Our R&D team started the development of Siderise CT Cavity Tray in response to the government’s 2018 amendments to the Building Regulations in England banning the use of combustible materials in the external walls of high-rise residential and other ‘relevant’ buildings, unless installed between two leaves of masonry (Regulation 7 (3) (a). 

We engaged with contractors and industry bodies such as the BBA and NHBC to understand what the market really needed. We determined that the solution had to provide a high-performance and practical innovation for masonry external leaf and steel-framed backed walls that would comply with the forthcoming legislative changes. 

It also had to complement our EW Cavity Barrier and Firestop products for a systemised approach to passive fire protection and moisture management within the cavity. 

After plenty of research, development, and prototyping, we launched the unique Siderise CT Cavity Tray in September 2021. 

Combined passive fire protection and moisture management

Siderise CT Cavity Tray and all necessary ancillary components can be supplied as part of a complete masonry system package with Siderise EW Cavity Barrier and Firestop for compartmentation and BB-FB Balcony Bracket Fireboard for balcony connector encapsulation.

Fire

Siderise CT Cavity Tray has an A2-s1, d0 reaction to fire classification to EN 13501-1, which incorporates the DPC layer and satisfies the requirements of Regulation 7(2).

Buildability

Space can be severely constrained and over-congested with cavity barriers, thermal insulation, and structural restraints like masonry support systems at the slab edge. Siderise CT Cavity Tray can be cut and shaped tightly around masonry supports and detailed around other tricky interfaces then resealed with foil tape - helping to resolve junction clashes without compromising performance.​ 

Additionally, it is not necessary for CT Cavity Tray to sit in direct contact with the horizontal cavity barrier. To accommodate congestion and clashes, it can be positioned up to 225mm above the barrier i.e. 3 courses or 1 soldier course of brickwork.

Unlike its competitors, CT Cavity Tray removes the need for costly made-to-order prefabricated stainless-steel corners and reveals altogether.

For jointing at details such as corners or windows, a cutting knife and sealing tape is all that is needed - plus it cuts easily to accommodate architectural appeal. 

Speed 

Siderise CT Cavity Tray design streamlines installations by saving time compared with site-fabricated solutions that need specialist equipment, isolated onsite workshop zones and large site storage facilities.  

Test installations conducted with Hugh Baird College, Liverpool, found that it yielded an installation rate of up to 100m an hour. 

This time-saving design can have a big impact on project schedule efficiency, especially on larger projects with multiple floors and where different trades need to share mast usage. In fact, on the recently completed Anchorage project in Salford, it enabled the contractors to free up mast usage, with an estimated ratio of 70/30 in the bricklayers’ favour, speeding up the build programme. This led to the project team described it as a ‘game-changer’ that ‘does what it says on the tin.’  

Check out the full case study video at: https://youtu.be/Fl5LSMAw1bg   

BBA certified

BBA Agrément certification demonstrates that Siderise CT Cavity Tray meets the requirements of UK building and CDM regulations, and that it has been assessed to provide durability for the lifetime of the building when installed and maintained in accordance with the details given in the certificate.

Comprehensive assessment criteria included behaviour in relation to fire and compressive load, resistance to the passage of water, use with cavity wall insulation, joint watertightness, mortar adhesion, temperature cycling, accelerated ageing and additional advanced weathering testing.

Low temperature, adverse weather conditions, robustness in relation to falling debris, and compatibility with building materials were also considered, whilst the component materials that comprise CT Cavity Tray were evaluated through shear and flexural strength testing.

Jamie Hoskinson, Owner & Director, Kinlan 

"it's easier to work with. There's no soldering. There's less cutting, so you don't have to cut it in a workshop - you can cut it out in the area where you're actually building it."

Dynamic DWG Blocks

Siderise CT Cavity Tray Dynamic DWG Blocks provide a reusable CAD solution that helps designers work more efficiently and consistently across projects.

The blocks are adjustable, which allows users to modify sizes and positions within the product’s manufacturing parameters, removing the need to redraw whilst helping save time and maintaining accuracy.

Available in 2D section, elevation and plan views with accompanying example masonry façade details, the blocks support improved visualisation, coordination and design development. Embedded links give direct access to relevant product information and technical guidance, helping users access the latest supporting content while enabling the reuse of coordinated product solutions across multiple projects.

CT Cavity Tray Dynamic DWG Blocks are included in the Siderise Masonry Specification Pack, alongside blocks for Siderise EW Cavity Barrier and Firestop and Siderise BB-FB Balcony Bracket Fireboard, providing a coordinated set of Siderise masonry product details to support design development.

Building movement 

Siderise CT Cavity Tray’s insulation core and flexible attributes enable it to accommodate site tolerances and flex with movement of the steel frame, ensuring integrity and continuity of weatherproofing over the building’s lifetime. 

Thermal conductivity

We can provide thermal conductivity values for the insulation component of Siderise CT Cavity Tray, which can support thermal calculations and condensation risk assessments in relation to the energy efficiency requirements of the Building Regulations.

Compared to rigid trays formed from lead, zinc or stainless steel, CT Cavity Tray has lower thermal conductivity properties, therefore can contribute to reducing linear thermal bridging at critical junctions or interfaces with metal components in line with Approved Document L - Dwellings, Requirement L1A, paragraph 4.16.

Thermal continuity

Siderise CT Cavity Tray can help maintain thermal continuity within the cavity thanks to its insulation-filled triangular prism design. Achieving a fully insulated detail with traditional sheet trays can be difficult as their use can form an uninsulated void behind the drainage layer thus leading to localised uninsulated zones within the external wall construction. CT Cavity Tray on the other hand, occupies this void.

Thermal modelling

To better understand the thermal performance of Siderise CT Cavity Tray and EW Cavity Barrier and Firestop details within representative wall constructions, we commissioned an independent Energy Consultant to undertake a thermal modelling study.

The results showed that the calculated heat loss for CT Cavity Tray, within the specific junction details assessed, was lower than that for the example comparative stainless steel and zinc cavity tray arrangements, and that the primary variable between the different scenarios modelled was the cavity tray material.

The findings relate solely to the specific construction details and assumptions used within the assessment and should not be considered representative of all wall constructions or project conditions.

Thermal performance should always be reviewed on a project-by-project basis by a suitably qualified thermal assessor or energy consultant. The magnitude of a linear psi value can only be measured in the context of a whole dwelling energy assessment.

Single source supply package 

As part of a 4-part component system, Siderise CT Cavity Tray comes with all the components needed to support a tested solution and effective installation: CT Cavity Tray Stop End, CT Cavity Tray Aluminium Foil Jointing Tape and CT Cavity Tray DPM Seal. These products should be ordered together - just ask our customer services team when placing an order.

We can also supply cavity barriers and firestops for compatible holistic performance. Working with a single supplier can help streamline the purchasing and logistics process along with technical and site services support. 

BSI Identify registered  

Product identifier QR codes that are linked to BSI UPINS are printed on the product to allow rapid access to specification, testing, installation, and maintenance information using the BSI Identify digital identification service.

Martin Cockram, Managing Director, Landmark Brickwork Ltd 

"We have used all the A1 and A2 systems that are available on the market at present and in our opinion the Siderise CT Cavity Tray is the easiest and quickest to install. The ease of installation makes it a more cost-effective option at present.

Costing for the system has been made simple as the tray is priced in cavity size ranges, the only addition to these rates is the cost of the tape required."