2101 LEXINGTON AVE 2021-09-24 - Laserfiche WebLink

i Yen Design Inc.—2101 LexiigtanAve Plan Review Comments 7-28-2020 ■ Comment 4. The lateral load path for the roof structure is not dear The east side appears intended to act as a cantilever column system for the north south loading. However,the west side and the east-west direction appear to rely on the existing structure for lateral support. The structure should be designed for lateral support per Section 12.8and 12 Z3. Calculations substantiating the load path should be submitted for review The existing structure should be evaluated per/EBC Section 1103,3.See IBC Sections 1014.7and 1613.1 Response: As stated in comment 3,each exterior post adjacent to the existing structure has a minimum of 9 screws fastened back to the existing structure,which has a total withdraw capacity of about 3.6 kips.The maximum lateral load that the covered porch experiences is 1.4 kips in either direction(north-south or east-west).Idealizing the corrugated panels as a rigid roof diaphragm,half of the lateral load,or 0.7 kips,will be resisted by the west side of the diaphragm in the north-south direction. Because there are 3 posts on the west side of the covered roof fastened back to the existing structure,the existing structure is required to resist 0.23 kips of load at each location where the exterior posts are fastened.Therefore,the 9 screws are adequate in transferring lateral load into the existing structure in each direction.It is our professional opinion that,by inspection,the existing structure is able to resist any additional lateral load imposed on it by the new covered patio given such low values. • Comment 5:The 2x10 rafters bear on the 4x8 beams along the east edge of the proposed structure.Connection do not appear to be provided. Connections should be specified providing adequate strength for both lateral load transfer and resistance to uplift. Calculations substantiating the connection design should be submitted for review. Response: Please see the revised notes for typical connection between the roof rafters and covered porch beams.Typical connections,which consist of(2)SDWC1500 toescrews,are adequate for both lateral and uplift forces.The withdrawal capacity of the typical connection is approximately 270 lbs,and the shear capacity of the typical connection is approximately 340 lbs. • Comment 6:The roof framing does not appear to be provided with adequate weather protection to prevent exposure and deterioration,notably around the perimeter. The project should speciy Bashing around the per/meter,or alternativey the use of preservative-treated or naturally-durable wood Cut ends of wood members should be coated with a preservative treatment comply with AINPAM4. See IRC Sections R3171.1 and R903 Response: Roof framing has been revised to show pressure treated wood.Please see updated structural plans and beam calculations. Please feel free to call if you have any questions. t3�S OV w�r3 Respectfully, AtY C col MULHERN & KULP STRUCTURAL ENGINEERING, INC. ' f- ! `- y� Warren Chan Project Engineer q ' 1547$ 4 A Nicholas 1 Martignetti,P.E. Project Manager 9.0 40rsrP $ 410NAL e Seal&i, 2