Installing Hardiplank Siding Over Existing Siding

Installing vinyl siding over wood siding wood must be sound.

Installing hardiplank siding over existing siding.

It s recommended whether you choose new osb or your current siding if it s in good shape and installed to the studs. Vinyl siding must be installed against a flat surface. The hardie website is unclear on this issue. Thank you for any information.

Existing wood siding must be in good shape with no rot or mold and fastened tightly to the wall. If the wood siding is beveled or lapped you. Does this mean that hardieplank cannot be installed directly over existing wood siding without voiding the warranty. The first course of any wall should be installed over a 1 4 lath strip to ensure a consistent plank angle see figure 1.

The best way to get the performance you expect from your james hardie products is to work with a professional contractor. Optionally install the lap siding with a maximum 1 8 gap and caulk the joint see detail at right. Without properly inspecting and examining your current siding it s probably hard to tell its actual condition. This would be on an older house but the wood siding is in good condition.

Using existing siding for replacing siding the best place to start is to closely examine the existing siding to get a good understanding of what condition it is actually in. Why siding over existing siding is a bad move. If hardie is installed too close to these surfaces there is a chance that the paint will start to bubble and peel. Now you probably want to know just how you re supposed to decide.

Keeping your existing siding. Install hardiplank siding with joints butted in moderate contact. James hardie siding is made of cement so it will absorb moisture if it is installed like this. Several contractors have suggested that the wood siding need not be removed.