Should James Hardie Plank be installed over wood siding or vinyl siding ?
James Hardie BP makes a great variety of exterior cement products such as hardieplank lap siding or fiber cement clapboard, hardieshingle, hardiepanel also know as hardie vertical siding and all kinds of cement trim board and cement board soffit.
In order to have the best value of fiber cement panel the existing wood siding, vinyl siding or aluminum siding must be stripped off from the house.
Differently from pvc siding, hardie products are heavier so it’s better to be installed closer from the studs. The wall is already ½” to ¾ build out because of the existing product and if the owner want to use any kind of insulation (it could be from 3/8” to 1” thick) it will built out the wall even more.
Another factor to be considered is the existing condition of the existing product on the wall. Wood siding tends to get warped making the wall not completely even and flat compromising the installation of James hardie panels.
Vinyl siding is composure of PVC material which means it will contract depending on the temperature. The nail used to install James Hardie cement board siding will not allowed the existing vinyl siding to move so once it begins to pop out the new james hardie plank siding will pop out too.
So the answer is NO. You must strip the extisting siding in order to install a new James Hardie Fiber Cement Siding.