Lay metal sheets in runs. Start at the eaves and in the corner away from the direction of the prevailing wind. This will help prevent side laps facing into the wind and water ingress.
If the first sheet is not laid perpendicular to the eaves and ridge adjustments will need to be made when laying other sheets and a saw tooth effect will be seen. This may be unavoidable if the building is not square.
Top tip - When laying your first few sheets it may be helpful not to fully fix them until sure they are correctly aligned. This can help mitigate the impact of false starts! Once sure put the remaining fixings in and carry on.
Sheets should be overlapped by the next sheet in the run by at least one profile or corrugation [‘side laps’]. Adjacent runs of sheets should overlap each other by at least 250mm [‘end laps’].
The first row of sheets should extend over the bottom purlin and the eaves so that rainwater can drain into a gutter or beyond the wall.