Duct Sealing Solutions with Filoform
Published 20 May 2025
How Do I Select a Duct Sealing Solution?
At Thorne & Derrick, we pride ourselves on working with industry leaders to deliver innovative, reliable, and compliant solutions to our customers. In this edition of Ask the Experts, Ian Joynson, Technical Specialist at Filoform, talks all things duct sealing — from common challenges in the field to the importance of long-term protection.
Filoform’s Ian Joynson shares expert guidance on what to consider when selecting the right duct sealing solution:
“Selection should start by understanding the specific application and what the seal needs to achieve. Consider:
➖ Are there cables present, and how many?
➖ Is water ingress an issue? If so, how much?
➖ Is fire protection required?
➖ Does the duct enter a building?
➖ Are gases or chemicals a concern?
The right solution should be chosen during the design phase, where sealing requirements can be aligned with the overall project scope.
Most specifications will demand resistance to water, gas, and sometimes fire or chemicals. Expected seal life is also critical — and any reputable manufacturer should be able to validate this.
Avoid over-engineering the seal design. Ultimately, a duct sealing solution that meets the specific needs of the application is the right solution.”
Thorne & Derrick is trusted distributor of Filoform duct sealing systems, supplying reliable and high-performance solutions to contractors, engineers, and project teams across the UK and internationally. Whether you’re sealing cable ducts in substations, renewable energy sites, or industrial facilities, we provide expert support and fast delivery to help you get the job done right.
Duct sealing and sealing products manufactured by Filoform, including the Filoseal range, are installed to provide gas tight and watertight sealing for cable duct entries – protecting underground cables and substation ducting infrastructure against flood and migration of flammable and toxic gas hazards. Fire resistant version also available – suitable for sealing LV-HV power, telecoms and fibre optic cables.
Filoform manufacture and supply quality products and solutions to connect, seal and protect low, medium and high voltage underground cable networks.
Thorne & Derrick provide competitive prices and fast delivery from stock for the complete range of Filoform duct seals and cable joints.
View the complete range of Filoform products.
FiloSeal+HD Duct Sealing System
