needs the building regulations position on radon protective measures in a new floor. It separates guidance for householders, covering radon and house sales, health risks and how to measure; for employers, covering the health and safety duty to test a workplace; for professionals, explicitly including builders who need building regulations guidance and solicitors handling property transactions; and for local authorities and housing associations, including how to check whether housing stock sits in a radon Affected Area. It also carries the address search and the domestic and workplace measurement packs.
- very strong RN-FXA893
Department for Communities and Local Government
The official answers to the questions Part E raises on a flat conversion or a floor upgrade, March 2016, ISBN 978-1-4098-4806-6. It confirms that pre-completion sound testing is required except where robust details have been used, and that organisations carrying out the testing should preferably hold UKAS accreditation or a European equivalent, or be members of the Association of Noise Consultants registration scheme; when testing was introduced in 2003 there were too few such bodies, but there are now over 50 UKAS/ANC test organisations, and clients should be told early that they must employ one. It draws attention to paragraph 1.8 of Approved Document E, which advises that sound insulation testing should not be carried out between certain spaces because results may be unreliable, and notes reduced accuracy when measurements are made in small rooms, while confirming that separating walls and floors subject to requirement E1 must always meet the standard whether or not they will be tested. It also covers noise from neighbours, care homes, houses in multiple occupation and reverberation in common internal parts.
- very strong RN-78SSH6
Department of Finance (Northern Ireland)
NORTHERN IRELAND, giving a fourth set of U-values distinct from England, Wales and Scotland. Table 2.2 sets limiting area-weighted average U-values in W/m2.K with a maximum permitted at any point in brackets: wall 0.18 (0.60), floor 0.18 (0.60), roof 0.16 (0.30), party wall 0.00 (0.60), and windows, roof windows, glazed rooflights, curtain walling and pedestrian doors 1.40 (3.00). Where the space heating source is underfloor heating the maximum floor U-value tightens to 0.15. Compare Wales at 0.13 for roofs and Scotland at 0.12, against NI's 0.16. Paragraph 2.43 limits the extent of external doors and glazed openings in a dwelling to no more than 25 per cent of the dwelling's floor area, and the limiting air permeability is 10 m3 per hour per square metre at 50 Pa, looser than the Welsh 8.0. U-values are calculated to BRE Report BR 443. A swimming pool basin must achieve not more than 0.25.
- very strong RN-Z55Y2I
Historic Environment Scotland
Free HES guidance on how a traditional house was designed to breathe, useful whenever a note explains why blocking air bricks or sealing a chimney causes damp. Published 1 October 2008 by Historic Scotland (now HES), INFORM Guide, 653 KB PDF, audiences Planners and Owners and Conservation and Heritage enthusiasts. Scope stated on the page: the importance of ventilation in a traditionally built structure, then the various ways ventilation is provided, specifically SUB-FLOOR VENTILATION and CHIMNEYS, and issues surrounding masonry walls and plastered surfaces. Cite it alongside Approved Document F when a note covers suspended timber floors, chimney capping or draught-proofing an older house.
- 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-QAE4YS
Ministry of Housing, Communities and Local Government
The canonical landing page for Part E of the Building Regulations in England, hosting the 2015 edition published 4 March 2015, 3.74 MB, ISBN 978 1 85946 616 2, and the citation to use when the question is which edition of Part E governed a conversion. Its stated scope is sound insulation requirements in dwelling-houses, flats, rooms for residential purposes and schools, which are requirements E1 separating walls and floors between dwellings, E2 internal walls and floors within a dwelling, E3 reverberation in common internal parts, and E4 acoustic conditions in schools. Earlier editions are held at the National Archives rather than on this page, which matters when checking what applied to a flat conversion carried out before 2015. The page also records that since April 2023 the Building Safety Regulator reviews building standards for all buildings in England. The dB performance values themselves, the floor treatments FFT1 and FFT2 for a material change of use, and the pre-completion testing regime sit in the linked PDF and in the separate Part E FAQ.
- very strong RN-TCQ74D
Scottish Government
The Scottish trigger for building a radon barrier into a ground floor, which is the point at which a floor build-up stops being a free choice. Standard 3.2 sets the action level at 200 becquerels per cubic metre, the level above which UKHSA (formerly Public Health England) recommends radon in homes be reduced. Protective measures are required where a dwelling sits in a designated radon probability area, defined as ground where 1 per cent or more of existing dwellings exceed 200 Bq per cubic metre, or in ground where radon is known to exist. The measures themselves are not restated in the handbook: it directs the designer to BRE publication BR 211 Radon: guidance on protective measures for new buildings, with BRE Good Building Guides GG 73 and GG 74 for extensions and dwellings, and to the Indicative Atlas of Radon in Scotland for the mapping. UKradon.org is cited for postcode-level checking. Note the level is an action level, not a limit, and it applies to the annual average rather than a spot reading.
