Reroofing Information

Parts of a Standard Roof

• Before reroofing, homeowners or contractors must inspect all of a roof system's components. Standard roofs consist of framing, sheathing, flashing, roofing paper and a roof covering. The term framing refers to the rafters or joists, usually lumber, and the term sheathing refers to sheet goods, such as plywood, that cover framing. Reasons to replace framing and sheathing include rot, pest infestation and physical damage. Flashing consists of the metal angles or sheets that cover the roof's edges or valleys. Damaged or improperly sealed flashing requires replacement. Roofing paper, or tar paper, covers sheathing and flashing. Torn, rotten or damaged roofing paper requires replacement. As a roof's first line of defense, roof coverings, such as shingles and sheets, must be free of surface damage and create a watertight seal.

Types of Roof Coverings

• Common types of roof coverings include shingles, rolled roofing, rigid roofing panels and roof tiles. Shingles and rolled roofing on modern homes are typically composed of thick building building paper impregnated with fibers and asphalt; rigid roofing panels for residential structures are typically metal and roof tiles are available in clay, concrete or natural stone. Building codes sometimes allow lightweight roofing materials, such as shingles and rolled roofing, to be applied directly over existing roof coverings. However, installing heavy materials, particularly tiles, over a roof that previously held light materials requires additional structural support, such as thicker framing or sheathing.

When to Perform Reroofing

• Leaks are the most obvious indication of roof damage. Although small, infrequent leaks do not necessitate an entire roof replacement, consistent, seasonal leaks deserve investigation. If a roof appears worn from ground level or roof covering materials loosen during high winds, a roof might require replacement. As roof covering materials near the end of their warranty agreements, homeowners should consider reroofing.

Tear Off vs. Cover Over

• Whereas tearing off and completely reroofing requires substantial labor and expense, covering over an existing roof is relatively quick and inexpensive. However, covering over a seriously damaged roof provides only a temporary solution to roof issues and sometimes voids the warranty of reroofing materials. Additionally, most municipalities require inspection and approval prior to covering over an existing roof. Even if your local building authority doesn't require inspection, a qualified contractor or inspector can help you determine the best course of action.