Plenum Testing for
Air Tightness Compliance

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Stroma Built Environment is a market-leading provider or Air Tightness and Plenum Testing. We’re working on projects from early design stages to ensure plenums are correctly sealed for air tightness testing.

Nationwide Service

One of the largest teams of ATTMA Air Tightness Engineers and Consultants in the UK, ensuring a quick response for testing.

Design Stage Reviews

Desktop and on-site design reviews to assess your design before plenum testing, ensuring you pass first time.

Compliance Experts

Technical expertise throughout the construction process, including support with interpreting Building Regulations.

Pass Your Plenum Test First Time

A plenum is a space within a building that facilitates air circulation for heating or air conditioning systems; usually under a raised floor or between ceiling structures. Plenums are important as they provide pathways for heated/conditioned air or return airflows, which are normally greater than atmospheric levels.

Stroma Built Environment provides desktop and on-site design reviews to assess your design and offer advice to ensure plenums are adequately sealed and passes air tightness testing first time. Our plenum advice includes:

Air tightness requirements of your plenums for compliance

On-site testing of plenums, compared to laboratory testing

Effects of contractor work on the air tightness of a plenum

How pipes and cabling affect the air tightness of a plenum

Plenum remedial works



An estimated 70% of plenums fail the first air test in any building. Our Air Tightness Consultants can advise on your design and recommend remedial works to ensure your plenums are correctly sealed.

Sarah Rogers, Air Test Technician

The Air Testing Plenum Process

An Air Tightness Consultant will visit your site to carry out a Plenum Test. The Plenum Testing process includes:
• Removing a floor tile from the plenum and connecting a tunnel to a fan, once all air handling ducts serving the test zone are turned off, isolated, and temporarily sealed.
• Once the area has been prepared and correctly sealed, the air tightness test takes place, including taking several pressure readings.
• The specification for the plenum is usually determined by the project’s Mechanical Engineer. We’ll need to understand the specified pressure (e.g. 0.5l/s/m2 @ 50 Pascals).

We recommend an on-site visit as soon as the floor is in place to ensure Plenums are correctly sealed for testing. If you’ve already failed a plenum test, we can provide remedial advice post design, ensuring you pass your next plenum test.

Compliance Pack Bundle

Stroma Built Environment offers complementary services for Plenum Testing for
Air Tightness Compliance to reduce procurement costs, gain project efficiencies and achieve full compliance and sustainability targets for your project.

Recommended services
Air Testing
Air Tightness Consultancy
Remedial Air Sealing
Room Integrity Testing
Temporary Air Sealing

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