[72chevy4x4]

I'm bidding a job and looking for some input on installing new vinyl siding over an existing 12" lap fiber board. The material if not exactly particle board, but close to it with a 10.5" reveal and seems to be pretty thin at ~1/4" thick. My first though is fanfold and install a new premium vinyl over top-but the concern is upon nailing through the board with ring shank nails, will the lap board hold or blow out?

I'm not familiar with siding has the marked nailing flange to nail into the stud (maybe Certainteed siding)-anyone used that in an installation such as this where the nailing surface below wasn't stellar? Under the exisitng fiber siding is 1/2" foam board-then studs.

[Patrick]

Half inch foam, and nail on the studs. use lat strips as needed to fill pockets created by old lap siding

[Grumpy]

I was at a certainteed siding "pro dialog" meeting and I just about blew up on a guy regarding installing siding over siding. More often than not we tear off what's there even if it is suitable to go over.

You might consider bidding the pre-insulated if you go over.

YOu may have some degree of breakage on the fiberboard depending where your nails land, and yes nail through the siding and into the studs ALWAYS.