UL Design Number FIRM-FILL® Underlayment Thickness Number of Hours Subfloor Joists Resilient or Furring Channels Gypsum Board Batts & Blankets G230 1" 2 Midcon Metal Edge, T&G plank Steel joist, 48" OC G516 1" 2 Midcon Metal Edge, T&G plank Steel joist, 48" OC x 5/8" G524 1" 1-2 Hambro Structural Systems Composite steel joists, min nom depth 6", 49-1/4" oc, max depth 10" x 1/2" or 5/8" G553 1" 1-2 Steel Deck-Min 9/16" deep, 22MSG galv corrugated fluted steel deck Channel-shaped, 9-1/4"min depth, Min No. 16 MSG galv steel. Max 24" oc x 5/8" G561 1" 1-3 Galv. Fluted steel floor units Composite or noncomposite steel joist, spaced 48" oc, Min 10" deep (2) 5/8" G565 1" 2 Steel Deck-Min 9/16" deep, 22MSG galv corrugated fluted steel deck Channel-shaped, 9-1/4"min depth, Min No. 16 MSG galv steel, 24" oc x (2) 5/8" 3-1/2" thick G566 1" 1-2 Steel Deck-Min 9/16" deep, 28MSG galv corrugated fluted steel deck Pre fab steel truss, depth min. 12", 24" oc. G568 1" 1 Steel Deck-Min 9/16" deep, 28MSG galv corrugated fluted steel deck Channel-shaped, Min. 9-1/4" depth, Min. No. 16 MSG galv steel, 24" oc G587 1" 1-1/2 Steel Deck-Min 9/16" deep, 24MSG galv corrugated fluted steel deck Total Joist, Min. 7-1/2" deep, 20 GA min. thickness, 24" oc G595 1" 1 - 2 Steel Deck-Min 9/16" deep, 22MSG galv corrugated fluted steel deck Channel-shaped, 9-1/4"min depth, Min No. 16 MSG galv steel, 24" oc J917 1/2-1" 2 Precast Concrete J919 3/4" 2-4 Precast Concrete J920 3/4" 2-3 Precast Concrete J924 1/2" - 3/4" 2-4 Precast Concrete J927 3/4" 2 Precast Concrete J931 1/2" 2-3 Precast Concrete J957 1/2" 2-4 Precast Concrete J991 1/2-1" 1-4 Precast Concrete J994 1/2-1" 2 Precast Concrete L006 1" 1 1x6" T&G or 15/32" plywood wood structural panels 2x10, 16" oc (2) 5/8" L201 1" 1 1x6" T&G or 15/32" plywood wood structural panels 2x10, 16" oc L202 1" 1 1x6" T&G or 15/32" plywood wood structural panels Nom. 9x10" wood joists, 16" oc L206 1" 1 15/32" plywood wood structural panels Nom. 9x10" wood joists, 16" oc 1/2" L208 1" 1-1/2 1x4" T&G or 5/8" plywood 3x8", 16" oc L209 1" 1 1x6" T&G or 15/32" plywood wood structural panels 2x10, 16" oc L210 1" 1 1x6" T&G or 15/32" plywood wood structural panels 2x10, 16" oc L211 1" 1 1x6" T&G or 15/32" plywood wood structural panels 2x10, 16" oc L212 1" 1 1x6" T&G or 15/32" plywood wood structural panels 2x10, 16" oc L501 3/4" 1 19/32" wood structural panels 2x10, 16" oc 5/8" L502 1" 1 1x6" T&G or 15/32" plywood wood structural panels 2x10, 16" oc 1/2" L503 1" 1 1x6" T&G or 15/32" plywood or 7/16" OSB wood structural panels 2x10, 16" oc 1/2" L504 3/4" or 1" 1 5/8" structural interior with exterior glue, C-D Grade Douglas fir plywood Stingers 12" oc of 1200-psi graded lumber measuring 1-11/16 by 5-1/4" or greater 1/2" L505 3/4" 2 19/32" wood structural panels, 15/32" wood structural panels 2x10, 16" oc (2) 5/8 L506 1" 3/4 1x6" T&G or 1/2" wood structural panel 2x10, 16" oc 1/2" L507 1" 1 2x4" blocking under side joints 2x10, 16" oc 1/2" L508 3/4" 1 Nom. 1-1/8" thick wood structural panels, min. grade "Underlayment" 4x10 or (2) 2x10 wood joists, 12"oc X 5/8" Optional L509 1" 1/2* 1x6" T&G or 1/2" wood structural panel 2x10, 16" oc 1/2" L510 3/4" 1.5* 1x6" T&G 2x10, 16" oc X (2)1/2" L511 3/4" or 1" 2 19/32" wood structural panels, 15/32" wood structural panels 2x10, 16" oc (2) 5/8 L512 3/4" 1 19/32" wood structural panels 2x10, 16" oc 1/2" or 5/8" L513 3/4" 1 3/4" wood structural