The best thing to do and it s the code in va is to put aluminum coil in between the wood and the concrete.
Concrete patio against siding.
Concrete absorbs and holds water and most siding and trim materials including fiber cement aren t rated for contact with concrete.
Large roof overhangs can provide protection in some cases.
It is unknown what type of water insect access is available occurring under the siding below the surface level of the cement.
You are right to be concerned about placing the new concrete step in direct contact with the fiber cement trim or most siding and trim materials for that matter.
Typically when i pour concrete against a house foundation never pour concrete against any siding imho it invites trouble later i have an expansion joint set to the house.
If you find your plans require laying pavers against vents siding or other materials choose another patio plan.
Observed non standard installation of concrete on the patio see photo this section.
It can be cork 1 2 thick by 4 tall set to the wall with short pins to hold it while pouring.
Other times an l flashing over the surface of the concrete and work but keep in mind this can also trap moisture behind the the concrete.
Editorial advisor mike guertin replies.
Sometimes with the siding trim and door out of the way a flashing can be slid in between the house and the concrete.
Starting at foundation not siding you can install pavers against your house foundation as long as it is the foundation itself.