How to Create a Temporary Shrink Wrap Roof

A temporary shrink wrap roof creates a continuously waterproof cover over a scaffold structure, faster to install than corrugated sheeting, lighter than a proprietary roof system, and fully adaptable to irregular or awkward roof shapes.

This guide covers the planning, scaffold requirements and installation process for temporary shrink wrap roofs. For the side elevation installation process, hanging, welding and shrinking scaffold wrap on vertical faces, see the companion guide.

Read: How to Shrink Wrap a Scaffold

Materials and Equipment

Shrink Wrap Film

For temporary roof applications, 300 micron white flame retardant film is the standard specification, the same gauge used for scaffold side elevation work. The roof sheet experiences significant wind load and UV exposure, and the heavier gauge provides the durability required.

Flame retardant certification to EN13501 is the baseline for commercial sites. LPS1207 and LPS1215 certification is required on some projects, so confirm the specification before ordering. Film for roof applications is typically 12m or 16m wide to minimise the number of joins across the roof span. Allow approximately 10% extra per roll for wastage from overlaps and joins.

Shop: Scaffold Shrink Wrap Film

Read: Shrink Wrap Film Buying Guide

Heat Gun

The propane gas heat tool is used to weld the roof sheet to the side sheets and to heat shrink the cover drum tight. It must have a dead man's trigger and connects to a propane cylinder via a hose and regulator. Only trained operators should use the heat tool.

Shop: Shrink Wrap Heat Guns

Read: Heat Gun Buying Guide

Battens and Roofing Foam Strip

Timber battens, typically 50mm x 25mm, are screwed through the shrink wrap film into the scaffold boards beneath at approximately two-metre intervals across the roof. The batten prevents wind uplift on large roof sheets. Without it, wind loading creates significant upward force. Roofing foam strip is placed between the batten and the film as a gasket, preventing water ingress through the screw holes.

Patch Tape

100mm wide patch tape is used to reinforce welds, repair holes and seal around batten fixings. Use a tape with a synthetic rubber adhesive and UV inhibitor. Cut with a knife rather than tearing.

Shop: Shrink Wrap Tape

Read: Shrink Wrap Tape Buying Guide

Welding Gauntlets and Sleeve

Leather welding gauntlets are required for all hot works. A leather welding sleeve provides additional protection to the upper arm during welding and shrinking. Both must be worn for the full duration of heat tool use.

Shop: Welding Gauntlets

Planning a Temporary Roof

When is shrink wrap suitable for a temporary roof?

Shrink wrap is best suited to small and medium-sized temporary roofs and to awkwardly shaped structures where a proprietary system roof would be difficult to configure. For very large roofs, particularly major refurbishment or construction projects, a system roof such as Haki or Ubix may be more appropriate.

For the majority of commercial and residential temporary roof applications, shrink wrap is the faster and more cost-effective option.

The critical planning rule

For temporary roofs, do not start installing sheeting unless you can complete the entire roof section that day, including heat welding all joints and heat shrinking the complete area drum tight. A partially completed roof sheet left overnight, particularly in windy conditions, will flap and may be damaged beyond use by morning.

Plan the job around weather windows. Even light wind makes roof installation more difficult. Large sheets of film are difficult to control on an open roof surface in any meaningful breeze, and the heat shrinking stage requires calm air to work properly.

Scaffold roof requirements

The roof structure must meet specific requirements before shrink wrap installation begins. These are covered in full in the scaffold setup guide, but the key points for roofs are:

Roof pitch: a minimum pitch of 10%, or 1:10, is required to allow rainwater to drain off the surface rather than pool.

Perimeter handrail: a handrail around the full roof perimeter provides edge protection for the installation team and anchor points for safety lines. This is a health and safety requirement for working at height on an open roof surface.

Boarding: for medium-sized roofs, the roof structure should be fully boarded out to allow the installation team to access every part of the roof surface during welding and shrinking. For large roofs where full boarding is not practical, runs of boards three boards wide at two-metre centres are the minimum, with a perimeter board run around the roof edge.

The boards serve two purposes: safe access for the team, and anchor points for battening the sheeting at two-metre intervals to resist wind uplift.

