Installation Guide
41
HOW TO INSTALL DECKING
LOCATION AND INSTALLATION OF SURFACE MOUNT POST – DECKING/
CONTINUED
Line Post Installation 
3.   Install two 2
"
 x 8
"
 (5.1 cm x 20.3 cm) cross bracing 
frames in between joists at 7-1/4
"
 (18.4 cm). Attach a 
total of twelve 3
"
 (7.6 cm) pressure-treated compatible 
screws (not provided).
4.   Install two 2
"
 x 8
"
 (5.1 cm x 20.3 cm) boards as 
blocking under post location. Securely attach 
blocking using a total of twenty-four 3
"
 (7.6 cm) 
pressure-treated compatible screws (not provided).
5. NOTE: RIM JOIST REMOVED TO SHOW PROPER 
ATTACHMENT OF HARDWARE. 
Insert the (2) 
stainless steel barrier 
strips under the 
mounting bolt holes.
Use composite shims 
or similar material 
(not provided) if posts 
are not plumb. Ensure 
that post is placed 
on decking surface 
so that it clears the 
rim joist and there 
is enough clearance 
on the underside 
blocking for the back 
plate to be installed.
Attach posts using four 3/8" x 6" (1 cm x 15.2 cm) 
hex cap bolts, washers, and nuts, along with aluminum 
back plate on underside of blocking. If the project 
requires IRC compliance, this back plate MUST
be installed under the decking to ensure this will 
meet code compliance. Reference SKU part number 
ALPOSTHWDECK for required hardware and aluminum 
plate. (Consult local code offi cial for more information 
on IRC Compliance.)
Install Guide Blocks
NOTE: Pre-drilling is not required but is optional for 
attachment of guide blocks to post. Use a drill bit slightly 
smaller in size than that of screw being installed.
6.   Place or rest bottom aluminum guide block on 
bottom of post. Place guide on post so that notch is 
on a side that does not require railing to be attached.
7.   Attach bottom guide block using one 10 x 1” self-
tapping screw (provided) in notch to lock guide block 
onto post.
8.    Location of top guide block will vary slightly based on 
type and height of railing being installed. Determine 
this measurement and place top guide block in 
location where top bracket for desired railing would 
be approximately on center of the top railing bracket 
location.
9. Attach top guide block using one 10 x 1” self-tapping 
screw (provided) in notch to lock guide block onto 
post. 
4
Blocking
boards
5
barrierbarrier
7-1/4
"
(18.4 cm)
7-1/4"
(18.4 cm)
3
Cross bracing 
frame
Cross bracing 
frame
6
notch
8
notch
7
9










