May 2019

More documents

Recommendations

Info

An Inspector Calls DON’T BE THE FALL GUY WHEN IT COMES TO FLAT ROOFING In our regular monthly column – ‘An Inspector Calls’ – Total Contractor has teamed up with the experts at BMI UK & Ireland to help you avoid the common pitfalls that can often cost you both time and money, and ultimately help you achieve roofing success. This month, the Inspector looks at how updates in BS 6229:2018 can stop you being the fall guy when it comes to flat roofing. One of the most eye-catching amendments in the revision of BS 6229:2018 was the reference to falls. This is now much clearer, stating that “all flat roof surfaces (including gutter beds) should be designed with a fall of 1:40 to ensure finished drainage falls of 1:80 are achieved. This should take account of construction tolerances, permitted deviations and deflection under load, and account for deflections/settlement.” In other words, any design should allow for all factors that could reduce or hinder the drainage, eliminating the risk of ponding on roofs. Without these considerations, it is highly likely standing water will occur. Although improvements in membrane technology and performance have increased significantly, standing water may still result in additional and unnecessary stresses in the membrane, particularly in the winter when that standing water freezes. Furthermore, in the event of a defect being present in the area of the ponding, greater water ingress will occur when compared to a well-drained roof. Accelerate the ageing process Standing water is typically defined as water that remains on the roof for longer than 48 hours, and whilst this is not an immediate threat, it can accelerate the natural ageing process and have a detrimental effect on the membrane’s lifespan. It’s possible that standing water can still occur even when the structural deck has a fall within it, as compressed insulation, blocked or faulty drainage and damaged membranes can all contribute towards this issue too. Regular maintenance can therefore reduce this risk, alongside reducing the number and weight of items permanently stored on the roof. Another contributing factor could be the sequencing of membrane laps and edge details sitting proud of the finished floor level, consequently reducing the water’s ability to navigate past the resulting water-check. The reference to falls is all the more pertinent given that, these days, there are certain thirdparty certified waterproofing and insulating Above: Ponding can shorten the life of a roof. Below: Standing water due to lack of fall. systems that have gained approval for use with zero falls. Hot melt systems in particular are popular for this area of work. For these systems, zero falls are acceptable, but negative falls are not, so should be corrected. It is not really acceptable in this day and age for any contractor to install roof decks with large depressions, back falls and non-draining areas. To ensure a zero fall finished surface i.e. one that is totally flat, a design fall of 1:80 should be used, along with a detailed structural analysis to account for construction tolerances, settlement and deflection under load. Remedial action If sites have negative falls, thereby increasing the likelihood of ponding, then remedial action has to be taken before the roof system is applied. This could be by laying a localized screed to falls and firings, fitting tapered insulation or fitting additional rainwater outlets at the lowest points. As a result, the roofing contractor should expect a flat, properly drained surface on which to lay the specified system and the finished roof should not suffer from ponding or inadequate drainage. Contact BMI National Training Centre 01285 863545 www.redland.co.uk/training @_Redland / @Icopal_UK 16 TC MAY <strong>2019</strong>
Insulated Panel Systems UK & Republic of Ireland The QuadCore Envelope Your high performance insulated building envelope by design. #MoreWithQuadCore QuadCore Topdek Flat Roof panel with U-values as low as 0.14 W/m²K QuadCore Architectural Wall Panel Systems with 4 hours Fire Integrity to BS476: Part 22 QuadCore RW Trapezoidal Pitched Roof panel with U-values as low as 0.12 W/m²K Manufactured with an HCFC, CFC and HFC free, fibre-free QuadCore insulation core Protected for up to 40 years with a QuadCore Envelope System Warranty All QuadCore Envelope Panels tested to FM 4882 Manufactured at our UK facilities that are certified ‘Very Good’ under BES 6001: Responsible Sourcing of Construction Products Single-Source System Manufacturer: Structural Steel, Daylighting, Fabrications, Safety Systems and Rooftop Energy Systems all available from Kingspan QuadCore Architectural Wall Panel and RW Trapezoidal Wall Panel with U-values as low as 0.12 W/m²K quadcore.kingspan.co.uk Kingspan Limited Greenfield Business Park No.2, Holywell, Flintshire CH8 7GJ Tel: +44 (0) 1352 716100 www.kingspanpanels.co.uk
Page 1 and 2: MAY 2019 FEATURES • DON’T BE TH
Page 3 and 4: I V Editor’s Comment MATT DOWNS E
Page 5 and 6: REGULARS 18 NFRC TECHNICAL TALK In
Page 7 and 8: SUM OF THEIR PARTS Bespoke solution
Page 9 and 10: THE AWARD WINNING ALUMINIUM LANTERN
Page 11 and 12: Handrails:- EasyGuard free-standing
Page 13 and 14: The choice for your polycarbonate p
Page 18 and 19: NFRC Technical Talk SUMMARY OF CHAN
Page 20 and 21: Material Talk AT ONE WITH YOUR PROJ
Page 22 and 23: Business Talk PROS & CONS OF RECRUI
Page 24: Pitched Roofing PREVENTING GABLE EN
Page 27 and 28: oofing courses to help grow the bus
Page 30 and 31: Have you heard? Not only is the ult
Page 32 and 33: Perfectly Pitched KNOW WHICH WAY TH
Page 34 and 35: Perfectly Pitched Zonal Limitations
Page 36 and 37: Fall Protection MAINTAINING/SERVICI
Page 38 and 39: Trussed Rafters WHAT YOU NEED TO CH
Page 40 and 41: Liquid Roofing & Waterproofing THE
Page 42 and 43: Liquid Projects DON’T BE BUSY EAR
Page 44 and 45: Liquid Projects Works could range f
Page 46 and 47: Efficient Drainage FLAT ROOF DRAINA
Page 48 and 49: Efficient Drainage period. It is us
Page 50 and 51: EPDM Roofing SPEEDING THINGS UP: RO
Page 52 and 53: EPDM Roofing by long-term watertigh
Page 54 and 55: Safety at Height MAXIMISING THE BEN
Page 56 and 57: Roofing Updates For further info on
Page 58 and 59: Roofing Updates For further info on
Page 60: Off-site Construction “THERE ARE
Page 63 and 64: A NEW COMPOSITE CLADDING SYSTEM THA
Page 65 and 66:
HIGH PERFORMANCE LIQUID WATERPROOFI
Page 67 and 68:
No more space to insulate Ultra-hig
Page 69 and 70:
Complex Worksites. Simplified Safet
Page 71 and 72:
“These digital platforms ensure a
Page 74 and 75:
The Apex WILL T LEVELS ATTRACT TALE
Page 76:
METAL RAINWATER & ROOFLINE PRODUCTS
show all

May 2019

Create successful ePaper yourself

Delete template?

Save as template?