If not opting for the interlocking deck tiles you ll need to place sleepers on both surfaces.
Front porch deck over concrete.
Cut pvc trim boards to wrap around stoop using circular saw.
You would then place your wood porch flooring over the sleepers.
Drill holes through each counterbore.
To cover the ends of the sleepers install deck fascia board.
Another option of course is to remove the concrete entirely and rebuild the porch from the ground up.
Counterbore holes in pvc trim with inch diameter spade bit.
Thick pvc trim 3 16 x 3 1 4 in.
Installing a multi color deck over concrete if you re installing two different colors of boards for your deck then you can screw the accent color boards into place temporarily to act as guides for the primary color boards.
Concrete screws decking flashing tape plastic shims self leveling compound treated 2x4s.
You could only do this if there is sufficient space between the existing slab and your door otherwise the flooring would prevent the door from opening.
Apply foam adhesive to back of trim.
If the damage to your concrete patio appears too far gone consult with a local trexpro.
Run bead of hot melt glue across miter joints and press trim board against stoop.
Instead of removing those concrete front steps save some time by building a wood deck over and around them.