- roofed bridge
- roofer
- roofing clip
- roofing iron
- roofing nail
- roofing pitch
- room
- room area
- room capacity
- room heater
- root barrier
- root dozer
- rootball
- rope block
- rope drill
- rope grab
- rope hoist
- rope pull
- ropeway car
- rosarium
- rose wood
- rostral column
- rot
- rot protection
- rotary bit
- rotary boring
- rotary brush
- rotary compressor
- rotary crane
- rotary cutter
- rotary ditcher
- rotary drill
- rotary drilling
- rotary printing
- rotary ratchet
- rotary rig
- rotary screen
- rotary stage
- rotary switch
- rotating beacon
- rotating crane
- rotating deck
- rotating shovel
- rotation handle
- rotor
- rough board
- rough boring
- rough calculation
- rough check
- rough coat
- rough cut
- rough floor
- rough painting
- rough string
- rough terrain
- rough timber
- rough work
- rough-hewn
- rougheast
- roughness
- round aggregate
- round bar
- round shake
- rounded material
- rounded-off
- rounds
- route development
- route locking
- route sheet
- route transport
- routine repair
- row spacing
- royal city
- rubber belt
- rubber membrane
- rubber sheet
- rubble ashlar
- rubble fill
- rubble paving
- rubble stone
- rugosity
- rules
- runoff
- runoff variability
- runway shoulders
- rupture test
- rupturing cap
- rural district
- rural locality
- rural school
- rush hours
- rust mark
- rustic brick
- rusticated column
- rusting
- S-trap
- saddle bend
- saddle frame
- saddle roof
- saddle tractor