Navigating product performance for balconies and roof terraces poses a unique set of challenges for designers and architects, especially in high rise building projects. While certain aspects such as fire ratings must adhere to strict regulations, other factors can be more complex. One such element is wind uplift where the lack of standards makes it difficult to assess if an external flooring product will perform as required.
calculating wind uplift
Wind uplift is the force generated by wind pressure on a building’s roof or flat surfaces, such as balconies and terraces. When wind flows over the structure, it creates pockets of air pressure which can lift unsecured elements such as loose-laid paving tiles. This can constitute a significant risk, with the potential to cause serious damage to both property and people.
Wind uplift calculations are specific to each building, taking into account factors such as building height and locations on the building, along with proximity to neighbouring structures and predicted wind speeds. With this data, architects and specifiers are better equipped to engage with manufacturers on wind uplift solutions that meet their requirements.
While this would appear straightforward, the inconsistency of testing standards for paving systems makes it challenging when comparing different solutions.
TESTING OVERVIEW
Buzon’s latest wind uplift solution, A-FIX-WIND-SAFE has undergone rigorous testing by Lucideon whose testing process involves simulating real-world conditions to evaluate performance under various wind scenarios. In Buzon’s case, this involved subjecting a test rig to a variety of forces to determine whether secured pavers would come free from the rig.
As part of the testing process, deflection or movement of the system is measured during and after testing, as well as noting damage or breakage of any system component as a result.
WHY DEFLECTION MATTERS
Whilst a wind uplift solution is designed to specifically resist the effects of severe weather, it is equally important that external flooring remains robust, usable and safe once the weather event has passed. If high levels of deflection are observed, it indicates that the system components have probably endured significant stress, with the potential for the system to be no longer level or safe to walk on, especially if components such as pedestals have broken during the process.
Choosing the right solution will not only secure pavers, but prevent costly remedial work which would be required to make external areas safe and usable again.
RIGOROUSLY TESTING THE SOLUTION
Buzon’s test rig was designed to test four systems when used in conjunction with A-FIX-WIND-SAFE: the Class A fire-rated A-PED used with and without A-PED joist, and the DPH polypropylene pedestal with and without ALUrail joist, tested with two sizes of 20mm porcelain tiles. This effectively tested both non-combustible and BROOF(t4)-type solutions built in equal proportion, with a consistent testing approach.
The rig was subjected to four individual tests:
Progressive Load Test – Each system is subjected to a continuous wind uplift pressure which is stepped up in 500 pascal increments every 20 seconds. Buzon samples were subjected to the maximum load of 6000 pascals without any detrimental effects of the system.
Cyclic Wind Loading (blanked off) – A phased load test which increases over time. The rig has blanked off areas which blocks free air movement below the tiles. Buzon samples were subjected to a maximum of 6000 pascals in pulsed cycles with no detrimental effects to any of the systems and no failures were observed.
Cyclic Wind Loading (open-ended) – As the above but with open section allowing free movement of air. Buzon samples were subjected to a maximum of 6000 pascals in pulsed cycles with no detrimental effects to any of the systems and no failures were observed.
Static Load Test – An airbag is used to measure how well the pedestal system can resist upward force by filling it slowly until the sample fails. Buzon samples were solid when subjected to a force between 1 and 9 ton per square metre depending on product configuration.
HOW DOES BUZON MEASURE UP?
Buzon’s systems demonstrated robust resistance to wind uplift, indicating a high level of safety when used with A-FIX-WIND-SAFE system. with all four tests concluding that it would take an extreme force to push each system to the point where a tile would be free and pose a safety risk. No broken components and crucially, no lift on the pavers were recorded.
Deflection rates across the test scenarios were minimal, (see table below) showing that the Buzon system is extremely robust and stable, both during and after exposure to extreme forces.
Cyclic Wind Load Testing with Blanked off end |
Deflection (mm) @ Load (Pa) |
|||||
System / Load |
2400 pascals |
3600 pascals |
4800 pascals |
5400 pascals |
6000 pascals |
Post-test / Residual |
A-PED |
0.66mm |
1.17mm |
1.22mm |
1.22mm |
1.24mm |
0.08mm |
DPH |
0.16mm |
0.22mm |
0.25mm |
0.41mm |
1.01mm |
0.03mm |
A-PED with A-PED-JOIST |
0.23mm |
0.4mm |
0.45mm |
0.53mm |
0.57mm |
0.38mm |
DPH with ALUrail |
0.00mm |
0.01mm |
0.01mm |
0.01mm |
0.02mm |
0.01mm |
NOT ALL TESTING IS CREATED EQUAL
Ultimately, not all manufacturers test as extensively as Buzon - if at all. Some only perform single tests on their products, thereby limiting the reliability of their results. Those systems may be deemed safe but are demonstrably more vulnerable to external pressures resulting in unstable or even unusable terraces.
With enhanced testing and insignificant rates of deflection, Buzon UK systems demonstrate a robust resistance to wind uplift. This provides added assurance for architects and specifiers, highlighting the importance of using a supplier who tests for these extra elements.
You can read the full test report here.
get supported by buzon
Don’t let wind uplift get the better of your project. Talk to an expert about how you can ensure stability and security on your paving project.
Simply call +44 020 8614 0874 or email info@buzonuk.com for more information.