Some installers insist on counterbatten systems to ensure moisture drainage. Because battens are elevated off the roof, water from wind-driven rain is blown under the tiles where it migrates to the eaves and leaves the roof. The number of nail penetrations of the underlayment is far less with a counterbatten system which has been the standard for low-slope tile roofs and tile roofs in cold weather climates.

Counterbatten systems have other advantages as well. The air space between roof deck and tile creates a thermal barrier that cools the structure in hot climates and minimizes ice dams in regions with severe winter weather - this is optimized in a counterbatten system, adding significantly to a reduction of ceiling level heat over a typical tile roof installation. Counterbattens are not recommended in high wind areas.

In cold weather climates there is always the risk of an ice dam, which is a ridge of ice that forms at the roof's edge, preventing snow from draining off the roof. This has serious implications as the backed up water can leak into the structure, causing significant damage. Ice dams can form because the heat lost through the structure's roof melts the snow on the surface, causing it to flow down the roof but freeze at the eaves. Even if there is heat rising from the attic, the counterbatten system has created the sufficient air space beneath the tile to dispel the heat before it can melt the snow.

The slope of the roof will often determine whether a batten system is used. On steeper pitches a batten system is required by code. Designing a lower sloped roof can be more cost effective due to reduced labor and materials requirements.

Flashings
Every roof penetration such as vent pipes, dormers, chimneys, and skylights requires two flashings. The first flashing is installed with the underlayment and the second is integrated with the tile. Tiles should be cut close to the pipe, with a space open below the pipe to prevent debris accumulation. Vent pipe sealing options include adhesive, mastic or a pipe collar; flashings may be painted to match the tile.

 

Counterbatten Installation System

Note: Consideration should be given to climate and roof orientation to determine if it is beneficial to specify/use vertical battens over underlayment, with horizontal battens secured over the vertical battens.

Source: Tile Roofing Institute. Installation Manual for Moderate Climate Regions

 

 

Blended Installation
Multiple shades of tile in either random or set patterns are referred to as "blended" tiles. They create distinctive roof designs especially in the custom home market and are becoming increasingly more popular. Either two or more solid colors can be selected and blended on site; another option is to purchase factory blended tiles where multiple colors are delivered to the job site on a single pallet.

Both methods require the contractor and architect to examine closely the tile distribution on the roof so that the effect is aesthetically pleasing. Poor layout can cause "hot spots," where tiles of the same shade are clumped together - an unpleasing patch of color that can result in additional labor to correct. Proper roof tile loading and application are essential for successful blend applications and meeting the expectations of the architect and owner.

Conclusion
Sustainable and aesthetically pleasing, a concrete tile roof can be an attractive, cost-effective addition to any building. A known manufacturer with a strong warranty, a climate-appropriate product and a qualified roofer specializing in concrete tile roofs are essential to a trouble-free, long-lasting experience for architects, builders and owners.

Hanson Roof Tile, with plants in California, Arizona, Florida and Texas, manufactures concrete roof tile in a variety of styles and colors appropriate for residential, commercial and re-roofing applications. Hanson concrete roof tiles last a lifetime, add curb appeal and can be used for cool roof applications. www.hansonrooftile.com