Report (25) .111
RECEIVED 1100 NE 28th Ave#212
Portland,OR 97232
JUN 13 2016 (503)706-7380
ed@edcrabaugh.com
CITY OF TIGARD E C E
BUILDING DIVISION
EDWARD CRABAUGH
ENGINEERING CONSULTING,P.C.
Date: June 13, 2016
City of Tigard
Community Development Department
13125 SW Hall Blvd
Tigard, OR 97223
RE: Main Street Village Apartments, 9270-9492 SW Maplewood
Permit nos. BUP2016-00094 thru BUP2016-00118
Dear City of Tigard,
This letter addresses exterior wall sheathing replacement associated with the re-siding project referenced
by addresses and permit numbers above. Based on limited siding removal at the time of this letter,the
vast majority of exterior wall area appears to be sheathed with '/Z"gypsum wallboard fastened with
drywall nails approx 7"o.c. Other, isolated areas, most likely involved in past repairs, are sheathed with
'/z"OSB.
ECEC proposes that the existing sheathing be replaced in its entirety with new 1/2"plywood,fastened to
wall framing with 8d nails at 6"o.c. (12"o.c.field nailing)per current industry standard practice. This will
represent a substantial improvement in wall shear strength over existing conditions. Per the American
Wood Council National Design Standards—Special Design Provisions for Wind and Seismic, the
Allowable Stress Design (ASD)shear value of walls constructed in this manner is 260 plf seismic and 365
plf wind. Please see the table 4.3A on the following page. This will represent a 4X seismic/5X wind
increase over current wall shear strength.
In many places,the apartment units are offset from each other in plan, creating the need for 1-hr fire
resistance at exterior walls. In these locations, ECEC proposes 5/8"Densglass Fireguard sheathing in
lieu of h/2"plywood, to comply with fire code. These areas of wall are extensions of the party walls which
are long,feature no openings, and therefore typically provide ample shear resistance. The Densglass
panels should be installed using 1-1/4" Bugle head, rust resistant, coarse thread, sharp point screws at 8"
o.c. along panel edges and all framing members per manufacturer's specifications.
Sincerely,
��9V) PROp,
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Edward W. Crabaugh, P.E. �"�` ,`` `''
City of Tigard %'T 0 wrcRPgti�
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REVISION
OFFICE COPY
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Table 4.3A Nominal Unit Shear Capacities for Wood-Frame Shear Waiis''3,67
13 Wood-based Panels4
I� �� Am B
Minimun SEISMIC vv WIND
rn Minimum Fastener Panel Edge Fastener
Fastener Panel Edge Fastener Spacing(In.}
Sheathing NominalPn
anlIn Framing
�_ Spacing(in.)
la Material Panel Framing Type 8 Size 4 3 2 6 4 3 2
a Thickness Member or "—'
(in.) Blocking v".� �•. v. G. v. G, v. G. vw v,Y vw
n (in.) (pit) (kips/In.) (pif) (kips/in.) (pif) (kipslin.) (pit) (kips/in.) (pit) (pit) (ptf) (pit)
5 ( Nall(common or Osa PLY OSB PLY 096 PLY 096 PLY
galvanized box)
Wood 5116 1-114 6d 400 13 10 600 18 13 780 23 16 1020 35 22 _560 840 1090 1430
ea Structural L. -1-
3/13 460 19 14 i 720 24 17 92C 30 20 1220 43 24 845 1010 1290 1710
Panels t
Structurall`'s 7118= 1-3/8 8d 510 16 13 790 21 16 1010 27 19 1340 40 24 715 1105 1415 1875
a
15/32 560 14 11 8130 18 14 1100 24 17 1480 37 23 785 1205 1540 2045
15/32 1-1/2 10d 580 22 18 1020 29 20 1330 36 22 1740 51 28 950 1430 1860 2435
5/16 1-1/4 Sd 360 13 9.5 ( 540 18 12 700 24 14 900 37 18 505 755 960 1260
3/8 400 11 8.5 600 15 11 78C 20 13 1020 32 17 560 840 1090 1430
Wood ructural 3/84 440 17 12 840 25 16 820 31 17 1060 45 20 615 895 1150 '; 1485
PanelsSt - 1-3/8131 480 15 11 ( 700 22 14 900 28 17 1170 42 21 980 1280 { 1640
Sheathing"5 15/32 520 13 10 760 19 13 980 25 15 1280 39 20 730 1065 1370 M1790
GYO 22 14 920 30 17 1200 37 19 1540 52 23 1293 1689 2155
19/32
1-1/2 106 680 19 13 1020 26 16 1330 33 18 1740 48 22 950 1430 1860 1 2435
Plywood Nail(galvanized casing)
a Stding 5/16 1-1/4 66 280 13 420 16 550 17 720 21 390 590 770 1010
w 3/ 8 1-318 86 320 16 480 18 620 20 820 22 450 670 870 1150
Nall(common or
p Particleboard galvanized box)
co
ISheathing- 318 6d 240 15 360 17 460 19 600 22 335 505 645 840
I(WS"Exterior 318 86 260 18 j 380 20 480 21 630 23 365 530 670 880
Iow
Glue"
M-2"Exterior ,......_11:2- 280 18 420 20 540 22 700 24 390 590 755 980
.
