EPDM measuring guide
How to measure a flat roof for EPDM
Measure the roof before choosing a membrane or complete roof kit. Use maximum dimensions and record every detail that changes the material requirement.
Measurements to record
- Measure the maximum roof-deck length.
- Measure the maximum roof-deck width.
- Measure all upstands and wall junctions.
- Record outlets, pipes, rooflights and internal or external corners.
- Identify the roof-deck material.
Roof-deck area
Multiply the maximum length by the maximum width to calculate the rectangular deck area. This area alone is not the finished membrane size because perimeter, upstand and detailing allowances may also be required.
Irregular roofs
Split an irregular roof into simple rectangles, measure each area and add them together. Do not deduct openings until the membrane layout and detailing method have been confirmed.
Before ordering
Check the selected product’s listed dimensions and installation requirements. Cut-to-size membrane may not be returnable once prepared for the order.