panels 2x10, 16" oc 5/8" L514 3/4" 1 19/32" wood structural panels 2x10, 16" oc 1/2" or 5/8" L515 1" 1 1x6" T&G or 15/32" plywood wood structural panels 2x10, 16" oc x 5/8" Optional L516 3/4" 1 1x6" T&G or 15/32" plywood 7/16" OSB wood structural panels 2x10, 16" oc X 5/8" Optional L517 3/4" 1 1x6" T&G 2x10, 16" oc 1/2" L518 3/4" 1 19/32" wood structural panels TRUS JOIST or TJI X (2) 1/2" L519 1" 1 1x6" T&G or 15/32" plywood wood structural panels 2x10, 16" oc 1/2" L520 3/4" 3/4* 5/8" thick plywood 2x10, 16" oc X 5/8" 3" thick L521 3/4" 1 23/32" wood structural panels Parallel chord truss, 24" oc X 5/8" Optional L522 1" 1 1x6" T&G or 15/32" plywood wood structural panels 2x10, 16" oc 1/2" L523 1" 1 5/8" thick plywood 2x10, 16" oc Optional 5/8" L524 3/4" 1 19/32" wood structural panels Steel joists with 7" min. depth, 24" oc (2) 5/8" L525 1" 1 1x6" T&G or 15/32" plywood wood structural panels 2x10, 16" oc 1/2" L526 1" 1 1x6" T&G or 15/32" plywood wood structural panels 2x10, 16" oc 1/2" L527 3/4" 1.5* 3/4" thick plywood, min grade "Underlayment" Steel joists with 9-3/8" min. depth, 24" oc X (2) 5/8" L528 3/4" 1 23/32" wood structural panels Parrallel chord truss, 24" oc X 5/8" L529 3/4" 1 23/32" wood structural panels Parrallel chord truss, 24" oc 5/8" L530 3/4" 1 3/4" plywood TRUS JOIST or TJI X 1/2" or 5/8" 1-1/4" thick L533 3/4" 1 4x8" x 5/8" thick wood structural panels 2x10, 16" oc X 5/8" Optional L534 3/4" 1 23/32" plywood wood structural panels Parallel chord truss, 24" oc X 5/8" L535 3/4" 1 19/32" wood structural panels 2x10, 16" oc X 1/2" or 5/8" L536 1" 2 15/32" wood structural panels 2x10, 16" oc (2) 5/8" L537 3/4" 1 5/8" thick plywood 2x10, 16" oc 1/2" or 5/8" L538 3/4" 2 1/6" T&G or 15/32" plywood or 7/16" OSB Min. 14" deep wood and steel truss, 19.2" oc X (3) 5/8" L538 3/4" 2 1/6" T&G or 15/32" plywood or 7/16" OSB Min. 9-1/2" deep "I" shaped joist, max 19.2" oc X (3) 5/8" L539 3/4" 1 1x6" T&G or 15/32" plywood 2x10, 16" oc 5/8" Optional L540 3/4" 1 1x6" T&G or 15/32" plywood 2x8 wood joists, 16" oc 5/8" Optional L541 1-1/2" 2 15/32" plywood wood structural panels 2x10, 16" oc x 5/8" 3" thick L542 1" 1 Nom. 23/32" wood structural panels, min grade "Underlayment" Parallel chord truss, 24" oc (2) 1/2" L543 3/4" 1 Nom. 23/32" wood structural panels, min grade "Underlayment" C-shaped sections, min 8" deep, 1-9/16" flanges (2) 1/2" L545 3/4" 1 3/4" wood structural panels 2x10, 16" oc X 5/8" Optional L546 3/4" 1 15/32" wood structural panels Parallel chord truss, 24" oc with nom 2x4 lumber. Min. truss depth 18" X 5/8" Optional L547 3/4" 1.5* 5/8" thick plywood Min. 9-1/2" deep "I" shaped joist, max 19.2" oc X (2) 1/2" Optional L549 3/4" 1 23/32" wood structural panels Pre-fab light gauge steel truss max 48" oc X 5/8" Optional L550 3/4" 1 23/32" wood structural panels Parallel chord truss, 24" oc X 5/8" Optional L551 3/4" 1 23/32" wood structural panels Pre-fab light gauge steel truss max 48" oc X 5/8" Optional L552 3/4" 1 23/32" T&G plywood Pre-fab light gauge steel truss max 48" oc X 5/8" Optional L556 1" 2 23/32" wood structural panels Channel-shaped steel joist, min 8" deep, min. 18 MSG galv steel, 24" oc X (4) 5/8" L556 1" 2 23/32" wood structural panels Min. 9-1/4" deep "I" shaped wood joist, 24" oc X (4) 5/8" L556 1" 2 23/32" wood structural panels 2x8 or 2x10, 24" oc X (4) 5/8" L557 3/4" 1 15/32" wood structural panels 2x10, 16" oc 5/8" L558 3/4" 1 