Glue") 1_/2 i 106 370 21 550 23 720 24 920 25 520 770 1010 1290
I 5/8 400 21 610 23 790 24 1040 25 560 855 1105 1455
1 Nall(galvanized roofing)
I Structural 112 ! 11 ga.galv.roofing nail(0.120" 340 4.0 460 5.0 520 5.5 475 645 730
Fiberboard I x 1-1/2"long x 7/16'head)
Sheathing 11 ga.gale.roofing nail(0.120"
25/32 x 1314"long x 3 8'h"ad) 340 4.0 460 5.0 520 5,5 i 475 645 730
i
® mina!unit shear values shall be adjusted in accordance with 43.3 to determine ASD allowable unit shear capacity and LRFD factored unit resistance. For general construction requirements see 4.16. For
ilia requirements,see 4.3.7.1 for wood structural panel shear walls,4.3.7.2 for particleboard shear walls,and 4.333 for fiberboard shear walls.See Appendix A for common and box nail dimensions.
2.Shears are permitted to be increased to values shown for 15/32 inch sheathing with same nailing provided(a)studs are spaced a maximum of 16 inches on center,or(b)panels are applied with long dimension
across studs.
i 3.For species and grades of framing other than Douglas-Fir-Larch or Southern Pine,reduced nominal unit shear capacities shall be determined by multiplying the tabulated nominal unit shear capacity by the
I Specific Gravity Adjustment Factor=[1-(0.5-G)),where G=Specific Gravity of the framing lumber from the NDS(Table 113.2A).The Specific Gravity Adjustment Factor shall not be greater than 1.
4.Apparent shear stiffness values G„are based on nail slip in framing with moisture content less than or equal to 19%at time of fabrication and panel stiffness values for shear walls constructed with either OSB
^2 or 3-ply plywood panels.When 4-ply or 5-ply plywood panels or composite panels are used,G,values shall be permitted to be increased by 1.2.
tet 5.Where moisture content of the framing is greater than 19%at time of fabrication,G,values shall be multiplied by 0.5.
6.Where panels are applied on both faces of a'shear wall and nail spacing is less than 6"an center on either side,panel joints shall he offset to fall on different framing members.Alternatively,the width of the
n
i
1. `u nailed face of framing members shall be 3"nominal or greater at adjoining panel edges and nails at all panel edges shall be staggered.
ma
7.Galvanized nails shall be hot-dipped or tumbled.
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� �— --val.Mndule FAL ---
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Showing 1-100 of 119
OCase# Number Street Name Suffix Unit# Task Status Case Status Active Task
9325 yN/�'L�VV�QD DR 120 |�sued Inspections �
�� BUP2010'00100
! LI BUP2016-00101 9338 |NAPLEvVO(J[) DR 214 Issued Inspections
I. I BUP2010'00102 9339 KJAPLEVVV0D DR 174 Issued Inspections
44 L., BUP2010-00104 *r
9356 K8�PLEvV0OD DR 103 Issued Inspections ,
v
9367 MAPLEWOOD DR 118 Issued inspections
\/ L.] BUP2016-00105
JV» U �] �UP201�-001O0 9384K8APLEWOOD DR 79 Issued Inspections
���� ^ 9385 MAPLEWOOD DR 162 Issued Inspections
�_] BUP�O1�-0O107
` 9398 MAPLEWOOD DR 100 issued Inspections
e ,,‘ • r� BUP2015-001V0
9899 MAPLEWOOD DR 150 Issued inspections
n �] UB P2016-00109
�� V` 9407 MAPLEWOOD DR 138 Issued Inspections
�- 'l' —I
IP �� �UP2V18-00110
[/- 9426 MAPLEWOOD DR 67 Issued Inspections
ki
[--1 BUP2010'O0111
1..1 B0P201O'D8112 9451 �N�pLEVV0C/D DR 24 Issued Inspections
9452 MAPLEWOOD DR 55 Issued Inspections
�] BUP�O1�-OO113 `ions
9479 �APLE�O�D DR 10 Issued InspectionsFl BUP2O16-00114
�J9480 �8PLEVVO0D DR E Issued Inspections. �� BUP2016-00115
1-1 BVP2010'00118 9491 MAPLEWOOD DR 1 Issued Inspections
9492 MAPLEWOOD DR 39 Issued Inspections
�� �UP�010-U0117
12650 MAIN ST Issued Inspections
BUP3O10-00118
I:::.1 BUP2016-00094 9270 MAPLEWOOD DR 206 Issued Inspections
1.j GUP2010-00005 9271 mAPLEVV0OD DR 198 Issued Inspections
F.] BUP2O15-00090 9305 MAPLEWOOD DR 190 Issued Inspections
9304 MAPLEWOOD DR 230 Issued Inspections�� �UP�01O'00097 `inns
9322 MAPLEWOOD DR 222 Issued Inspections 1
�� BUP2016-000981
Cl
�� RER2015-00008 9338 mm~LEvvuou DR 214 Closed
i ] RER2015-00010 9304 MAPLEWOOD DR 230 Closed
i 11 RER2015-00011 9356 MAPLEWOOD DR 103 Closed
9407 MAPLEWOOD DR 138 Closed
[] RER�O15-00O12
1.1 RER2015-00013 9325 IWAPLEVVOUD DR 126 Closed
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