1804 HEWITT AVE 2022-05-12 - Laserfiche WebLink

• • NEW HEWITT/HODGES ASSOCIATES,LLC Page 3 HODGES BUILDING—ELEVATOR HOISTWAY ALTERATION January 12, 17 Review of Fire-Resistive Construction Provisions CONSIDERATION In accordance with IBC provisions,this existing construction should be considered to provide the required 1-hour FRR construction.This conclusion is appropriate as the existing construction of the elevator hoistway wall is consistent with IBC Section 602.4.6 for heavy- timber construction (HTC). Table 601 of the IBC allows use of either 1-hour FRR construction or HTC interchangeably; as presented in Footnote c to the table and with regard to interior bearing walls in Type IV construction. In order to maintain the level of fire protection previously established for the combustible framing, consistent with IFC Section 1103.1,the interior surface of the elevator hoistway walls should be patched to restore locations where the plaster finish previously existed. CONCLUSION The construction of the existing elevator hoistway is consistent with IBC provisions for 1- hour FRR construction. Therefore,where the existing hoistway construction remains, it should continue to be acceptable in accordance with IFC Section 1103.4.3. However, missing areas of plaster finish should be patched. Alternatively, the installation of gypsum wallboard (gwb) having a minimum thickness at least equivalent to that of the existing plaster would afford an enhanced level of protection. Fastening the gwb to the framing should improve the integrity of the finish as it would be less susceptible to fracture and delamination. In addition, as plaster appeared to exist to a much greater extent than not,the resulting thickness of finish material with the addition of gwb would be increased. This increased thickness would improve the fire resistive integrity of the wall. NEW HOISTWAY CONSTRUCTION While the hoistway itself is existing, enlarging it involves construction of new walls and structural supports for which IBC provisions should be applicable. Section 3404.1 of the IBC addresses alterations. While this provision could be strictly interpreted to require the new walls to be of 2-hour FRR construction, this provision also prescribes, "Alterations shall be such that the existing building or structure is no less complying with the provisions of this code than the existing building or structure was prior to the alteration." OBSERVATIONS If the replacement elevator was installed within the existing hoistway,the existing 1-hour construction would continue to be acceptable (even in the absence of sprinkler protection). However, to satisfy modern provisions to accommodate an ambulance stretcher,the existing hoistway is being enlarged. An existing beam at each floor extends to a column at the face of the existing hoistway.This column must be removed and the beam shortened as AEGIS Engineering, PLLC