Q:
My house has cedar wood lap siding which looks good, but the north side of the house takes some pretty rough weather. I don't want to repaint again, but I wonder if it would be okay to put either vinyl or metal siding over the cedar wood lap siding? I'm thinking it might act as sound barrier if I kept the old siding on but I'd probably have to put on a plywood sheathing first for it to be a smooth surface. Can you tell me if this idea is practical or economical?

The only type of siding I do not recommend covering is Cement Asbestos shingles. In that case, covering the siding means nailing through and crushing the asbestos shingles which can release it into the air and potentially end up as a big toxic mess for any future homeowner that needs to replace or even repair the vinyl siding.
The only down side to putting vinyl over wood is that since the siding is about an inch or so thick, areas around windows and doors may appear recessed behind the J channel that would be used as trim. That being said, it is still not worth the cost of stripping off the old siding.
As to sound proofing the siding, residing vinyl siding will not significantly reduce sound transmission so that need not be considered when adding the siding over the cedar wood lap.
Answer by: Tom Kraeutler