Abstract: A waterproof and airtight double-sided pressure-sensitive adhesive tape includes a substrate and a pressure-sensitive adhesive layer on the both surfaces thereof, wherein the substrate is a rubber-made sheet; and the surface of at least one of the pressure-sensitive adhesive layers is protected by a release liner having elongation properties. It is preferable that the rubber-made sheet as the substrate has an elongation at the time of breakage (distance between two gage marks: 40 mm, drawing rate: 300 mm/min) of from 200 to 1,200% in both the longitudinal direction and the cross direction and a stress under 100% elongation (distance between two gage marks: 40 mm, drawing rate: 50 mm/min) of from 10 to 100 N/cm2 in both the longitudinal direction and the cross direction.

Abstract: A waterproofing execution method of a three-plane crossing structure by means of an extensible waterproofing and airtight pressure-sensitive adhesive sheet including sticking the extensible waterproofing and airtight pressure-sensitive adhesive sheet to a peripheral part of three-plane crossing including a point corner part which comes into contact with three planes in a three-plane crossing structure having the three planes wherein the three planes come into contact and respective planes of the three planes also come into contact with each other and peripheral parts thereof includes the processes (A) to (E) as described in the specification.