Constructing Floor Plenums to Pass Air Tightness Testing

There are many considerations when designing and constructing floor plenums to pass the air tightness testing. 
In offices, carpet tiles are usually laid over the raised access floor, if joints between carpet tiles are not lined up with the joints between the raised access panel’s floor tiles or panels, the air leakage will be reduced, particularly if the carpet tiles are glued in place. That said, the laying of carpet tiles should not be relied on to achieve the target for the raised access floor itself as these can debond over time resulting in multiple air leakage paths throughout the raised access floor.

Many raised access floors include electrical and date boxes. The air leakage of these boxes should be ascertained, to ensure that they will not significantly contribute to the raised access floor leakage, and reduce the air flow to the grills or diffusers. Where there are decorative or functional connections through the raised access floor, for example cabling to display boards, suitable method of air sealing these penetrations should be designed.
The perimeter of the floor plenum where the access floor meets the wall is often an area of increased air leakage. To minimise this leakage it may be beneficial to fix a length of metal angle along the perimeter of the floor. Lengths of closed cell board or neoprene strips will increase the quality of the seal between the raised floors and the wall and should prevent excess air leakage.
The walls of floor plenums are most the most vulnerable to air leakage as they are dependent on the type and quality of construction. Plasterboard can be used as the air tightness barrier; however, care should be taken to ensure all joints should be sealed where boards abut other boards, walls, floors and the underside of the raised access floor. This is the same for coated mineral fire boards used in conjunction with fire mastic, the boards should be specified with an air leakage rate of 0.15 l/(s.m2)@50Pa with a life expectancy of at least 25 years.
While poured in-situ concrete floors don’t have any significant air leakage, hollow-core and solid composite precast planks need to be sealed along the plank joints and carefully sealed around service penetrations. Beam and block floors need to be covered by a screed to prevent excess air leakage.
Testing procedure BG65 / 2016 contains lots of useful information on how to prepare your floor plenum to pass the air tightness test. 

APT Sound Testing undertakes all types of Floor Plenum Testing to BG65 / 2016. Using the latest equipment we can test the largest floor plenums over 1000m2.  

If you would like more information on our floor plenum testing please contact us at: info@aptsoundtesting.co.uk or visit our Floor Plenum Testing page on our website. Alternatively you can call us on: 01525 303905 or check out our other services at: www.aptsoundtesting.co.uk 


Location: London, UK

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