Once you can reach the heel carefully measure the height of it vertically at the outside corner of the wall to within 1 8 inch.
Attach small gable to wood siding.
This is due to the fibrous siding material s weakening over time as stress is placed on the material from the awning.
If your siding is not beveled you can simply screw the ledger tightly to it.
Screw in louver with construction screws.
Wood product siding can be manufactured from medium density fiberboard high density fiberboard osb solid wood or plywood.
If you have beveled horizontal siding then use an inverted piece of siding as shown in the illustration here to create a plumb flat surface for attaching the ledger.
If the wood siding is beveled or lapped you will need vertical furring strips 16 inches apart covered with rigid foam board to provide a flat surface.
Grab your tape measure and find the center and mark accordingly.
Another way would be to pull off some siding at the top of the wall on the gable end right where you are going to be starting the addition.
For mdf or hdf the awning should be mounted in the same fashion as with cement siding.