Loading...
HomeMy WebLinkAboutFile Documents.550 S Spring St.0053.2018 (2).ACBK .5 ;II aspen 234 e hopkins ave,aspen co 81611 + t 970 544 9006 denver 1830 blake st,ste 200,denver co 80202 + t 303 308 1373 visit www.rowlandbroughton.com rowland+broughton architecture/urban design/interior design LETTER 15 August 2018 0 L� Ll RE: W Aspen—Structural Fireproofing 0 9/12/2 018 City of Aspen Building Department, FORCOMCWIFIJANCE denism Regarding the fireproofing of building structural elements on the W Aspen, we have some specific areas aN ui i the roof top that we would like an interpretation on. We would like to propose not spray fireproofing some of the "roof" attic steel decking underside areas as they are not technically structurally supporting "roof" areas as it pertains to IBC code sections that we will illustrate have other means per fire-rated structural support and meeting code. They are spanning on top of the 12"thick concrete roof deck and part of the fully grouted CMU planter wall system. Chapter 6: - Building is Type IIA, thus 1 hr structure, 1 hr floor& roofing, etc. See table 601. - the building elements are non-combustible materials. Roof construction and associated secondary members are to be 1 hr rated. These elements are not secondary members by definition 202. (12" concrete roof deck 2hr+) Chapter 15: Roof Structures - Class B roof assembly required, we have metal roofing, Class A. - Sloped roof areas have supportive metal decking, w/5/8" glass-mat type X decking layer, then R-35ci nail base rigid insulation, high temp underlayment and SS metal roofing. - Metal decking spans from concrete slab roof structure to CMU planter wall. Arguably these could be considered part of the roof top planters and roof assembly. - 1510 Rooftop structures, possible these are covered under penthouses. Supported by CMU and concrete rooftop under, covered w/type X glass mat decking, all non-combustible and components have fire resistive ratings. See attached documents: Up on the upper deck areas, we have some triangular attic/roof/planter/weather enclosure areas as shown in the attached plans and sections. -These are isolated above the 12" concrete structural deck/roof, which is already 2+ hr min. -Technically we think these are non-structurally supporting anything life safety related. Call them aesthetic weather enclosures to continue the line of the shed roof form of the building and connected to rooftop planters. -The portions of roof that are below the structural concrete slab/outside the structural roof deck and are supporting the sloped roof above the units below as shown at the outside edge will remain 1 hr spray- fireproofed. -Thus, we would like to propose not spray fireproofing some of the"roof" attic steel decking underside areas Please see attached Architectural and Structural drawings showing the upper roof areas and technical details. Regards, pF CO Rowland + Broughton Architecture, c, p JOHN G. E. Scott McHale, Senior Project Manager "w John Rowland, Principle 4 1269 U Page 1 of 1 ��Sp ARC �\