How To Lay Bitumen Roof Sheets

Lay the individual sheets across the roof joists or cross beams.

How to lay bitumen roof sheets.

Seal the top of the roofing completely. Secure the sheets to the roof by using stainless steel fasteners. It is important to start laying the sheets at the opposite end of the roof to the prevailing winds to prevent the side laps from facing into the wind which could cause uplift and water ingress. Seal the sides of the corrugated bitumen sheets with foam strips or spray foam.

If you have a short parapet wall you can usually roll the roofing sheets up onto it. Start alternate courses of sheets with a half width sheet. The sheets cannot make a tight turn so there should be flashing or built up roofing in the corners so the roofing can make a gentle sweeping turn upward. Secure the edge of the sheet at the gutter end every second corrugation.

This forms a broken bond sheet pattern thus avoiding a 4 ply sheet thickness build up at the corners of sheets. When laying sheets if they are corrugated allow a minimum of one corrugation and stagger the sheets using half a sheet to start the second course. Follow manufacturer s instructions for the sealant application. Position and fix an additional purlin at the ridge to take ridge fixings.

Make sure you space these fasteners every three to four corrugations. Align the next sheet of modified bitumen roofing so it covers the edge of the first sheet by a few inches and repeat the process. If you ve got a pergola attached to your house then you might want to give yourself some extra shelter and protection from the weather simply by installing. Trim any excess with shears.

This helps in setting up the lap of the panels. Once you see bubbles forming gently roll the roofing forward with your foot to install.