04 ATTACHMENT 1 - Laserfiche WebLink

Pleasanton Century. House Existing Structure This existing two-story house consist of steep gable style roofs framed with rough sawn 2x4 (2"x4.25") joists at 24" O.C.- The 2x4 joist are tied with 1x6 collar ties. and 1x6 web members to .create a truss effect. The roof sheathing consists of %" roof plywood over lx6 decking spanning across the 2x4's (see Photos 1 &. 2). The 111 floor framing consists of wood flooring over lx4 wood sub -flooring supported by 3x6 joists @ 24" o.c., which are support by 6x8 beams spanning between 6x6 post on concrete piers at the interior. At the perimeter of the main structure there is a 1 foot tall 3x6 @ 24" o.c. cripple wall support on an 8" CMU stem wall with an approx. 24" wide x 8" deep concrete footing (see Photo 3). In addition, the two interior corridor walls (on each side of the stairs) are support by 3x6 @ 24" o.c. cripple wall with a 1 foot tall brick foundation wall (see Photos 4 & 5). The 2nd floor framing consist of wood flooring over 1x4 sub -flooring supported by joists at 16" o.c. that span between the north and south exterior walls and the two interior corridor walls. The lateral framing system for the building consist of the existing 2x stud walls with 1x6 wood siding that act as shearwalls. The exterior of the building has a wrap-around porch that is framed with 2x6 roof joists at 24" o.c. These joists are supported by 6x6 wood beams, which are supported by 4x6 posts. The porch floor deck consists of 1x4 decking over 2x6 floor joists @ 12" o.c. over 3x6 @ 48" o.c. The 3x6 beams are supported by the building's exterior cripple wall foundation and 4x8 beams at the outside perimeter of the porch (see Photos 6,7, & 8). Design Criteria and Assumptions The Design Criteria that we use to design evaluate the existing lateral load resisting system is for this remodeling the building for continued use is as follows: • Structural Design Code: California Building Code (CBC) 2016. • Seismic and Wind design will be checked against 2016 CBC and ASCE 7-10 with Use Occupancy Category II (IE = 1.0) • Seismic Design Category is D • Roof Live Load = 20 psf (Reducible) • Floor Live Load = 40 psf Findings Orie2 Engineering performed a site visit to review the existing condition of the structure on October 12, 2018. Based on our site observations and our, structural analysis of the existing lateral system of the building, we have determined the following: 11t Floor Level: 1. The small covered wood deck at the southwest corner, shows signs of deterioration and the existing framing has shims that make it unstable (see Photo 9).: 2. The three wood stairs at the exterior (3 -sided) porch show many signs of deterioration, such as dry rot or termite damage (see Photo 10). 3. At the main building exterior foundation walls there is a 1 -foot tall wood cripple wall that is not braced. In addition, there is no means for lateral shear to transfer, through the cripple wall down to the masonry foundation.wall (see photo 3). .4. At the. two central main walls (on _each side of the stairs), the foundation consists of an unbraced and non - anchored cripple wall sitting on top of an unreinforced brick continuous: wall/footing (see photo 4). 5. At the small rear addition (west side), the. existing foundation wall consists of an unbraced cripple wall that