- very strong RN-P8YSU2
Scottish Government
The Scottish build-up rules for a ground floor before any floorcovering goes down. Standard 3.4 requires that moisture penetration from the ground threatens neither the building nor the health of occupants. For a ground-supported concrete floor the guidance gives a hardcore bed at least 100 mm thick of clean broken brick or other inert material free from fine material and water-soluble sulphates, a concrete slab at least 100 mm thick, and a damp proof membrane placed above the slab, below it, or sandwiched, jointed and sealed to the damp proof course following CP 102:1973 Section 3. For a suspended timber floor the site covering is either a DPM to CP 102, or 50 mm of concrete on 0.25 mm polyethylene sheet, or 100 mm of concrete, with a dpc under the wall plates and a ventilated void of at least 75 mm from the site covering to the wall plates and 150 mm to the joists. Suspended concrete floors need a 150 mm ventilated void to the underside of the slab or beams with ventilators in opposite external walls. BS 8102:1990 is cited for below-ground walls and basements.
- very strong RN-UHBO2G
Welsh Government
The Welsh energy efficiency guidance, first published 14 June 2016 and last updated 7 April 2026. It carries volume 1 for dwellings and volume 2 for other buildings as current PDFs, and a new Approved Document L volume 1 for dwellings that takes effect on 4 March 2027. Any note quoting fabric U-value targets for a floor, wall, roof or a conservatory's thermal separation should state which nation the figure belongs to, since Wales publishes its own Part L with its own commencement dates rather than adopting the English edition.
- strong RN-QITUKE
British Board of Agrément
The body behind the BBA Agrement certificate that manufacturers of insulation, membranes, adhesives and flooring systems quote, with a searchable MyBBA certificate database covering products, people certification and product testing. Carries an important current caveat a note should not miss: on 26 February 2026 the BBA was notified that UKAS had instigated a temporary suspension of its accreditation status following a change in corporate structure in 2025, meaning it is at present unable to deliver accredited testing, inspection and certification activities, with UKAS confirming the suspension covers all activity to BS EN ISO/IEC 17020, 17021, 17025 and 17065. Advice to look for a BBA certificate should be checked against that status.
- strong RN-PMJ7YM
BSI
The workmanship half of the screed rules, the companion to the design recommendations in BS 8204. Published 7 November 2003 and still current. It gives recommendations on laying cementitious levelling screeds and wearing screeds, and guidance on basic workmanship for conventional building work. The current edition fixed the naming that still confuses specifications: a screed is a levelling screed where it will receive a final flooring and a wearing screed where it forms the finished surface. Other changes it records: bases carrying rigid insulation boards under a floating screed must be levelled by filling depressions so the boards cannot rock on high spots; material specifications were updated to the European cement types and standard strength classes; cements with slag content above 35 per cent and equivalent combinations are excluded from levelling screeds for lack of experience; cement bags were halved to 25 kg so mix calculations were restated; slurry bonding of the edges of day work joints is recommended before laying fresh screed to reduce curling at butt joints; and the items to be checked during progress and on the finished screed are listed. Curing where cement is below strength class 42.5 N follows BS 8204-1 and BS 8204-2.
- strong RN-OQLJWC
BSI
BS 8201:2011, published 31 October 2011, committee B/543, current; it supersedes BS 8201:1987. Clause 1 gives recommendations for laying board, pre-assembled board, strip, mosaic, overlay, parquet, block, end grain, multi-layer and wood-based panel flooring. It expressly does not cover the protection given to a floor by floor coverings or surface finishes, nor floors for temporary structures or floors intended for limited use. This is the standard to cite for acclimatisation, subfloor moisture, expansion gaps and fixing method when comparing solid to engineered wood, and for laying chipboard, OSB and plywood floor decks.
- strong RN-OUKOVE
BSI
The code for a polished or power-floated concrete floor left as the finish rather than covered, published 22 December 2003 with amendment A2 in 2011 and current. BS 8204-2 gives recommendations for constituent materials, design, work on site, inspection and testing of in situ concrete direct finished base slabs, and covers concrete used as the wearing surface plus wearing screeds, formerly called high strength concrete toppings and granolithic toppings. It applies to both ground-supported and suspended floors and expressly leaves structural design to BS 8110-1, so it is the surface quality reference, not the structural one.