concrete tile shingles

Concrete Tile Roofs

Concrete tiles are a durable roofing material available in a broad range of colors, finishes, textures, and shapes. Concrete roof tiles can provide the same aesthetic appeal of clay Mission style and Spanish style roofs at a significantly lower cost, usually around $100 per square for a basic product and installation.

Although it is typically associated with warmer climates, certain concrete tiles can successfully be used to roof homes and buildings in cooler climates as well. In cold areas it is imperative to select a concrete roof tile with a low porosity, meaning one that doesn’t absorb much water. Selecting a low porosity concrete roof tile decreases the likelihood of the roof being damaged by the freeze/thaw cycle.

Concrete roof tiles are made by mixing varied proportions of Portland cement, sand, and water. The mix is molded and extruded under very high pressure. The concrete tiles are cured to the necessary strength and can be finished in a variety of ways. Color can be added and various surface treatments and glazes can be applied.

The heaviness of concrete roof tiles must be considered properly as they are much heavier than other roof systems. Fiber-cement tile is a variation of concrete tile that is lighter in weight, but a bit more expensive. A roofing contractor can advise you on the ability of your roof structure to support the weight of a tile roof. In some cases structural modifications may be required to ensure the safe installation and proper functioning of a concrete tile roof system.

Concrete tile roof systems should last upwards of 40 years when properly installed.

Caution should be used when walking on a concrete roof, especially if it is wet, as they are much more slippery than other roof types.

Installation requirements for concrete tile roofing:

Roof Deck: According to the NRCA concrete roof tiles should be applied over continuous wood decking. Plywood decking should be a minimum of 5/8 thick nominal exterior-grade plywood. For tile that has head lugs, batten and counter-batten systems may be used. Battens need to be fastened to the roof deck with galvanized, corrosion-resistant, 8d common nails at approximately 12” on center. The NRCA recommends using caution when installing a new roof onto a roof deck made of OSB, preservative-treated wood, and wood treated with a fire-retardant coating. A qualified roofing contractor can provide information on appropriate roof decking materials for your roofing needs.

Underlayment: The underlayment provides temporary waterproofing during roof installation and acts as a permanent secondary waterproofing layer to the outermost roofing material. Concrete roofing tiles are a long-lasting product and require an underlayment with a comparable service life. The NRCA recommendations for underlayment, commonly called “felt paper” specify a minimum of one layer of No. 30 asphalt-saturated felt applied horizontally in shingle fashion on roof decks having a slope of 40 degrees or more. A minimum of two layers of No. 30 asphalt-saturated felt paper is recommended for roof decks with a slope between 18 and 40 degrees. The NRCA advises against installing concrete tile roofing on roofs with a slope less than 18 degrees. For extremely cold climates the installation of an ice-dam membrane may be required. Check with a qualified roofing contractor for information about this additional underlayment.

Fasteners & Securements: Roofing nails used to install concrete tile roofs should be 11-gauge or 12-gauge. They should be made of galvanized steel or an equally corrosion-resistant material. The nails used to install concrete tile roofs should be long enough to fully penetrate all layers of roofing materials and reach into the underside of the roof deck. Nail heads should be smooth and flat with a low profile and shanks should be barbed for increased pull-out strength. Other methods of securement may be required depending on climatic and seismic factors, roof slope, local practices and building codes, and manufacturer recommendations. A professional roofing contractor will provide information as to the correct method of securement for the concrete tile roofing you select. Alternative securement and fastening methods include wire tie and strapping systems, clips, lug-hung-tile and bedding tiles.

Flashing: When installing concrete tile roof systems flashings should be installed around the perimeter edge, at any penetrations, in open valleys, and along vertical surfaces.

The NRCA does not endorse any specific concrete roofing tile or concrete tile manufacturer. At this time the American Society of Testing and Materials (ASTM) does not have any standards established for concrete roof tiles. Consulting a qualified roofing installation professional is a good way to learn about the specific concrete tiles available for your new roof.

Concrete roof tiles come with warranties against manufacturing defects. Your roofing contractor should provide you with detailed warranty information pertaining to the specific concrete roof tiles you select, as well as warranties offered by the contractor to cover roof installation.