Extended EJOT DDS‑Z Fixings Make Deep Soffit Insulation Faster and Easier to Install

EJOT UK has expanded its UK‑exclusive DDS‑Z concrete screw range to support the efficient installation of significantly deeper soffit liners, helping contractors meet ever‑increasing thermal, fire and acoustic performance demands.

The extended DDS‑Z fastener range enables installers to securely fix thick soffit insulation while requiring a concrete embedment of just 25mm, even at greater fixing lengths. This shallow embedment allows the fastener to anchor reliably into concrete without increasing the risk of striking reinforcement, simplifying installation and reducing on‑site complications.

Fasteners in existing lengths of 275, 300, 325 and 350mm are already widely used on projects where enhanced performance is critical, including car parks, undercrofts and other unheated spaces located beneath residential or commercial buildings. In these applications, achieving compliance with stricter building regulations often means installing much thicker soffit insulation, frequently using non‑combustible mineral fibre boards to provide improved thermal efficiency and fire resistance.

With current DDS‑Z fixings already facilitating soffit insulation depths of up to 325mm, EJOT’s latest range extension pushes capability even further. A new 400mm DDS‑Z fastener, scheduled for launch by the end of Q1 2026, will allow insulation thicknesses of up to 375mm to be installed using the same streamlined fixing method.

Despite the increased lengths, all DDS‑Z fixings continue to rely on the same 25mm concrete embedment. As the screw does not expand during installation, it is particularly well‑suited to use with pre‑stressed concrete beams, offering a safer and more predictable fixing solution while helping to control installation time and project costs.

The DDS‑Z system combines a high‑performance concrete screw with the EJOT DD‑T washer, creating a fixing designed specifically for securing ceiling insulation and acoustic panels to concrete soffits. Manufactured from steel with a durable duplex coating, the self‑tapping fastener is suitable for both cracked and non‑cracked concrete and achieves a C1–C3 corrosion resistance rating, ensuring long‑term durability.

Richard Bowhay, Sales Manager for Construction Fasteners at EJOT UK, commented:

“Recent updates to the Building Regulations, along with the industry’s focus on achieving Net Zero Carbon, have placed renewed emphasis on soffit insulation performance. While fire safety and thermal efficiency remain top priorities at specification stage, acoustic performance is now equally critical in many developments.”

“As a result, we are seeing thicker insulation specified across both new‑build and refurbishment projects. However, these performance gains must be balanced with practical considerations such as installation speed, visual finish, durability and overall cost. Choosing the right fixing solution is therefore essential.”

“Fixings need to be simple to install while providing secure, long‑term performance throughout the lifespan of the soffit system — and that’s exactly what the DDS‑Z range delivers.”

Combining strength, reliability and ease of use, the EJOT DDS‑Z offers specifiers and installers a dependable solution backed by EJOT’s quality assurance. To help projects achieve the optimum balance of performance and value, EJOT’s technical team can also provide early‑stage advice to insulation manufacturers and contractors, ensuring soffit systems meet regulatory and environmental targets without adding unnecessary complexity or cost.