Screening 81 Openings Inside a Curved CLT Structure, Surrey

Construction Screens

Screening 81 Openings Inside a Curved CLT Structure, Surrey

Key Facts

• Location: Windlesham, Surrey
• Structure: Cross-laminated timber (CLT) residential building
• Scope: 81 individual screened openings across three floor levels
• Total area: Approximately 1,169m²
• Material: Rhino Shrink Wrap 300 micron FR, EN13501, white
• Technique: Double timber batten trap and screen system
• Duration: Approximately 17 days across three phases, March to April 2025

The Problem

Cross-laminated timber construction presents a different screening challenge to a conventional concrete or steel frame. The structure on this Surrey residential scheme was built almost entirely from CLT panels, with a distinctive curved facade and balcony geometry that produced dozens of irregular, non-repeating openings across three floor levels rather than the regular grid of a typical frame: 18 on the lower ground floor, 32 on the upper ground floor and a further 31 on the ground floor, 81 in total.

Each opening needed a fire-retardant screen for weather exclusion and site security during the build, but a CLT structure adds a constraint a concrete frame does not have: nothing can be fixed directly through the exposed timber that would compromise the finished surface or the building's fire strategy. The screening method needed to hold a drum-tight membrane across openings of widely varying size, some under a metre wide and others close to seven metres, without relying on fixings into the structural timber itself.

The Solution

Rhino 300 micron fire-retardant film, certified to EN13501, was specified across all 81 openings, installed using a double timber batten trap and screen system rather than a fixed or adhered membrane. A first run of C24 timber battens was fixed around the perimeter of each opening, to the floor and ceiling via coach screws and concrete screws, with galvanised L-brackets at the verticals rather than fixings into the CLT itself, plus a foam run to help seal the perimeter.

The film was then trapped against this first batten run and heat-shrunk drum tight, before a second trapping batten run was fixed directly over the membrane's edge, mechanically locking it in place along the full perimeter rather than depending on the shrink alone to hold it under tension. For any opening spanning more than 3m, additional triple timber uprights and a cross brace were installed mid-span. This reinforcement stops a wide sheet of trapped film moving or billowing under wind load, which becomes a real risk once a screen gets much beyond scaffold-bay width.

The work was phased across the building over three visits, with lower ground and upper ground floors first, and ground floor second. This allowed each level to be screened as it became accessible rather than waiting for the whole structure to be ready at once.

The Result

All 81 openings across three floor levels were screened over a phased programme of roughly 17 days between March and April 2025, using a fixing method that never required a single fixing into the CLT structure itself. The double-batten trap system gave a drum-tight, weathertight membrane at every opening, from the smallest sub-metre bay to spans approaching seven metres, with the mid-span bracing keeping the larger screens stable rather than working loose under wind.

For CLT and mass-timber projects specifically, this is the specification question worth asking early: a screening method has to protect the finished timber surface as much as it protects the opening, and a mechanically trapped membrane, rather than one fixed through the structure, is what makes that possible without compromising the building underneath it.

Specifying construction screens for a CLT or mass-timber structure?

Talk to the Rhino team about fixing methods that protect the finished timber.

Talk to the Rhino team