• Two-part fixing: a steel screw with a hinged cover cap that clips shut over the head.
• Black cap seals against water ingress at each fixing point.
• Fixes through the crown of the corrugation, the raised top that sheds water.
• Made for plastic corrugated sheets, including PVC, polycarbonate and bitumen.
• Fastens sheets to timber purlins and rails on light roofing jobs.
• Neat result, since the closed cap hides the screw head.
• Also sold with a clear cap if you would rather the fixing blend into lighter sheets.

These fixings suit any job where plastic corrugated sheets meet a timber frame. Common uses include:

• Corrugated roofing on garden sheds and workshops.
• Carports, lean-tos and canopies.
• Log stores and open-fronted stores.
• Agricultural and smallholding buildings.
• Repairs and re-covers on existing plastic sheet roofs.

• Brand: TIMCO
• Type: Screw with hinged cover cap
• Cap: Clear plastic (hinged, sealing)
• Material: Steel screw
• Fixes through: Crown of corrugation
• Substrate: Plastic corrugated sheet to timber
• Seals: Yes, against water ingress
• Sizes: 10 x 3, sold in bags
• Use: Corrugated roofing (clear/translucent sheets)

Do you fix through the crown or the valley of a corrugated sheet?

Fix through the crown, the raised top of each corrugation. That keeps the fixing on the high point where water runs off, so the sealed cap has the best chance of staying dry.

Are these for plastic or metal corrugated sheets?

They are made for plastic corrugated sheets such as PVC, polycarbonate and bitumen, fixed to timber. For metal profile sheets you usually want self-drilling roofing screws with a washer instead.

How many fixings do I need per sheet?

As a rough guide, fix through the crown at every purlin and space the fixings across the sheet width so it cannot lift. Patterns vary with span and exposure, so follow the sheet manufacturer's fixing guidance for your roof.

Do the caps actually stop leaks?

The hinged cap snaps over the screw head and presses down to seal that point against water ingress. Fixing through the crown and not overtightening the sheet both help keep it watertight.

What colour options are there?

This version has a black cap. TIMCO also make the same fixing with a clear cap, so you can match the fixing to the sheet colour.

What size are they and how are they sold?

They come in sizes such as 10 x 3 inch and are supplied in bags, for example 50 per bag. Check the size against your sheet thickness and the depth of your timber.