Vinyl Siding Trims to Cover Roof Flashing

Flashing

• Flashing material is usually made of metal, but under-surface flashing can be constructed from self-adhesive membrane coated in bitumen, a tar-like substance frequently used on asphalt roofs. The self-adhesive membrane is usually covered over with shingles, tile or other roofing material. Extra membrane is placed along roof areas that are at risk for water leaks and damage. These areas include roof edges, seams and areas surrounding skylights, vents and chimneys. These high-risk areas are also lined with metallic flashing that is placed on top of self-adhesive membranes. Flashing acts as a waterproof bridge between different building materials like shingles or brick or vinyl siding.

Vinyl Siding

• Vinyl siding covers the sides of homes. Trim is used to line both the horizontal and vertical edges of house as well as window ledges and doors. Roofs are not covered in vinyl siding, instead shingles or other roofing materials are used. These materials lay flush with the roof's surface and allow water to run down the length of the roof slope. Trim at a roof edge will disturb optimum water flow and prevent adequate drainage.

Water Damage

• Moisture forms beads along roof edges. When the bead reaches a maximum weight, it drips. The longer the bead stays at the edge of a roof shingle, the more likely it will run back up the underside of the overhang. This trapped water causes rot, warping and other damage. Metallic flashing is a smooth surface that, when set flush against shingles along the roof edge, allows beads of water to run unimpeded from a roof to the ground. In this way, metal flashing is used to protect roof valleys from leaks and moisture. Vinyl trim, if applied over flashing, creates yet another surface capable of holding beads of water and will cause drainage problems.

Considerations

• Roof flashing is available in a range of metals. Lead and aluminum are used most often because of their low expense and malleability. Copper is an effective flashing material and is considered more aesthetically appealing than gray metals.