23/32" wood structural panels Parallel chord truss, 24" oc X 5/8" X L560 3/4" 1 23/32" wood structural panels Pre-fab light gauge steel truss max 48" oc X 5/8" Optional L562 3/4" 1 23/32" T&G wood structural panels Parallel chord truss, 24" oc with nom 2x4 lumber, truss depth 18" x 5/8" 3-1/2" L563 3/4" 1 23/32" T&G wood structural panels Parallel chord truss, 24" oc with nom 2x4 lumber, truss depth 18" X 5/8" Optional L564 3/4" 1 Viroc Structural Cement-Fiber Units Metal Joist x 5/8" x L565 3/4" 1 23/32" wood structural panels Pre-fab light gauge steel truss, 48" oc x 5/8" Optional L569 3/4" 1 15/32" plywood wood structural panels 2x10, 16" oc x 5/8" Optional L570 3/4" 1 19/32" wood structural panels Min. 9-1/2" deep "I" shaped joist, max 24" oc x (2) 1/2" or (2) 5/8" Optional L571 3/4" 1 5/8" T&G structural panels Min. 9-1/4" JSI 4000 I shaped joist, 24" oc x 5/8" 2-1/2" L573 3/4" 1 3/4" thick plywood, min grade "Underlayment" Channel-shaped, 9-3/8" min depth, Min No. 16 MSG galv steel, Max 24" oc (2) 5/8" L574 3/4" 1 23/32" T&G plywood Parallel chord truss, 24" oc x 5/8" Optional L576 3/4" 1 23/32" plywood wood structural panels Parallel chord truss, 24" oc x 5/8" 3-1/2" L577 3/4" 2 19/32" wood structural panels Parallel chord truss, 24" oc x (3) 5/8" x L579 3/4" 1 19/32" wood structural panels Parallel chord truss, 24" oc x 5/8" Optional L581 3/4" 1 3/4" plywood Min. 9-1/2" deep "I" shaped joist, max 24" oc (2) 5/8" x L581 3/4" 1 3/4" plywood 2x10, 16" oc (2) 5/8" x L583 3/4" 1 3/4" plywood Min. 9-1/2" deep "I" shaped joist, max 24" oc x (2) 5/8" x L583 3/4" 1 3/4" plywood Parallel chord truss, 24" oc x (2) 5/8" x L583 3/4" 1 3/4" plywood 2x10, 16" oc x (2) 5/8" x L585 3/4" 1 23/32" T&G wood structural panels Parallel chord truss, 24" oc with nom 2x4 lumber. Min. truss depth 18" X 5/8" Optional L587 3/4" 1 23/32" wood structural panels Parallel chord truss, 24" oc x 5/8" Optional L588 3/4" 1 15/32" wood structural panels 2x10, 16" oc 5/8" L589 3/4" 1 19/32" wood structural panels Min. 9-1/2" deep "I" shaped joist, max 19.2" oc x (2) 1/2" or (2) 5/8" x L590 3/4" 1 15/32" wood structural panels 2x10, 16" oc x 5/8" Optional L592 3/4" 1 23/32" plywood wood structural panels Parallel chord truss, 24" oc x 5/8" Optional L593 3/4" 1 15/32" wood structural panels 2x10, 16" oc 5/8" L598 3/4" 1 5/8" plywood wood structural panels 2x10, 16" oc X 5/8" 3-1/2" thick M500 3/4" 2 19/32" wood structural panels Parallel chord truss, 24" oc (3) 5/8" M502 3/4" 1 19/32" wood structural panels Min. 9-1/2" deep "I" shaped joist, max 19.2" oc x (2) 5/8" Optional M503 3/4" 1 23/32" T&G plywood Parallel chord truss, 24" oc x 5/8" x M504 3/4" .75 19/32" wood structural panels 2x10, 16" oc 5/8" M505 3/4" 1 19/32" wood structural panels Steel joist with 8" deep, min. 1-5/8" flanges, min. 9/16" stiffening flanges x (1) 5/8" with RC, (2) 5/8" without RC 3-1/2" thick M506 3/4" 1 19/32" wood structural panels Min. 9-1/2" deep "I" shaped joist, max 19.2" oc x (2) 1/2" or (2) 5/8" Optional M508 1" 1 23/32" T&G wood structural panels Parallel chord truss, 24" oc x 5/8" Optional M511 3/4" 1 3/4" plywood Steel joist with min 10" deep, 18 GA, spaced 24" oc x 5/8" 3" thick M512 7/8" 1 23/32" T&G plywood Min. 18" I-joist, spaced 24" oc x 5/8" M515 3/4" 1 3/4" T&G plywood Steel joists with 7" min. depth, 24" oc x 5/8" x M519 3/4" 1 15/32" plywood wood structural panels 2x10, 16" oc Optional 5/8" Optional