August 2018

More documents

Recommendations

Info

Perfectly Pitched should follow the underlay manufacturer’s installation guidance to ensure harmful condensation does not occur in the roof space. New definitions for ceiling types In this latest amendment to BS 5534, the previous term ‘well-sealed ceiling’ has been replaced with new definitions of a ‘continuous ceiling’ and a ‘discontinuous ceiling’. This enables each to be defined in a clearer, more technical manner as the type of ceiling has implications for the control of condensation in the loft space as well as the wind uplift resistance of unsupported underlays. A continuous ceiling; i.e one that has an air permeability of 30mm² per square metre or less, will require less or even no roof space ventilation, depending upon the roof construction and product types. Also, an underlay with an uplift resistance of 1600 N/m² or more can be used in conjunction with a continuous ceiling within all geographical zones within the UK (provided other criteria are met). By contrast, a discontinuous ceiling – i.e one that has an air permeability of more than 30mm² per square metre – will require more ventilation in the loft space and the underlay must have a wind uplift resistance of not less than 1900 N/m² to be used within all UK geographical zones (again, subject to other criteria being met). New wind loading ‘shielding factor’ for air permeable underlays It has long been understood that a proportion of the wind loading on roof tiles is actually borne by the substrate – i.e the underlay or sarking – this is known as the shielding factor. However, recent research has shown that air permeable underlays, by their very nature of allowing air to pass through them, share less of the wind load under certain conditions, meaning that a higher proportion of the wind load is then borne by the roof tiles. More research is required to better understand the exact consequences of this, but in the meantime, a new ‘Shielding Factor’ value has been included in this latest edition of BS 5534 to allow for the lesser load being taken by air permeable underlays. In practice, this means that the tile manufacturer must take this into account when calculating roof tile fixing specifications. So since July, you’ll now see a new question about the underlay type on tile manufacturers’ fixing request forms. All Imerys tiles, fittings and accessories fully comply with the requirements of BS 5534 and BS 8612. Also, all fixing specifications carried out by Imerys from July 1st take into account air permeable underlays where applicable. Contact Imerys Roof Tiles www.imerys-roof-tiles.com @imerys @johnmercer3 Below: An image of an Imerys Beauvoise roof. 34 TC AUGUST <strong>2018</strong>
NOW WITH A NEW SITE WITH TRAINING FACILITIES IN HUDDERSFIELD SEE US AT Give us a call about quality flat roofing solutions • SYSTEM WARRANTIES AND ACCREDITATIONS • TECHNICAL SERVICE AND SUPPORT www.flex-r.co.uk Enquiries: 01494 448792 • TRAINED SPECIALIST REGISTERED INSTALLERS Industry leading, fleeceback singleply High performance, liquid waterproofing Sandswood House, Hillbottom Road, Sands Industrial Estate, High Wycombe, Buckinghamshire, HP12 4HJ
Page 1 and 2: AUGUST 2018 Flat roof details Asbes
Page 3 and 4: Editor’s Comment MATT DOWNS EDITO
Page 5 and 6: REGULARS 16 CONTRACT TALK Stuart Ba
Page 7 and 8: DON’T MISS OUT - 85% SOLD, SECURE
Page 9 and 10: ALL ALUMINIUM LANTERN ROOF FITTED I
Page 11 and 12: SEE US AT Handrails:- EasyGuard fre
Page 13 and 14: SEE US AT WE ARE PIONEERS OVER 40 Y
Page 15 and 16: MANUFACTURERS OF SPECIALIST TEST EQ
Page 17 and 18: Note : Plywood Stoped Short To Ensu
Page 19 and 20: For fu rther inf ormation or a hire
Page 21 and 22: SEE US AT You don’t need tools to
Page 23 and 24: QUICK, COST EFFECTIVE ROOF REPORTS
Page 26: Contractor’s Q’s “ONE VERY IM
Page 29 and 30: Complete Building Envelope Solution
Page 31 and 32: THE NORTH STARS! Kieran Forster is
Page 33: precision, quality & value one name
Page 37 and 38: PLANUM CLAY ROOF TILES MADE FOR EXC
Page 39 and 40: The 12 people on our course came fr
Page 41 and 42: SFS fixings shape our landscape Ext
Page 43 and 44: SEE US AT LINCOLN CLAY PANTILE. TRA
Page 45 and 46: Marley Eternit’s advice: • Use
Page 47 and 48: SEE US AT PROTAN BLUEPROOF - A ROOF
Page 49 and 50: SEE US AT
Page 51 and 52: passionate about slate one name SEE
Page 53 and 54: Go Further with SupaLite SupaLite d
Page 55 and 56: LIQUID WATERPROOFING BITUMINOUS WAT
Page 57 and 58: Easy-Trim are proud to announce tha
Page 59 and 60: LIFT THE LID ON SMOKE & HEAT Formin
Page 61 and 62: Innovative upgrade & refurbishment
Page 65 and 66: ROYAL SEAL OF APPROVAL The first ex
Page 69 and 70: ideal for use on conservatory conve
Page 71 and 72: SEE US AT Polyroof, in conjunction
Page 73 and 74: Article heading Total Recruitment S
Page 75 and 76: Sponsored by DRY ROOFING PRODUCTS W

August 2018

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?