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.