Measure the total rise from the deck surface to the ground
Determine the number of steps by dividing the total rise by the desired riser height
Adjust the riser height so all steps are equal
Calculate the tread depth for each step
Choose stair width based on the deck opening and use
Check local building codes for stair dimensions, landings, handrails, and footings
Mark the stair layout on a stair stringer board
Cut the stringers with a framing square and stair gauges
Test-fit the stringers against the deck
Install a ledger or support block if needed at the deck attachment point
Secure the stringers to the deck framing with approved fasteners and hardware
Set the bottom of the stringers on a concrete pad, footing, or landing block
Add additional stringers for wider stairs
Attach stair treads to the stringers with exterior-rated screws or nails
Install riser boards if building closed stairs
Ensure each tread is level and each riser is consistent
Add blocking or bracing as needed for stability
Install posts and handrails where required
Add balusters or infill that meet code spacing requirements
Treat cut ends and exposed wood with preservative or sealant
Inspect the stairs for secure connections and even step dimensions