Installation Guide
42
HOW TO INSTALL DECKING
NOTE: Construction methods are always improving. Please refer to www.trex.com for the most up-to-date installation requirements.
LOCATION AND INSTALLATION OF SURFACE MOUNT POST – DECKING/
CONTINUED
Install Railing System of Choice
NOTES: 
» Quantity of 18 self-tapping screws are provided to 
cover all types of Trex railing bracket installations 
(Transcend, Signature [formerly Reveal], and Select). 
Thus depending on the type railing being installed, you 
may have screws that are not used.
»  If using 6x6 post sleeves, attach designated railing 
brackets using #8-15 x 1-3/4" (4.4 cm) 316 stainless 
steel self-tapping screws (
not provided
).
»   Pre-drilling is not required but is optional for 
attachment of brackets to guide blocks. Use a drill 
bit slightly smaller in size than that of screw being 
installed.
NOTE: If installing Trex DeckLighting on the posts, 
drill hole through support blocks to allow wiring for 
lights to be below the surface of the decking.
LOCATION AND INSTALLATION OF IRC-APPROVED POST MOUNTS – CONCRETE
IMPORTANT NOTES:
» INSTALLATION SHOWN HERE IS FOR IRC APPROVED 
APPLICATIONS ONLY.
» MAKE SURE CONCRETE IS LEVEL BEFORE INSTALLING POSTS.
» ALWAYS REFER TO YOUR LOCAL BUILDING CODE OFFICIAL 
PRIOR TO INSTALLING ANY RAILING SYSTEM TO ENSURE ALL 
CODE AND SAFETY REQUIREMENTS ARE MET. TREX CANNOT BE 
HELD RESPONSIBLE FOR IMPROPER OR NON-RECOMMENDED 
INSTALLATIONS.
» CANNOT BE USED WITH TREX TRANSCEND COCKTAIL RAILING.
» See page 53
 for sku information.
TOOLS NEEDED
» 
Hammer
» 
Drill and/or screw gun
»  
3/8" (10 mm) drill bit for concrete
PARTS
» (1) Post mount
» (2) Guide blocks
» (18) #8-15 x 1-1/4" (32 mm) 
Self-tapping screws
» (2) 10 x 1" (25 mm) 
Self-tapping screws
SKU ALPOSTHWCONC 
(this SKU SOLD SEPARATELY)
» (4) 3/8" x 3-3/4" 
(10 mm x 95 mm) 
Expansion anchor
» (4) Flat washers
» (4) Hex nuts
Pre-drill Holes
1.   Using post as a template, mark locations of the four 
holes and drill into concrete at least 2-5/8   " (66.7 mm) 
using a 3/8   " (10 mm) masonry bit.
NOTE: You can either set drill bit to correct depth on 
drill or mark drill bit with tape at required dimension to 
ensure all holes are drilled at the correct depth.
1
3/8"
 (10 mm)










