Installing fitting upvc window with Trufit installation tape

The UK is on a critical journey towards net zero, with energy-efficient homes at the forefront of this national effort. Buildings account for a staggering 39% of global carbon emissions, making high-performance windows and doors essential components in reducing this footprint. Window technology has evolved at a rapid pace, with triple glazing, thermal breaks, and low-emissivity glass becoming standard. Yet, these advanced products are often let down by an outdated and overlooked final step: the installation seal.

For decades, silicone sealant has been the default choice for window fitting, primarily due to its low cost. However, as building standards tighten and energy costs soar, it’s clear that traditional silicone is no longer fit for purpose. It creates a weak link in the building envelope, undermining the performance of even the most expensive windows. This article explores the hidden costs of relying on silicone and introduces a modern, high-performance alternative: expanding window installation tape.

The Hidden Costs of Traditional Silicone Installation

While familiar, silicone sealant presents significant challenges that directly impact an installer’s productivity, profitability, and professional reputation.

Poor Thermal & Airtight Performance: Silicone offers poor thermal insulation and is prone to shrinkage and cracking over time. This creates gaps that lead to drafts, heat loss, and moisture problems, directly contradicting the goals of an energy-efficient installation and failing to meet modern airtightness standards.
Weather-Dependent Application: Applying silicone is a fair-weather job. Wind, rain, and cold temperatures make it extremely difficult to achieve a clean, effective seal, leading to costly and frustrating project delays, especially during UK winters.
Installation Inconsistencies: Even with a skilled hand, achieving a perfect silicone bead is challenging. The finish can be messy and inconsistent, and it is liable to become dirty and discoloured over time, detracting from the overall quality of the window installation.
Durability and Callbacks: Silicone is not a “fit and forget” solution. It degrades under UV exposure, loses flexibility, and can detach from uPVC frames, leading to premature failure. These failures result in costly callbacks, warranty claims, and damage to a fitter’s hard-earned reputation.

Installation: The Missing Link in Window Performance

The performance gap between a window’s advertised U-value and its real-world efficiency is often decided at the perimeter seal. A poor installation can increase a home’s heat loss by up to 30%, negating the benefits of high-spec glazing.

Under the latest UK Building Regulations, airtightness is no longer optional. New dwellings must now achieve an air permeability rate of 8 m³/hr.m² @ 50Pa or less, with every single property subject to testing. Traditional sealing methods make achieving this standard a significant challenge. An airtight seal is critical not only for compliance but also for delivering genuine energy savings and preventing issues like condensation and mould, which are major concerns for homeowners.

For professional installers, the quality of the seal is directly linked to customer satisfaction. A perfectly fitted window that eliminates drafts and reduces energy bills generates positive reviews and word-of-mouth referrals—the lifeblood of any successful trade business.

TruFit: The Superior Installation Solution

To bridge this performance gap, installers need a solution that matches the sophistication of modern windows. TruFit expanding installation tape is an advanced, high-performance alternative designed for the 21st century.

Made from a high-density, open-cell polyurethane foam impregnated with a flame-retardant resin, TruFit is applied to the window frame before installation. Once the window is in place, the tape slowly expands over 24 hours to completely fill the gap between the frame and the aperture, creating a permanent, highly effective seal.

Key Performance Specifications:

Exceptional Thermal Insulation: Provides a U-Value of just 0.048 W/m²K, virtually eliminating thermal bridging around the frame.
Weatherproof Seal: Achieves a minimum of 600pa resistance to driving rain, withstanding even the most unpredictable British weather.
Extreme Temperature Resistance: Performs flawlessly in temperatures ranging from -30°C to +90°C.
Acoustic Insulation: Delivers impressive sound reduction of 45dB, adding value for homeowners in noisy urban environments.

Compared to silicone, TruFit offers a faster, cleaner, and more reliable installation every time. It eliminates guesswork and provides a consistent, high-quality seal that ensures the window performs as designed.

How to Install Windows with TruFit

Using TruFit streamlines the installation process, allowing fitters to work more efficiently without compromising on quality.

Prepare the Opening & Frame: Ensure the wall opening and the sides of the window frame are clean and free of debris.
Apply the Tape: Fix the self-adhesive TruFit tape to the window frame, setting it back 2mm from the face of the joint. The charcoal-grey side should face inwards.
Manage Corners: Tightly butt-joint the tape at all corners, allowing 10mm of extra material per metre. Any small gaps can be sealed with a low-modulus joint sealant.
Position the Window: Lift and fix the new window into the aperture using either through-frame fixing or distance mounting, depending on the wall construction.
Let it Expand: TruFit will continue to expand over a 24-hour period, creating a perfect, airtight, and weatherproof seal around the entire perimeter.

Why Professional Installers are Switching to TruFit

For window fitting businesses, the advantages of adopting modern installation tape are clear and compelling.

Boost Productivity: Installation with TruFit is significantly faster than using silicone. Because it can be used in any weather, it eliminates costly delays, allowing teams to complete more jobs and increase revenue.
Enhance Quality & Reputation: The self-expanding nature of the tape ensures a perfect seal every time, dramatically reducing the risk of faults and expensive callbacks. This consistency builds a reputation for quality and reliability.
Gain a Competitive Edge: Offering a superior installation method provides a valuable unique selling point. It demonstrates a commitment to quality and energy efficiency that resonates with today’s discerning homeowners.
Future-Proof Your Business: As building regulations become even stricter, TruFit ensures your installations are already compliant with the highest standards for airtightness and thermal performance, future-proofing your work.

Transform Your Window Installations Today

The evolution of window technology demands an evolution in installation practice. Relying on outdated silicone sealants undermines the performance of premium products and leaves installers vulnerable to callbacks and weather delays.

TruFit window installation tape offers a modern, reliable, and highly effective solution that guarantees a perfect seal every time. By embracing this technology, professional fitters can enhance their productivity, improve customer satisfaction, and build a reputation for excellence in an increasingly competitive market.

To learn more about how TruFit can transform your business and to find a local supplier, contact Edgetech today.