Adjustable roof membrane

DETAILED DESCRIPTION The present invention relates generally to roof-covering membranes, and more particularly, to an adjustable comer fitment and roof membrane system.
Polymer-coated membranes may be used to cover substantially flat roofs.
The membrane is preferably custom designed for the particular roof on which it is to be used.
The roof measurements may be provided to a factory which may create a unitary membrane from separate pieces which have been heat welded together.
Items such as vents, ductwork, air conditioning units, and the like commonly protrude from the surface of a roof.
The size and location of these items is preferably provided to the factory which creates the membrane.
With this information, the factory may make provisions for these items in the membrane.
Providing a water-tight seal around a protrusion in a roof presents a number of problems.
U.
S.
Pat.
No.
4,799,086 and U.
S.
Pat.
No.
4,872,296 disclose a method and a fitment which have been used to cover the corners of protrusions.
The fitment of these patents comprises a first generally rectangular member segment, a side being part-way split interjacent its ends, and a second member segment with a triangularly-shaped comer portion conformed to loop shape and having its marginal edges overlying portions of the first segment contiguous to the split and being welded thereto in a continuous weld seam.
This method and fitment work best when the angle of the corner is a right angle and the angle between the roof and the protrusion is a right angle.
In many cases, however, the corner is not a right angle, the protrusion is not at a right angle to the roof, or there is some other irregularity in the protrusion, such as the bottom and the top being different sizes.
In these situations, known fitments and methods do not provide satisfactory results.
The membrane must be folded or "bunched" in order to conform the membrane to the underlying structure.
The folding and bunching is unsightly, and water may collect in the folds which may have deleterious effects on the roofing membrane and/or may lead to localized leaks at seams and at other places in the membrane