Installation Guide
Page 4
Excessive Construction Debris
It is important during construction, the deck’s surface stay 
clear from excessive build-up of dirt, sand, and dust from tile, 
concrete, landscape blocks, or any other masonry products. If 
these materials are not removed immediately, the deck surface 
will become difficult to clean and can potentially damage the 
deck’s surface finish. 
Do not use AZEK Deck as a work surface.
When installing AZEK Deck on a new home, best practice is to 
install after all other construction (siding, roofing, painting, 
etc.) is completed, otherwise permanent damage may occur.
If a build-up does occur please refer to the Care and Cleaning 
section in AZEK’s installation guide or website, AZEK.com. 
IMPORTANT: Do not allow airborne dust from concrete, 
landscape blocks, or any masonry product to accumulate on 
the AZEK Deck, Porch, Rim Joist Covers, & Riser surface as it 
may damage the surface of the deck. Do not cut any product 
on or near AZEK Deck, Porch, & Rim Joist Covers.
Installation Preparation
Follow these guidelines for best deck installation:
• AZEK Deck Boards are one-sided products. Deck Boards are to be installed with the grain side up for the walking 
surface. 
• AZEK Rim Joists Covers are one-sided. Rim Joist Covers are to be installed grain side out. 
• As joists are installed, run string line frequently to ensure that the tops of the joists are in plane, as AZEK Decking 
will conform to the contour of the joists to which it is attached. It may be necessary to shim or plane joists due to size 
variations in lumber. Be sure to sort and exclude any extremely crowned joists/lumber material.
• Prior to installation, check to make sure all joists are level, structurally sound, and there are no nails or screws 
protruding.
• Proper joist spacing is required for proper installation. Joist spacing should never exceed 16” on center. For a more 
rigid feel, 12” may be preferred. 
• Install solid wood blocking between each joist, placed in rows at maximum every 4’ - 6’ within the structure using 
exterior grade screws. Solid blocking will help reduce up or down movement and/or twisting of joists. Limiting joist 
movement can help reduce excessive gapping and also ensure a more uniform finished surface of the AZEK Deck.
16”BASIC INSTALLATION 
SUBSTRUCTURE
16” on center maximum joists.
(12” on center for commercial 
applications)
PICTURE FRAME INSTALLATION 
SUBSTRUCTURE
16” on center maximum joists plus 
additional support for picture frame 
structure (12” on center for commercial 
applications)
DIAGONAL INSTALLATION 
SUBSTRUCTURE
12” on center maximum joists.
More severe angles may require closer 
joist spacing. 
1 2 3
16”
16”
12”
Working with AZEK
®
 Deck Boards










