Snap fastener for sheet material

A method of releasably securing a sheet of material to an underlying surface, the method comprising:

• affixing an elongated first fastener section having upwardly extending first section sidewalls to the underlying surface;
• arranging the sheet of material over the first fastener section;
• and
• connecting an elongated second fastener section having downwardly extending second section sidewalls to the first fastener section such that the sheet of material is secured between interlocking engagement arms and engagement portions of the first and second fastener sections;
• and
• wherein the underlying surface is a roof of a first pre-fabricated modular building section and arranging the sheet material includes arranging the sheet material over a mate line between the first pre-fabricated modular building section and a second pre-fabricated modular building section.

A snap fastener comprising:

• a first fastener section having a first section central portion with a pair of upwardly extending first section sidewalls located along opposite first section edges thereof, each sidewall including an inwardly extending engagement arm;
• and
• a second fastener section having a second section central portion with first and second downwardly extending second section sidewalls located along opposite second section edges thereof, respective first and second engagement portions being connected to the first and second second section sidewalls by inwardly extending first and second legs, the first leg extending inwardly generally perpendicular to the first sidewall and the second leg curving inwardly and downwardly from the second sidewall, the first engagement and second engagement portions including respective first and second outwardly-extending protrusions, the second protrusion extending outwardly to a greater extent than the first protrusion, the second fastener section including a lip overhanging the first second section sidewall;
• wherein the first and second fastener sections are releasably connectable to secure a sheet material therebetween by securing the first and second engagement portions under the engagement arms of the first section sidewalls, with the first second section sidewall extending upwardly from one of the first section sidewalls, such that the lip is spaced vertically apart from the secured sheet material.