1566_001Ccivil & structural
ENGINEERING engineering & planning
MEMORANDUM
To: Phillip Dienes (Walls and Weeds, Inc)
From: Joe Galusha, PE, SE Associate Principal
Date: July 16, 2021
Re: Herzig Residence — Holdown Substitution
During construction, difficulties were encountered in attempting to install the anchor rods for the HDU8 holdowns
shown in the holdown schedule and noted on plans. The client and contractor asked CG engineering for an alternative
holdown strap that could be installed and anchored to the side of the concrete stem wall to eliminate the need to drill
and epoxy the anchor rods as shown on detail 1/53.1 of the structural detail sheets.
We have determined that (2) Simpson Strong -Tie MSTCM40 holdown straps side -by -side with a minimum of (10) %"x1-
3/4" Titen 2 screws into the side of the concrete stem wall each strap, and a minimum of (14) 0.148" x 3-1/4" nails into
the wood stud each strap may be substituted for (1) HDU8 holdown. The straps will be nailed to (1) existing vertical
stud, and (1) new flat 2x6 stud. Both studs shall be attached to the shear wall sheathing with full panel edge nailing.
install holdowns per recommendations by manufacturer.
G.
5 �-44'
al
ANAL
ATTACHMENTS:
'*IIbl a 1
• Excerpt of Simpson Strong -Tie Wood Construction Connectors Catalog 2019-2020 (pg. 250)
DISCLAIMER
This recommendation is the professional opinion of CG Engineering PLLC based on the Information provided. This memo was prepared subject to the standard of care
applicable to professional services at the time the services were provided.
250 4th Avenue South, Suite 200
Edmonds, WA 98020
ph, 425.778.8500 1 f. 425.778.5536
www.cgengineering.com
Y
250
MSTAM/MSTCM
Strap Ties
MSTAM and MSTCM models are designed for wood -to -masonry applications.
The MSTC series has countersunk nail slots for a lower nailing profile.
Finish: Galvanized. Some products are available in stainless steel or ZMAX® coating.
See Corrosion Information, pp.13-15.
Installation:
• Use all specified fasteners; see General Notes
• Attaches to grouted concrete block and wood framing
• Minimum end and edge distance for Titeno' screws is 1'/2" j
Codes: See p.12 for Code Reference Key Chart
These products are available with additional corrosion protection. For more information, see p. 15.
Masonry and Concrete Applications
Dim.
Fasteners
Allowable Tension Load
Model
(in.)
(in.)
DF/SP/SPF/HF
(160)
No.
Ga.
Rode
f.
W
L
Nails
GFCMU
Titen® 2
Concrete
Titen®2
GFCMU Concrete
MSTAM24
18
1 %
24
(9) 0.148 x 3
(5)1/4 x 2'/4
(5) %4 x 13/4
1,375
1,460
MSTAM36
16
11/4
36
(13) 0.148 x 3
(8)1/4 x 21/4
(8)'/4 x 13/4
1.870
1,870
FL
MSTCM40
16
3
40'/4
(26) 0.148 x 3'/4
(14)'/4 x 2'/4
(14) 1/4 x 13/4
4,220
4,220
MSTCM60
16
3
591/2
(26) 0.148 x 3 %4
(14)'/4 x 2'/4
(14) ;A x 13/4
4,220
4,220
See footnotes below.
Floor -to -Floor Clear Span Table
Fasteners (Total)
Allowable Tension/
End
Clear
(in.)
Uplift Loads
Model
No.
Length
Span
Code
Ref,
DF/SP
SPF/HF
(in.)
(in.)
Nails
GFCMU
Concrete
(160)
(160)
7iten° 2
Titen° 2
MSTAM36
81/4
16 or 18
(7) 0.148 x 3
(4)1/4 x 21/4
(4) 1/4 x 11/4
1,400
1,210
MSTCM40
171/e
16 or 18
(14) 0.148 x 3'/4
(10)114 x 2Y4 1
(10)1/4 x 13/4
2,800
2,420
FL
MSTCM60
171/e
221/4
(26) 0.148 x 31/4
(14)1/4 x 2'/4
(14)'/4 x 13/4
4,220
4,220
MSTCM60
17''A
26'/4
(20) 0.148 x 31/4
(14)'/4 x 21/4
(14)1/4 x 13/4
3,840
3,320
1. Loads have been increased for wind or earthquake loading, with no further increase allowed.
Reduce where other loads govern.
2. Minimum edge distance for TltenO 2 screw is 1'/2".
3. Concrete shall have a minimum compressive strength of f'c = 2,500 psi.
4. Grout -filled CMU (GFCMU) shall have a minimum compressive strength of f'm = 1,500 psi.
5. Products shall be installed such that Titena' 2 screws are not exposed to the weather.
6. See p. 338 for Titen® 2 screw information.
7. Fasteners: Nail dimensions in the table are diameter by length. Titen 2 concrete/masonry
screws are Simpson Strong -Tie masonry screws. See pp. 21-22 for fastener information.
11/2
Totol
Masonry
o L 401/4" o
0
I--6. 17/s
o }
3"
�i
o
0 0 0
2" typ• 0 0
o 0
0 0
1/z" —. t 3 y
MSTCM40
MSTAM36 (other MSTCM
similar)
Typical MSTAM36
Installation
Mn
m