Membrane Roof Minimum Slope

This 1 4 12 minimum roof slope requirement also applies to spray polyurethane foam spf roof systems in new construction.

Membrane roof minimum slope.

It is uncommon to find a roof below 15 but for those very low pitch applications there are interlocking clay pantiles available suitable for use down to 12 5. Minimum roof slope roof pitch r905 13 1. Roofing material or system. Traditionally a minimum roof pitch of 20 was recommended in bs 5534 but modern tiles and slates have now been designed for applications as low as 15.

It is best to drain the roof to one or two edges. They are permitted to be laid to a minimum slope of 1 5 for roofs and 1 slope for decking but with conditions see table 1. This applies whether the waterproofing is a polymeric single ply membrane a reinforced bitumen membrane or another type listed in bs 6229 2018 the code of practice for flat roofs with continuously supported flexible waterproof coverings. In 12 0 25 in 12 1 19 built up roof coal tar pitch.

Thermoplastic single ply membrane roofs must have a design roof slope of 1 4 12 or greater 2 slope. To achieve this a design fall of 1 in 40 or 1 in 60 is advised. Minimum required slope x in 12 minimum required slope degrees asphalt shingles. Two membrane roofing systems butyl rubber and epdm see table 1 comply with acceptable solution e2 as1.

Protection from rain and snow the finished roof should have a slope of at least 1 in 80. This means for every 12 horizontal units the roof must rise a minimum of one fourth vertical unit. 18 43 asphalt shingles with special underlayment requirements 2 in 12. Roofing type profile style minimum pitch conditions e2 as1 compliant.

The following general guidance can be confirmed by the specific membrane manufacturer. 9 46 built up roof asphalt. Minimum slope for a membrane roof when we say flat roof we don t mean perfectly flat which is undesirable since water still needs to be shed to roof drains. Minimum required roof slope for roofing materials.

For example the international building code 2018 edition ibc 2018 prescribes a 1 4 12 minimum roof slope for asphalt built up polymer modified bitumen thermoset and thermoplastic single ply and liquid applied membranes in new construction.