Installation Guide

Floor Construction
ENGINEERED WOOD CONSTRUCTION GUIDE
■
FORM NO. E30V
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© 2011 APA – THE ENGINEERED WOOD ASSOCIATION
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WWW.APAWOOD.ORG
42
TABLE 15 continued
TCNA
No.
Service
Classification
(a)(b)
Max. Joist
Spacing
(in. o.c.)
Tile
Adhesive
Underlayment
Layer
Subfloor
Layer Comment
F155 Residential
(d)
24
Latex-portland
cement mortar
19/32" Exposure 1
plywood
23/32" Exposure 1
T&G OSB or
plywood
OSB subfloor OK
F160
Light
Commercial
24
Latex-portland
cement mortar
3/8" plywood
23/32" Exposure 1
T&G plywood
8" x 8" or larger
tile only
F170
Residential
or Light
Commercial
16
Latex-portland
cement mortar
Fiber-reinforced
gypsum panel
19/32" Exposure 1
plywood
—
F175
Residential
or Light
Commercial
16
Dry-set mortar
or latex-portland
cement mortar
Cementitious-
coated foam
backerboard
19/32" Exposure 1
plywood
8" x 8" or larger
tile only
F180
Residential
or Light
Commercial
16
Poured gypsum
minimum 3/4"
23/32" Exposure 1
T&G plywood
Uncoupling
Membrane
F185 Residential 19.2
Latex-portland
cement mortar
Cementitious
self-leveling
23/32" Exposure 1
T&G plywood
—
RH122 Residential 16 — Mortar bed
23/32" Exposure 1
T&G plywood
Crack isolation,
waterproof, or
uncoupling
membrane
RH123 Residential 16 — Mortar bed
23/32" Exposure 1
T&G plywood
Crack isolation
waterproof, or
uncoupling
membrane
RH130
Residential
or Light
Commercial
16
Latex-portland
cement mortar
Light Commercial-
19/32" Exposure 1
plywood
19/32" Exposure 1
T&G plywood
Use of 15/32"
plywood
underlayment
layer gives
“Residential”
performance
RH135
Residential
or Light
Commercial
16
Dry-set mortar
or latex-portland
cement mortar
Cementitious
backer unit
23/32" Exposure 1
T&G plywood
Use of 19/32"
plywood
subfloor gives
“Residential”
performance
RH140 Residential 19.2
Latex-portland
cement mortar
Cementitious
self-leveling
23/32" Exposure 1
T&G plywood
—
RH141
Light
Commercial
16
Latex-portland
cement mortar
Cementitious
self-leveling
19/32" Exposure 1
T&G plywood
Use of glass tile
may lower service
classification
(a) Order of increasing serviceability: Residential, Light
Commercial, Moderate and Heavy
(b) As typically performed, the ASTM C 627 Robinson-Type Floor
Tester delivers three, simultaneous dynamic, 300-pound
concentrated wheel loads moving in a 30-inch-diameter circle
over the surface of test assembly. The number of cycles the
system withstands without failure determines its Service
Classification. One criterion used to determine failure is a maxi-
mum deflection of L/360 under the three concentrated loads.
(c) 1-1/2 inch net support width permitted with 8x8 inches or larger
tile—otherwise 2-1/4 inches net support width is required.
(d) Passed ASTM C 627 tests with a “Light Commercial” rating using
plywood as the subfloor and then again with OSB as the subfloor.