REVIEWED BLD RESUB 1-BLD2024-0863+Structural_Analysis_or_Calculations+10.21.2024_7.02.57_PM+4572735BLD2024-0863 RESUB
Oct 22 2024
_ Structural Design Associates
Engineering Slruclures to Last
Sept. 27, 2024
Soledad Guererro
9138 186" PL SW
Edmonds, WA 98026
Subject: Alternate Holdown
SDA Ref. # 10035
To whom this may concern:
SDA 410035
.............................................
REVIEWED
BY
CITY OF EDMONDS
BUILDING DEPARTMENT
...............................................
At the request of Mark Trembach this office reviewed the subject project regarding an alternative
to the through bolt HDU4 holdown.
An alternative to the HDU4 (THROUGH) shown on the plans is a MSTCM60 with (20) 12d
common nails (strap to 4x6 DF No.2 post) and (14) 11/4" diameter x 1 1/4" long Titen Turbo Hex
head screws (strap to stem wall). A small portion of the footing will need to be removed to allow
placement of the strap. Special care must be taken during removal to keep the bearing surface of
the strap in line with the stem wall. Please see the attached schedule and detail showing the
alternate connection.
Please contact this office if you have any questions concerning this letter, or for any other
assistance.
Sincerely,
Z�4 -'0�4 ---
Chris Lalonde, E.I.T.
Chris Covington, P.E.
3006 Ruckcr Ave. Everett, WC 98201 Ph: 425-339-0293 Fax: 425-252-0916
sdaeverett.com
Structural Design Associates
Engineering Structures to Last
SDA 410035
HOLDOWN SCHEDULE
*FOR HOLDOWNS INSTALLED IN EXISTING 6" WIDE STEM
THRU BOLTS OR
EMBEDMENT
MINIMUM
MODEL
ANCHOR BOLT
NAILS/SCREWS
/ STRAP
EDGE DIST.
LENGTH
(20) 12d COMMON IN OF
TOP TITEN TURBO
MSTCM60
N/A
46 ABOVE & (14)
59Y2
SCREW 1h" DOWN
(EXPANSION)
A"00-%" 11TEN TURBO HEX
FROM TOP OF
HEAD SCREWS
I
STEM
HOLDOWN NOTES
1. ALL —THREAD BOLTS SHALL CONFORM TO ASTM A307
2. MINIMUM CONCRETE COMPRESSIVE STRENGTH f c-2500 PSI. MINIMUM WALL THICKNESS IS 6".
3. ALL HOLDOWNS REQUIRE A (2) 2x POST UNLESS NOTED OTHERWISE. WHERE HOLDOWNS ARE INSTALLED
INTO THE WIDE FACE OF THE STUD, THE STUDS MUST BE STITCH NAILED TOGETHER W/ 16d SINKERS
STAGGERED O 4" 0/C.
4. MINIMUM EDGE DISTANCE IS FOR FORMED CONCRETE EXPOSED TO WEATHER OR SOIL FOR CONCRETE
CAST AGAINST SOIL PROVIDE 3" CLEAR TO ANCHOR BOLT.
5. NALS/SCREWS TO HOLDOWN POST SHALL BE PER MANUFACTURER'S SPECIFICATIONS.
6. WHEN FIELD CONDITION BECOME LESS THAN MINIMUM SHOWN, CONTACT ENGINEER PRIOR TO PROCEEDING.
7. ALL HOLDOWN BOLTS MUST BE RE —TIGHTENED JUST PRIOR TO ENCLOSING SECOND SIDE OF WALL.
8. LONGER STRAPS MAY BE REQUIRED FOR EXPANSION ANCHORS DEPENDING ON FLOOR FRAMING THICKNESS.
WHERE A SMALLER MST STRAP IS SPECIFIED, A LARGER MST STRAP MAY BE USED (EX. MST 37 =_> MST
60). ONLY SPECIFIED FASTENERS ARE REQUIRED.
STRAPER-If",..", [fil
:'LAN NAILS PER
SCHEDULE
VIN. 4x6 DF No 2
OR PER PLAN
SOLID BLOCKING
DIRECTLY UNDER
POST
PROTECT SCREWS & STRAP RIM JOIST
WITH (2) COATS OF: APOC
AP576 ETERNA—KOTE FLAT
ROOF SILICONE COATING,
INSTALL PER MFR SPECS.
ALT: HENRY TROPI—COOL SCREWS
887 ROOF COATING PER
SCHEDULE
EXISTING FOUNDATION
EXPAN IC)N ANC/H0R
HC)LPOWN w/ RIM
3006 Rucker Ave. Everett, V,'A 98201 Ph: 425-339-0293 Tax: 425-252-0916
sdaeverett.com
Titen Turbo w/ MSTAM / MSTCM Strap (Ductile Design LRFD)
Date: 9/27/2024 Engineer: CRL Job:10035
REAR
LRFD Holdown w/o Do
Demand
Capacity
Connection Design:
Strap per Simpson
4471
5692
lbs.
79%
P
4471
lbs.
Titen Turbo
4471
5692
lbs.
79%
Z
105
lbs.
Ta. 12P Nos
Fasteners (NDS)
4471
4533
lbs.
99%
Z'
227
lbs.
Strap Per AISC
4471
5832
lbs.
77%
Kf
3.32
2
0.50
# Titen Turbo 1/4" x 1 3/4" Hex 14 14
CM
1
Ct
1
Simpson # of Fasteners:
20
MSTCM60
Cg
1.00
NDS 2018 # of Fasteners:
20
20
n
Model No.
Fasteners:
Capacity:
Screws:
REA
MSTAM24
7
1956
5
Es
29000000
psi
MSTAM36
14
2522
8
.148"(D
Em
1600000
psi
MSTCM40
26
5692
14
x3.25"
As
0.29
in^2
MSTCM60
20
5692
14
Nails
Am
10.5
in^2
m
0.94
1.00
Component Strength
u
(LRFD)
Limit:
s
1.5
in
Titen-HD
5x3.75
1 0
Conc. Breakout
v
15373
(6"
down from top of (6")
wall )
Limit:
T-Yielding
T-Rupture
Bearing
Tearout
D
0.148
in
MSTCM
Strap
Fasteners:
(LRFD) (kips)
CA
1
5.832
Ceg
1
5.873
Cdi
1
14
21.924
Ctn
1
16.443
m
0.7
A
1
D2:
(a) Tensile Yielding of Strap:
(�t 0.9
Pn Fy*Ag
Fy 36 ksi
Ag 0.18 in^2
(�tPn 5.832 kips
(b) Tensile Rupture of Strap:
�t 0.75
Pn Fu*Ae
Fu 58 ksi
Ae 0.135 in^2
(�tPn 5.873 kips
(1)
(2)
Rn
d
t
Fu
4)Rn
Rn
Ic
t
Fu
(ORn
J3.10
0.75
Bearing
Tearout
@ Bolt:
2.4*d*t*Fu
0.25 in
0.06 in
58 ksi
1.566 kips/Screw
@ Bolt:
1.2*lc*t*Fu
0.375 in
0.06 in
58 ksi
1.175 kips/Screw