Product has real problems. Company does not back product unless you put it in according to the letter of the law.
Ventilation is a big issue. When product was installed in 2002 was alot of unknowns. Now the unknowns have come back to haunt the Tendura Company. My advice is leave the product on the shelf you don't need the problems that it has. And don't look for help from Tendura when failure happens.