Fiber Cement Absorbs Water
The main problem with fiber cement siding has to do with the ingredient cellulose--which is essentially just sawdust or wood pulp. Inevitably every house has an area of siding that comes close to or in direct contact with a surface that collects or passes water, snow, or ice. (decks, roofs, walkways, and driveways). In these areas fiber cement siding may absorb moisture. This leads to swelling, crumbling, delamination between layers, and loss of paint adhesion
The Paint on Fiber Cement Sometimes Peels
In areas where fiber cement has absorbed moisture directly or endures consistent back splash, the surface paint may start to peel prematurely. Fiber cement siding is not colored through, so what's revealed when the paint peels is the raw material which is a grayish color. These peel spots are particularly easy to spot when in contrast to a dark or bright colored paint.
Fiber Cement Siding is Difficult to Install Properly
If the possibility of peeling paint and crumbling siding in areas of moisture isn't alarming, you should also know that fiber cement is incredibly difficult to install in exact compliance with the manufacturers' guidelines. Some manufacturers installation manuals are over 150 pages long. If the siding is not installed exactly to specifications your warranty may be void and you will have little recourse if you ever have product issues in the future. Given the recent popularity of fiber cement siding, there's an abundance of contractors installing it who do not have sufficient experience or training to adhere to the stringent installation instructions required to keep your warranty intact.
If you're considering alternatives to fiber cement siding, then you'll definitely want to consider Everlast Composite Siding (Polymeric Cladding).