My husband is asking for bids to have masonite siding that was installed when our house was built in 1978 replaced with vinyl or aluminum siding.e siding removed from our 26 year old house and replaced with vinyl or aluminum siding. Today an estimator told him that masonite contains asbestos and that special steps must be taken to safely handle the material. We've never heard that masonite may contain asbestos or be an unsafe product. Is the installer attempting to justify jacking up the tear-off expense or is asbestos in masonite a well kept secret? Any information on this subject would will be appreciated.