
Reference Guide & Assembly Instructions
Congratulations and thank you for your purchase!
Fortis® is an easy-to-install aluminum deck board with a hidden fastener system. This Fortis installation guide provides general instructions for the installation of the 8” Fortis board. If you have any questions along the way, please don’t hesitate to call Customer Service toll-free at 877-270-9387 or visit our resurce library.
Please read these instructions in their entirety before you start your project and be sure to follow these steps carefully to ensure the durability and safety of your deck.
Tool Requirements

Tape Measure

Drill Driver

Circular Saw Or Miter Saw

Carbide Tip Steel Saw Blades

#10 x 2 1/2 Stainless Steel Sheet Metal Pan Head Fasteners

Work Gloves & Safety Glasses

Rubber Mallet/Hammer

Caulk Gun & Exterior Flashing Sealant

Framing Square
How It Works: Installation Overview
Structural Recommendations
ALWAYS CHECK WITH YOUR LOCAL MUNICIPALITY ON PERMITTING AND ALWAYS CONSULT A PROFESSIONAL ENGINEER TO ENSURE CODE COMPLIANCE.
Framing
The structural frame drawings in this guide are intended to illustrate the support requirements of Fortis and are not to be considered as a recommendation for actual deck construction.
Fortis will be fastened directly to the perimeter framing on all sides and all 16” on center common joists.


Ledger Flashing
IMPORTANT! Ensure that the ledger board and flashing have been secured properly and are free from debris such as protruding nails or screws.
Components

Fortis Board
The structural frame drawings in this guide are intended to illustrate the support requirements of Fortis and are not to be considered as a recommendation for actual deck construction.
Fortis will be fastened directly to the perimeter framing on all sides and all 16” on center common joists.

Fortis Clips
Fortis boards are secured to the joists by a hidden fastener system. The half inch tall Fortis clips attach between the Fortis boards in the grooves and screwed into the top of the joist using the included trim-head screw fasteners.

Trim
Fortis trim can be cut to any length up to 24 feet and gives a finished appearance to the ends and sides of your Fortis deck.

2"x2" Rigid Flashing
Wahoo Building Products provides a color-matched rigid flashing that is installed where the deck attaches to the structure and provides both protection from water infiltration to the below structure as well as a finished look to your Fortis deck. It measures 2 inches by 2 inches and is attached using the T-25 torx trim head screws (provided.).
Deck Installation
Step 1: Layout And Hidden Fastening System
- Fortis deck boards can be cut to their desired length prior to installation or after installation. Wahoo recommends pre-cutting to length with a stationary miter saw to ensure a clean cut with no obstructions.
- To begin install, the start board face mounts near the outer edge of the header board with stainless steel fasteners. (Not included)

Face mount with stainless steel fastener. (Not Included)
Use groove as a guide.

You may need to pre-drill to help keep screw from “walking”.
Step 2: Install Decking
- After placing the Fortis boards on the frame joist, attach the Fortis clip into the Fortis boards’ grooves.
- Using the provided Fortis clip screws, secure the boards with the Fortis clips while being careful to not over torque the screws in the wood joists.


Repeat this step until you reach the final board. (See Fig. 5-1 and Fig. 5-2)

Fig. 5-1

Fig. 5-2
Step 3: Installing Final Board
When it is time to install the final board, face mount with a stainless steel fastener (not Included) to the outer edge of the board.

Face mount with stainless steel fastener.
(Not included.)
Step 4: Installing Trim
Cover the perimeter of the Fortis deck with its color matched trim which will conceal the cut ends and sides from view. It also adds a “finished” appearance to the whole project.
(See Fig. 6-1 and Fig. 6-2)

Fig. 6-1

Fig. 6-2
Use the supplied Torx pan head screw to attach the finish trim.
(See Fig. 6-3 and Fig. 6-4)

Fig. 6-3

Fig. 6-4
Step 5: Installing Rigid Flashing
This flashing is in addition to standard ledger flashing
Using the Torx pan head screws, install the 2 inch by 2 inch (2”x2”) color matched rigid flashing to the exterior of the structure. This will beautify the deck by giving it a more “finished” look. It will also further add a layer of water intrusion protection.
Always apply flashing sealant to the back and bottom sides of the rigid flashing prior to installation.
- It is ideal to install the rigid flashing behind a lap of siding whenever possible, when lap siding is present.
- This flashing is in addition to, not in lieu of, standard ledger flashing.
