Glossary – U

UL:   Underwriters Laboratories, Inc.

Ul Label:   Label displayed on packaging to indicate the level of fire and/or wind resistance of asphalt roofing.

Undercut:   To cut away inner edges of a crack or hole in the shape of an inverted V in order to provide a stronger base for patching material.

Underfloor Crawl Space: The area within the confines of the foundation and between the ground and the underside of the lowest floor structural component.

Underfloor Wiring System:   A system in which ducts or raceways are built into a floor to house electrical wiring.

Underlayment:   Asphalt saturated felt used beneath roofing to provide additional protection from the deck.

Underpinning:   Timbers, steel beams or other temporary props used to support a foundation during construction; also permanent supports installed to increase the load-bearing capacity of a foundation or wall.

Utility Room:   A room that is designed or used for laundry, heating, equipment or related purposes.