Gypsum Underlayment Repair Protocol Solutions

USG Durock™ Brand Tuf-Skim™ Floor Patch and USG Durock™ Quik-Top™ and Multi-Use Self-Leveling Underlayments are listed by UL Type Designation in 135 UL fire rated assemblies including the most common assemblies L521, L528, L569, L570 and L589. Multifamily floor/ceiling fire ratings can be found in the L500 and M500 series of the UL Fire Resistance Directory. Only USG Durock™ gypsum repair products are listed in an L500 or M500 assembly with insulation in the cavity. (Insulation is required to meet the building code for STC and IIC sound transmission.)

For more information on gypsum underlayment repair and code compliant fire rated UL Design assemblies, see the UL Online Certifications Directory, view the literature below or contact USG.

UL DESIGNATION TYPE LRK

L501, L502, L503, L504, L505, L506, L507, L508, L509, L510, L511, L512, L513, L514, L515, L516, L517, L518, L519, L520, L521, L522, L523, L524, L525, L526, L527, L528, L529, L530, L532, L533, L534, L535, L536, L537, L538, L539, L540, L541, L542, L543, L545, L546, L547, L549, L550, L551, L552, L556, L557, L558, L559, L562, L563, L564, L565, L568, L569, L570, L571, L573, L574, L577, L579, L581, L583, L585, L587, L588, L589, L590, L592, L593, M500, M501, M502, M503, M504, M505, M506, M508, M510, M511, M513, M515, M517*, M521*, M522*.

UL DESIGNATION TYPE HSLRK

G524, G230, G516, G535, G551*, G553*, G556, G561, G562, G564*, G566, G587, G588, G591, J917, J919, J920, J924, J927, J931, J957, J958, J991, J994, L006, L201, L206, L208, L209, L210, L211, L212, L501, L502, L503, L504, L505, L506, L507, L508, L509, L510, L511, L512, L513, L514, L515, L516, L517, L518, L519, L520, L521, L522, L523, L524, L525, L526, L527, L528, L529, L530, L532, L533, L534, L535, L536, L537, L538, L539, L540, L541, L542, L543, L545, L546, L547, L549, L550, L551, L552, L556, L557, L558, L559, L562, L563, L564, L565, L568, L569, L570, L571, L573, L574, L577, L579, L581, L583, L585, L587, L588, L589, L590, L592, L593, M500, M501, M502, M503, M504, M505, M506, M508, M510, M511, M513, M515, M517*, M521*, M522*.

UL DESIGNATION TYPE CSD

G230, G516, G524, G535, G551*, G553*, G556, G559, G561, G562, G564*, G565, G566, G587, G588, G591, G592, H502, J917, J919, J920, J924, J927, J931, J957, J958, J991, J994, L006, L201, L206, L208, L209, L210, L211, L212, L501, L502, L503, L504, L505, L506, L507, L508, L509, L510, L511, L512, L513, L514, L515, L516, L517, L518, L519, L520, L521, L522, L523, L524, L525, L526, L527, L528, L529, L530, L533, L534, L535, L536, L537, L538, L539, L540, L541, L542, L543, L545, L546, L547, L549, L550, L551, L552, L556, L557, L558, L559, L560, L562, L563, L564, L565, L568, L569, L570, L573, L574, L577, L579, L581, L583, L585, L587, L588, L589, L590, L592, L593, M500, M501, M502, M503, M504, M505, M506, M508, M510, M511, M513, M515, M521*, M525, M527, M530, M531, M532, M535, M536, M538, M541.

For the most up-to-date UL Designation Type LRK, HSLRK and CSD, contact your USG representative.

Note: *UL Design requires greater minimum pour depths and compressive strengths and/or additional requirements. See individual UL Designs for specifics.

Type CSD is UL/ULC Classified as a non-combustible material in accordance with ASTM E136 and CAN/ULC-S114.