Read: How to Prepare a Scaffold for Shrink Wrap

Installation: Sides First

Always shrink wrap the sides of the scaffold before installing the roof sheet. The roof sheet overlaps the top edge of the side sheets, and this overlap is then heat welded to create a continuous waterproof seal between the roof and the walls. Installing the sides first also creates a windbreak, which makes the roof installation significantly easier.

The side sheets are dropped to approximately 30-40cm past the lowest handrail and heat welded to the scaffold tube below. The top edge of each side sheet is left untreated at the roof level. It will be overlapped and welded by the roof sheet.

For side elevation installation in full, see the companion guide.

Read: How to Shrink Wrap a Scaffold

Installing the Roof Sheet

Unrolling and positioning

For wide roof spans, wider roll sizes are more efficient. 12m or 16m wide rolls reduce the number of joints needed across the roof. For smaller roofs or canopies, a standard 7m wide roll may be sufficient. Where multiple sheets are needed, the widths are heat welded together on the roof surface.

Position the roll stand at the ridge or one end of the roof so the film can be drawn across the surface as it unrolls. Do not drag the film across rough board surfaces. Carry or lay it carefully to avoid snagging on fixings or board edges.

Where roll sizes mean the film needs to be pulled up from ground level, tape the leading edge closed before lifting so it can be drawn up as a narrow strip. Once in position, the folds can be opened out.

Battening at two-metre intervals

Once the roof sheet is unrolled and positioned, it must be battened to the scaffold boards at approximately two-metre intervals across the roof. The batten prevents wind uplift. Without it, wind loading on a large roof sheet creates significant upward force.

Use roofing foam strip between the batten and the shrink wrap. The foam acts as a gasket, preventing water ingress through the batten screw holes.

Overlapping and welding to the side sheets

The roof sheet is drawn over the perimeter handrail and overlapped down the outside of the side sheets by 30-40cm. This overlap is then heat welded to the side sheet. The roof sheet sits on the outside of the side sheet, like the overlap of a roof tile.

At each corner, the film needs to be cut, folded and re-welded to create a neat, sealed corner junction.

Temporary roof cover installation

Step-by-step installation of a temporary shrink wrap roof cover over a scaffold structure.

Corners

How to cut, fold and weld shrink wrap sheeting at roof corners.

Shrinking the Roof

Shrinking a roof sheet follows the same process as shrinking side sheets. Hold the heat gun 30-40cm from the surface and work across the film using steady, consistent passes. However, roof shrinking has two additional considerations.

First, you must be able to reach the full surface safely. Work from the boarded access runs, not directly on the shrink wrap. The film is not a safe walking surface, particularly after shrinking when it is taut and slippery.

Second, be careful around batten fixings. Heating the film around a batten screw point can cause the film to thin at that location. Work around fixings rather than over them.

Shrink the roof in sections, completing each area before moving on. Do not go back over already-shrunk areas.

Small Roof Canopies

For small roofs and canopies, where the installation team has arm's reach access to the entire underside of the roof, no additional boarding is required within the roof structure, provided the boarded lift immediately below gives safe access.

This also applies to a canopy over the top lift of a scaffold. As long as the team can reach the full underside from the top boarded lift, no additional roof boards are needed.

The installation process for a small canopy follows the same sequence: side sheets first, roof sheet over, overlap and weld the perimeter, shrink drum tight.

Ready to Learn the Full Process?

This guide covers the planning, scaffold requirements and installation sequence for temporary shrink wrap roofs. The detailed installation technique, welding the roof sheet to side sheets, managing corners, shrinking method and working safely at height, is covered in the Rhino scaffold training course alongside side elevation installation, health and safety and working at height.

Related Guides

• How to Shrink Wrap a Scaffold - the companion guide covering side elevation installation: hanging, welding, shrinking and repairs.
• How to Prepare a Scaffold for Shrink Wrap - how to set up the scaffold structure correctly, including roof boarding requirements, pitch, perimeter handrails and battening anchor points.
• Scaffold Shrink Wrap vs Traditional Sheeting - a comparison to help you decide which is right for your project.