Dating a building

Question 1

Important dates and facts

Answer 1

• Pre-1940’s was mostly wood or unreinforced masonry
• Post-1940’s saw the introduction of reinforced masonry
• ~1950 saw cinderblock construction becoming popular
• Trusses are not new! However, the gusset plates changed the framework and methods of attachment
• 1980 saw the rise of Orientated Strand Board (OSB) and Truss Joist I-beam (TJI)
o About 5 min of flame will cause failure conditions

Question 2

Commercial trusses

Answer 2

o Wide span and wide spacing
o Decreased interior partition
o High ceilings
o Exposed structural members

Question 3

Residential trusses

Answer 3

o Wide spans
o Trusses 24in on center
o Increased interior partitions
o Complex roof structures

Question 4

Container fires

Answer 4

o Conditions inside the box

o Smoke, heat, hazards

Question 5

Structure fires

Answer 5

o	Conventional framing
	Simple roof construction
	Dimensional lumber sheeting
	Ridge beams
	Simple duct work
o	Truss construction
	Fire conditions (10min rule)
	Complex roof structures
	OSB
	Tile roofs
	Flex ducts

Question 6

30’s conventional framing

Answer 6

o	Generally stronger
o	Collar ties
o	King/queen posts
o	Bearing wall
o	Ridge beams
o	Generally 2x4 long span

Question 7

30’s arch lintel

Answer 7

o Indication of un-reinforced masonry
o Line mortar
o Single hung windows

Question 8

30’s skip sheeting

Answer 8

o Skip with wood shingles or tile
o Numerous layers of roofing
o Skip filled in or covered with plywood additional dead load

Question 9

30’s high pitched roof

Answer 9

o Large attic spaces
o 8 — 12 foot not uncommon
o Attic spaces converted to living areas
o Hidden stairways

Question 10

30’s raised floors

Answer 10

o Falling through wood

o Floors become a concern

Question 11

30’s root cellers and half basements

Answer 11

o Falling through wood floors

o Especially a concern if sealed up and forgotten

Question 12

30’s cloth wiring on insulators

Answer 12

o Utilities now a concern

Question 13

30’s wood lath and plaster

Answer 13

expanded wire/ wire lath tin ceilings the ’50s’ style building
o Extreme manpower needed to open up concealed spaces

Question 14

30’s high ceilings

Answer 14

o 6ft pike pole may not reach

Question 15

30’s dormer vents

Answer 15

o Along with skip sheeting, converting an attic fire may be difficult

Question 16

30’s age of building

Answer 16

o 80-100 year old buildings can be extremely dilapidated.

Question 17

30’s balloon framing

Answer 17

o Not really seen in Tucson, but could be a possibility in older 2 story buildings
o Possibility of pancaking

Question 18

30’s box beam/columns

Answer 18

o Lightweights supporting members

o Concealed spaces

Question 19

50’s block construction/red brick construction

Answer 19

o Stronger walls
o Lime mortar usually no longer an issue
o Steel lintels
o No grout cells

Question 20

50’s steel case windows

Answer 20

o Escape may be difficult

Question 21

50’s conventional framing

Answer 21

o	Generally 2x6 construction
o	Collar ties
o	Ridge beams and poles
o	Bearing walls
o	1x6, 1 x10, sheathing

Question 22

50’s plasterboard

Answer 22

o Difficult access to ceiling and concealed spaces
o Introduction of foam to attics had the potential of dropping areas of ceiling because of absorption by 3/8” plaster board

Question 23

50’s wiring

Answer 23

o Can be brittle insulation generally not grounded
o Can become and entanglement hazard in attics
o On a short circuit can conduct electricity and transmit heat - overhaul issue

Question 24

60’s frame or block walls

Answer 24

o Pre 1978

o No grout cells

Question 25

60’s lightweight construction

Answer 25

o Prefabricated trusses
o Gusset plates
o 2x4 construction
o No ridge beams

Question 26

60’s plywood

Answer 26

o Replaces 1x6, 1x10 sheeting

Question 27

60’s half inch drywall

Answer 27

o Easy breaching

Question 28

60’s numerous additions

Answer 28

o Concealing spaces

o Questionable construction

Question 29

60’s Aluminum case windows

Answer 29

o Easy breaching

o Self-ventilating

Question 30

Present lightweight construction

Answer 30

o Elapsed time becoming critical

Question 31

Present OSB/TJI

Answer 31

o Engineering products replacing solid wood

Question 32

Present architectural diversity

Answer 32

o Concealed spaces, build-overs increasing

Question 33

Present flex duct

Answer 33

o Extreme entanglement hazard

Question 34

Present up dux

Answer 34

o Retrofit- attic involvement almost immediate

Question 35

Present engineered wood

Answer 35

o 2x4 can be the biggest piece of solid wood in the construction site

Question 36

Present alternative building materials

Answer 36

o Unconventional wall/roof/floor systems

Question 37

Present lightweight truss headers

Answer 37

o Lightweight trusses are replacing previously solid lumber