INTRODUCING
DOR CAV
™
The Dor Cav is a structurally-rated glass reinforced plastic (GRP) cavity closer designed to support insulation and screed across a cavity wall, specifically beneath an external door opening.
Developed to replace previous methods such as concrete infill or timber packing, Dor Cav provides a consistent, compliant solution that improves both structural performance and thermal efficiency.
With larger cavities now being specified in modern construction, ensuring a reliable and thermally efficient threshold solution has never been more important.
STRUCTURALLY DESIGNED
The Dor Cav cavity closer is precision-engineered to support imposed loads across cavity walls at external door thresholds, including insulation, screed and typical foot traffic.
Developed in accordance with EN 1991-1-1:2002 (Eurocode 1 – Actions on structures) and tested to BS EN 13706 for fibre-reinforced polymer structural profiles, the Dor Cav delivers consistent strength, durability and reliable long-term performance. This ensures a compliant and dependable alternative to traditional infill methods.
QUICK INSTALLATION
Designed for rapid and efficient on-site installation, Dor Cav is lightweight, easy to handle and can be quickly cut to size, allowing for accurate fitting across a range of door opening widths.
Its simple installation method reduces the need for additional materials or complex preparation, helping to streamline the build process. This not only saves time on site but also reduces labour costs and minimises reliance on traditional cavity infill methods such as concrete or timber.
NO COLD BRIDGING
Dor Cav maintains insulation continuity across the cavity, preventing thermal bridging at the door threshold – a key junction between the internal floor and external wall.
Traditional methods such as concrete infill or timber packing create direct thermal bridges, increasing heat loss and reducing overall energy efficiency. By providing a dedicated insulated solution, the Dor Cav cavity closer helps improve thermal performance and supports compliance with Part L of the Building Regulations, contributing to more energy-efficient, lower carbon homes.
UK MANUFACTURED
All of our products (Dor Cav, Bloc Seal and Insu Clip) are manufactured in the UK and hold certifications for both ISO9001 (Quality Management) and ISO14001 (Environmental Management), guaranteeing their quality and adherence to environmental best practices.
This ensures consistent product performance and dependable supply for construction projects, while supporting responsible sourcing and manufacturing standards across the UK.
SEE IT IN ACTION
FAQ
Dor Cav is designed for cavity widths between 75mm and 150mm, making it suitable for a wide range of modern residential wall constructions.
The required length should match the width of the door opening, or the nearest available size above; for example, a 900mm door opening would typically use a 1000mm Dor Cav, which can then be cut down on site to achieve an accurate fit.
Dor Cav is available in 1000mm, 1800mm and 2400mm lengths, and for wider openings, units can be combined; for example, a 3200mm opening can be bridged using one 2400mm unit and one 1000mm unit.
The Dor Cav is installed beneath the insulation and screed at the door threshold, spanning the cavity to provide structural support; for full installation details, including positioning and fixing, please refer to the installation guide
A dedicated retrofit installation guide is available, outlining the correct method for installing the Dor Cav into existing structures; please refer to the retrofit installation guide for full details.
No, Dor Cav is specifically designed to sit beneath the insulation and screed, where it provides structural support across the cavity, and it is not suitable for installation at finished floor level or above the floor build-up.
No, Dor Cav is designed to span the cavity and support the insulation and screed without the need for additional infill materials such as concrete or timber.
Yes, by maintaining insulation continuity and eliminating thermal bridging at the threshold, Dor Cav supports compliance with Part L of the Building Regulations and contributes to improved energy performance.
Dor Cav is manufactured from GRP, a durable composite material that provides high strength, low thermal conductivity and long-term resistance to moisture and degradation.
BUY NOW
Dor Cav
The Dor Cav is a ground-breaking GRP structural cavity closer designed to support insulation and screed across cavity walls beneath external door openings. Developed as a purpose-built alternative to traditional infill methods, it provides a consistent, reliable solution where structural performance and thermal efficiency are critical. By eliminating the need for concrete or timber infill, Dor Cav helps reduce installation time on site while maintaining insulation continuity at the threshold. This makes it an ideal choice for modern construction projects working with wider cavity widths and stricter energy performance requirements.
ADDITIONAL PRODUCTS
BLOC SEAL
Bloc Seal provides a secure and compliant way for underground utility services to enter a property within a beam and block floor system, helping to prevent air leakage and moisture ingress while maintaining the integrity of the floor structure.
Find out more
INSU CLIP
Insu Clip provides a fast and effective way to securely fix perimeter insulation upstands in place without penetrating damp proof membranes, helping to maintain airtightness and protect the integrity of the building envelope.
Find out more