Filoform MD5 Duct Sealing System Vs DIY Expanding Foam

Published 02 Jan 2024

Expanding Foam vs Duct Sealing System | Filoform

DIY Expanding Foam vs MD5 Duct Sealing System | Filoform

Filoform MD5 Sealing System

vs DIY Expanding Foam

Most UK utilities have banned the use of expanding foam as a measure to effectively seal cable ducts against water ingress, gas migration or fire spread. Failure to correctly and safely seal cable ducts can inflict catastrophic damage to LV MV HV Electrical Distribution Networks, Substations and Power Supply.

Thorne & Derrick International are the UK distributors for Filoform, a leading manufacturer of cable joints, duct seals and special resins for installation in the utilities, telecom, traffic, rail, fibre optic, street lighting and construction industries.

Polyurethane foam (PU) has witnessed a increase in popularity as a construction material due to its versatility. PU can be applied to walls, roofs, ceilings, floors providing insulation and structural support. Technological advancements have overcome engineering challenges, allowing for low-density foam products that are easy to install on-site.

Duct Seals – Sealing Cable Ducts

uSING Filoform MD5 Duct Sealing VS DIY expanding foAM

Whilst expanding foam serves well for sealing small gaps, filling voids, cracks and insulating it falls short beyond these applications. Often comprised of subpar polyurethane, many expanding foams lack the necessary properties for effective sealing or adhesion.

The use of expanding foam in construction and maintenance projects across various industries have grown over time; however it faces major problems when applied wrong, or designed into a project where the foam specifications doesn’t match the requirements of the projects.

Comparing MD5 Duct Sealing Resin to Generic expanding foam

Assessing the particular duct seal scenario and determining the project’s goals are important when selecting an efficient seal. Taking into account elements such as :

Cable Presence
Water blocking specifications
Fire Stop standards
Building entrance points
Gas and chemical problems

During the design phase choosing a sealing system that fits the needs of the entire project should be made easier by taking the circumstances into consideration.

Sealing Ducts require precision, a professional would strongly advise against using DIY expanding foam for this purpose due to potential complications. For guidance in your inquiries please contact us today!

Properties	Generic expanding foam – DIY stores	MD5 Duct Sealing Resin – Two Components
Cell Structure	Large, Weak, soft foam – 70% closed	100% closed, small, strong, durable
Expansion Rate	35 x can volume – Very quick & controlled	8 x volume – Slow & easy to control
Temperature Resistance	+194°F / +90°F	+248°F / +120°F
Compressive Strength	3 Newton / cm² / 0.67 pounds of force	60 Newtons / 14 pounds of force
Resistance to Hydrocarbons	No	Yes
Water Resistant	Yes – temporarily	Yes permanently – upto 1.5 bar / psi

MD5 Sealing System vs DIY Expanding Foam | FILOFORM

hOW TO SELECT A DUCT SEAL SOLUTION

It is important to evaluate specific duct sealing situation and identify the objectives of the seal. For example:

Is there cables in the duct and how many?
Does water need to be blocked? How much water?
Is a firestop needed?
Does the conduit enter the building?
Are gases or chemicals a concern?

This process should take place during the design phase aligning the seal requirements with the overall product specifications. Generally, a design specification will encompass gas, water and fire resistance along with specified chemical resistance. However any reputable seal manufacturer should be able to furnish evidence regarding the expected lifespan.

Key to an effective seal

Training and preparation – read and follow manufacturers instructions. This requires knowledge and skill.
Sealing system selection – most underground duct sealing systems will need to block water and gases and tolerate hydrocarbons. If the duct enters the building, a fire stop may be required so you need to select a sealing system that addresses the risk present.
Cable separation – this is a area where most duct seals will fail ; either the product doesn’t support cable separation, or the installer has been unable to separate the cable sufficiently. Without separation, water and gases will simply wick through areas without the sealant.
Conduit sealing – our range of conduit sealing systems have been designed to provide a simple and effective solution for watertight and gas sealing of pipes and cables in conduits, boreholes and ducts. Conduit sealing systems can be installed horizontally and vertically; they are very flexible.

Key Benefits of using an effective Duct seal

Allows for low density foam to use
Used in many places .
Made of good quality polyurethane foam material

Duct sealing and sealing products manufactured by Filoform 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.