R-value: The thermal resistance of insulation or a glazing system. The R-value is the reciprocal of the U-value. The higher the R-value, the less heat is transmitted throughout the insulation or glazing material.

raceway: an enclosed channel or conduit designed expressly for holding wires or cables.

radiant heat transfer: Radiant heat transfer occurs when there is a large difference between the temperatures of two surfaces that are exposed to each other, but are not touching.

rafter: A sloping roof member that supports the roof covering and extends from the ridge or the hip of the roof to the eaves.

rail: the side members of a fixed ladder joined by cleats, rungs, or steps at uniform intervals.

rail ladder: a type of fixed ladder that consists of two long sides (rails) crossed by parallel rungs, cleats, or steps.

ramp: a sloped walking surface.

re-entrainment: Situation that occurs when the air being exhausted from a building is immediately brought back into the system through the air intake and other openings in the building envelope.

readily accessible: describes the area of the subject property that has been made available to the inspector at the time of the walk-through survey portion of the inspection, and/or a system or component that, in the judgment of the inspector, is capable of being safely observed without the need of portable ladders, the removal of obstacles, the detachment or disengagement of connecting or securing devices, or other unsafe or difficult procedures to gain access, and/or a document that has been made available to the inspector for use in the research portion of the inspection.

readily achievable: an action that can be carried out without undue monetary expense or complication.

readily available: describes the information, personnel and documents that are made available quickly to the inspector.

rebar: Nickname for reinforcing bar; used to increase the tensile strength of concrete.

receptacle: a contact device installed at the outlet for the connection of an attachment plug.

recreational facilities: spas, saunas, steam baths, swimming pools, tennis courts, playground equipment, and other exercise, entertainment or athletic facilities.

reinforced concrete (RC): A composite of two materials: concrete and reinforcing steel (bars and mesh) using the best of both properties.

reinforcing bar (rebar): Steel rods or metal fabric placed in concrete slabs, beams or columns to increase their strength; also referred to as tendons.

RELs: Recommended Exposure Limits (recommendations made by NIOSH).

remaining useful life: a subjective estimate or guess made by the inspector based upon his observations and experience as to the number of remaining years that a component will be functional before needing replacement.

removable: capable of being transferred to another location easily.

repair: the reconstruction or renewal of any part of an existing building.

replacement air: air deliberately brought into a structure to compensate for the air being consumed or expelled.

report: the written communication describing the issues discovered from observations made and research conducted by the inspector and which, in the inspector’s opinion, are likely to be of interest to his/her client.  A report may contain photos or digital images of observations made during the walk-through survey portion of the inspection, and/or copies of documents reviewed during the research portion of the inspection.

representative number: a sufficient number to serve as a typical or characteristic example of the item(s) inspected.

representative sampling: a small quantity of components of any system or structure, enough like others in its class or kind, to serve as an example of its class or kind.

research: the process of gathering information through the review of documents and interviews to augment the observations made during the walk-through survey portion of the inspection.  This research may include reviewing readily available documents, such as previous inspection reports, building permits, code violation notices, and environmental studies.  This research may also include interviews with readily available personnel, such as building managers, tenants and owners.

retaining wall: A structure that holds back a slope and prevents soil erosion.

RICS: Royal Institute of Chartered Surveyors (U.K.)

ridging: Also commonly known as buckling, a term used to describe upward linear tenting of a low-slope roof membrane, usually found over insulation and deck joints.

rolled/roll roofing: A general term used to describe low-slope roof materials that are packaged into rolls, typically consisting of smooth- or mineral-surfaced felts.

roof assembly: a system designed to provide weather protection and including the roof covering, underlayment, roof deck, insulation, vapor retarder and interior finish.

roof deck: Structural component of the roof that serves as the substrate for the installation of the roof system.

roof joist: One of a series of parallel framing members used to support ceiling loads, and supported, in turn, by larger beams, girders or bearing walls.

roofing system: Consists of the components installed on top of a roof deck (but not the deck itself) that together protect the building’s interior from weather, including providing resistance to moisture intrusion, and often acts as part of the thermal/pressure envelope. In a membrane roof, this is an air or vapor retarder, insulation, and the membrane designed as the primary weather barrier.

rubbish: waste materials other than garbage.

RUL: remaining useful life

rung: a crosspiece forming the step at the circular or oval cross-section of a fixed ladder.