Currently, we do not install tile because we do not agree with the procedures in the FRSA installation manual.
Unfortunately both clay and concrete tile manufacturers are very deceiving with their warranties. Clay and concrete tiles are the only products except wood shakes that the manufacturers do NOT have an installation manual for, and do not warrant their applications. These installations are as close to “buyer beware” as is possible. These systems are put together with approved pieces, but most have never been tested or approved as a system. Although most of the tiles carry a 50 year warranty, this warranty does not cover roof leaks. Some of the concrete tiles require maintenance of the products. This maintenance also frequently leads to broken tiles and problems.
Some of the better clay tiles are impervious to water, and have installations that have performed for extended life expectancies of over 50 years. In fact we have a few tile installations on Davis Island and in the Bayshore area where we removed the old tiles that were over 50 years old, replaced the flashings and felt, and reinstalled the same tiles. A couple of the better known applications where we reused the tiles are on the old chapel at the Academy of Holy Names, and the Catholic Diocese in St. Pete. Concrete tiles on the other hand are NOT impervious to water, and once the glaze has worn off, they will actually absorb water. The old Duntex Florida tiles used to be installed in concrete over a 30#/90# sub roof. The new concrete tiles are too heavy, and do not bond properly to concrete for that application. Many of the roofs in the New Tampa area have slid off because they were installed in this manner.
The concrete tiles we know in Florida today were designed and brought over from Australia. They were originally used in Texas and California without any sheeting or sub roof because they were thought to be waterproof. They were fastened to 1″ by 4″ strips that were installed to the rafters. When Morris Swope was writing the Southern Standard roofing division, the tile manufacturer brought his son Keith to Texas to approve the application for the new codes. Once he saw the problems they were having such as leakage from broken tiles, flashing details, and the problems with the flat tiles, they required the tiles to be fastened through a sub roof to be installed to meet code.
After monitoring the performance of this application, we have come to the conclusion that there are many problems with this application. Not only do the tiles absorb water and eventually rot out the 1″ by 4″ battens used to secure them, there are problems in the valley areas. The tiles are designed with lugs on the back to strengthen the tiles which does not allow them to lay down properly with the hooked metal, the most common and easiest way for people who go onto the roof is to walk up the valley. When you use the metal “W” valleys which are required on mechanically installed systems the metal crushes and fails. The newest and most promising system is to foam the tiles on. We would prefer to mechanically install the tiles, but with the system specifications that is code today. We can’t recommend that application. The next best option is to foam the tiles on.
There are still some pitfalls when foaming tile on. The foam that we use today is only been around for around 15 years, and it is still evolving and perfecting the system. There are two types of foam systems, one option is a two part system. If you use this system, the applicator must properly mix the formulas on site, and the mixture is very humidity sensitive. If there is a flaw built into the system, you can be assured that the blame will be put on the applicator, who may or may not be able to afford to correct the problem. The other option is a pre- made solution that all the applicator has to do is to point and shoot. It’s a little more expensive to do so, but if you use the right sub roof, and the right foam, you can get a tested assembly that can receive a manufacturer’s 20 or even 30 year warranty on the complete assembly.