Description

Key Features

• Suitable for 10mm twinwall, 16mm triplewall and 25mm multiwall polycarbonate sheets.
• Aluminium base designed for fixing onto supporting timber rafters.
• White PVC top cap with snapdown locking positions to suit the sheet thickness.
• EPDM rubber gaskets help seal against the polycarbonate.
• Supplied with one end cap per complete glazing bar unit.
• Suitable for timber-supported lean-tos, carports, pergolas, canopies and shelters.
• Designed for multiwall polycarbonate; not suitable for glass.

Choosing the Right Bar for 25mm Sheets

This 10mm–25mm glazing bar accepts 25mm polycarbonate. However, for a new installation using 25mm sheets, we recommend the Sunwood White Snapdown Rafter Glazing Bar (25mm–35mm).

The 25mm–35mm version allows the PVC top cap to engage at a lower locking position within the aluminium base when fitted over 25mm sheets. Choose the bar before calculating and ordering your roofing materials, and use its matching end caps.

Supporting Rafters

This is a rafter-supported glazing bar. It must be supported continuously along its length and securely fixed to a suitable timber rafter at least 50mm wide.

The glazing bar holds the sheets at their supported edges; it does not replace the structural framework beneath the roof. Rafter spacing must also suit the thickness and dimensions of your polycarbonate sheets.

Preparing the Rubber Gasket

The supplied rubber gasket is joined together and must be split before installation.

Separate it along the joining line to form two individual strips, then fit one strip into each side of the aluminium base. Check that both strips sit evenly along the bar before positioning the sheets. Do not install the gasket while the two strips are still joined.

Calculating Your Sheet Sizes

Polycarbonate expands and contracts as temperatures change, so sheets must have sufficient clearance within the glazing bars. Do not force a sheet tightly against the central upstand.

For the arrangements covered in our sizing guide, allow 10mm off each sheet edge that meets a glazing bar. A sheet between two glazing bars therefore requires a total deduction of 20mm from the rafter centre-to-centre measurement.

Where the outer edges are finished with F-sections instead of end glazing bars, the end-sheet calculation differs. Read our glazing bar deductions and sheet sizing guide before ordering cut-to-size sheets.

Installation

1. Check the framework. Ensure the supporting rafters are secure, correctly spaced and wide enough to support the glazing bars fully.
2. Cut the bar to length. Prepare the aluminium base and PVC top cap, removing any burrs or loose cutting debris.
3. Separate and fit the gasket. Split the joined rubber gasket into two strips and fit one into each side of the base.
4. Fix the aluminium base. Secure it to the timber rafter using suitable exterior-grade fixings selected for the supporting timber and installation. Follow the product’s fitting instructions for fixing positions and spacing.
5. Position the sheets. Rest the prepared polycarbonate sheets evenly on the gaskets, maintaining the required expansion clearance.
6. Fit the PVC top cap. Press it evenly into the correct locking position for your sheet thickness. Check that it is engaged consistently along the full length.
7. Fit the end cap. Check the cut ends are clean and aligned, then fit the supplied cap to the exposed bar end.

Do not strike the PVC top cap with a rubber mallet, as this can cause stress fractures. If the cap will not engage, check the sheet thickness, gasket position and alignment before continuing.

End Caps and Finishing Accessories

Each complete glazing bar unit includes one end cap. If you cut a bar into separate usable lengths or need to finish another exposed end, order additional matching Sunwood white end caps separately.

Glazing bar end caps finish the bars themselves. The open flute ends of your polycarbonate sheets require their own sheet closures and appropriate aluminium sealing tape and anti-dust breather tape. Select these to match your sheet thickness and follow our sheet closure installation advice.