Can I install a tile roof over a 4 year old shingle roof as the underlayment? It is a truss roof with 1 x 12 deck boards.
The issue of tile installed over asphalt shingles has been raised many times over the years. There is no test data available for this specific situation that we know of, and there probably won?t be because of the varied circumstances. It is reasonable, however, to consider asphalt shingles in good condition as an upgrade to a Type 43 underlayment for a batten installation. The following conditions must also be considered: ? Trusses must meet the requirements for the additional weight. ? Deck must be free of dry rot and the shingles must be less than five (5) years old. ? Local codes. Tile over shingles conforming to the above criteria and done according to the published specifications for a batten application should provide a long-lasting installation. The issue of tile installed over asphalt shingles has been raised many times over the years. There is no test data available for this specific situation that we know of, and there probably won?t be because of the varied circumstances.