HomeMy WebLinkAboutFile Documents.820 E Hyman Ave.0085-2023-BRES (7)
OCTOBER 02, 2023 VIA ELECTRONIC SUBMITTAL
ATTN. BONNIE MUHIGIRWA CBO
CITY OF ASPEN COMMUNITY DEVELOPMENT | BUILDING
427 RIO GRANDE PLACE
ASPEN, CO 81611
RE: NEW HEARTH EXTENSION TO EXISTING MANUFACTURED FIREPLACE
820 E. HYMAN STREET
ASPEN, CO 81611
REQUEST FOR APPROVAL FOR ALTERNATIVE ASSEMBLY PER 2021 IBC [A}104.11
DEAR BONNIE:
WE HAVE BEEN WORKING WITH LINZHI DOUGLASS IN YOUR DEPARTMENT TO FIND AN ACCEPTABLE
ASSEMBLY & REGULATORY PATH TO APPROVAL FOR REPLACING AN EXISTING HEARTH EXTENSION WITH
A NEW ONE FOR A 1989-90 MANUFACTURED UNIT FIREPLACE APPLIANCE (SUPERIOR MDL# 1038),
FOR WHICH WE DO NOT HAVE AND CANNOT FIND INSTALLATION DOCUMENTATION. ABSENT THIS
DOCUMENTATION, THE ONLY PATH FORWARD SEEMED TO BE FULL COMPLIANCE WITH NON-
COMBUSTIBLE SUPPORT REQUIREMENTS FOR THE EXTENSION PER 2021 IBC 2111.10 & 11 FOR
MASONRY FIREPLACES.
THE EXISTING HEARTH EXTENSION IS 16”D X 76”W BUILT OF 5/16” CERAMIC TILE ADHERED TO 1/2”
PLYWOOD ON 3/4” PLYWOOD FLOOR SHEATHING. WHILE CLEARLY NOT AN IDEAL ASSEMBLY, IT HAS
BEEN IN SERVICE FOR 34-YEARS WITHOUT INCIDENT. GIVEN THE EXISTING WOOD-FRAME
CONSTRUCTION AND LIMITED SCOPE OF THE REMODEL, WE CANNOT FEASIBLY PROVIDE NON-
COMBUSTIBLE SUPPORT FOR THE HEARTH EXTENSION AS IF THIS WERE A MASONRY FIREPLACE.
UNLESS WE CAN AGREE TO AN ALTERNATIVE ASSEMBLY THAT MEETS THE INTENT OF CURRENT CODE,
OUR OPTION IS TO LEAVE THE EXISTING SUB-STANDARD HEARTH EXTENSION IN-PLACE.
IN DISCUSSION WITH THE DENVER-BASED SUPERIOR FIREPLACES DEALER, WHILE THEY CANNOT
ACCESS A COPY OF THE 34-YEAR OLD 1989-90 INSTALLATION GUIDE, HE SAID THAT THE CURRENT
SUPERIOR MODEL# WRT2036 IS VIRTUALLY IDENTICAL TO OUR EXISTING 20”H X 36”W OPENING
(I.E. <6 SF) SUPERIOR FIREPLACE MDL# 1038, AND SUGGESTED THAT WE REFER TO THE CURRENT
INSTALLATION GUIDE FOR THE WRT2036. I ATTACH THAT DOCUMENT TO THIS PROPOSAL HEREWITH
WITH RELEVANT SECTIONS HIGHLIGHTED.
THIS INSTALLATION GUIDE REQUIRES THE FOLLOWING FOR THE HEARTH EXTENSION:
•USE OF A MINERAL FIBER NON-COMBUSTIBLE SUBSTRATE WITH A THERMAL CONDUCTIVITY K-
FACTOR = 0.84 @1”;
•MINIMUM HEARTH EXTENSION DIMENSIONS OF 16”D X 52”W;
•USE OF A CONTINUOUS MIN. 28-GAUGE GALVANIZED SHEET METAL “EMBER PROTECTOR”
EXTENDING UNDER THE FIREPLACE UNIT A MINIMUM 1 1/2”;
•APPLICATION OF A NON-COMBUSTIBLE SEALANT BETWEEN THE FIREBOX AND THE EXTENSION.
TO ACHIEVE THESE REQUIREMENTS, WE PROPOSE FOLLOWING:
•THE NEW HEARTH EXTENSION WILL HAVE A MINIMUM DEPTH OF 16” AND WIDTH OF 76” TO MATCH
THE WIDTH OF THE EXISTING SURROUND;
•REMOVE EXISTING 3/4” PLYWOOD SHEATHING BENEATH THE HEARTH EXTENSION, INSTALLING
LEDGERS AS REQUIRED;
•INSTALL A CONTINUOUS 28-GAUGE SHEET METAL Z-PROFILE EMBER PROTECTOR EXTENDING A
MINIMUM 1 1/2” UNDER THE FIREBOX & PROJECTING 1 1/2” FORWARD (SEE INSTALLATION
MANUAL PAGE 6);
•INSTALL 3/4” THICK USG MICORE 300 MINERAL FIBER INSULATION BOARD FLUSH WITH
SHEATHING (THE USG MICORE 300 INSULATION THAT WE PROPOSE HAS A K-FACTOR OF 0.48
(SEE ATTACHED SPEC SHEET), WITH A REQUIRED THICKNESS OF 0.57” (THE PROPOSED 3/4”
THICKNESS EXCEEDS THIS REQUIREMENT);
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10/12/2023
820 E. HYMAN • REQUEST FOR APPROVAL FOR ALTERNATIVE ASSEMBLY (CONTINUED)
•OVER THE MICORE, INSTALL 1/2” DUROCK CEMENTITIOUS UNDERLAYMENT;
•OVER DUROCK, ON NON-COMBUSTIBLE THIN-SET MORTAR, INSTALL MINIMUM 2CM SLAB STONE OR
QUARTZ HEARTH EXTENSION FINISH MATERIAL;
•SEAL THE GAP BETWEEN THE HEARTH EXTENSION & FIREBOX WITH NON-COMBUSTIBLE SEALANT.
WE MAINTAIN THAT THE ABOVE-DESCRIBED INSTALLATION IS CONSISTENT WITH THE
MANUFACTURER’S REQUIREMENTS AND RECOMMENDATIONS PER THE DOCUMENTS ATTACHED BELOW.
FURTHERMORE, WE BELIEVE IT IS CONSISTENT WITH THE INTENT OF 2021 IBC, AND GREATLY
IMPROVES PERFORMANCE AND FIRE-RESISTANCE COMPARED WITH THE EXISTING ASSEMBLY
PLEASE CONTACT ME DIRECTLY WITH ANY QUESTIONS OR COMMENTS. YOU CAN ALWAYS REACH MY
CELL 970 948 4269 OR EMAIL ROB@SIN-BAD.COM
SINCERELY,
ROBERT G. SINCLAIR AIA
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Alternate method approved in accordance with 2021
IBC 104.11
October 6, 2023
10/12/2023