Marking Out

• A pencil of any colour may be used except black or so-called lead pencils.
• Use a string line with chalk dust, or a fine, felt-tipped marker.

End of Sheets

Why are end of sheets treated?

Ends of sheets are treated to maximise weather resistance, environmental protection and vermin resistance.

At the high end of roofing, wind can drive water uphill, under the flashing or capping and into a building, so turn-ups are used to minimise the problem of water being driven uphill and under the flashing or capping and into a building:

The turning down process prevents water running up the underside of flat trays in low sloped roofs as a result of wind or capillary action. Valleys (or pans) must be: