In the old days when the owner was provided with a 20 year bonded roof the assumption was that the roof was guaranteed for 20 years. Well, yes and no. The roofer provided a 2 year guarantee and was responsible for making good any defects that appeared in the first two years. After the first two years the manufacturer would pay the roofer to make any defects good for a period of time. To have this type of guarantee in place one had to make sure to follow the rules which were simple. Advise the manufacturer in writing of any defect within x number days of a problem, do not alter the roof in any way without permission from the manufacturer, do not change the use of the facility, and so on. Well, some owners were very good and followed all of the rules and when they had problems they met with their legal counsel. Ah, but the 20 year bond lacks the 20 year flashing endorsement on the back of the Bond. How can you expect a roof to last 20 years without 20 year flashings? Ah, but the bond does not cover the insulation or vapor barrier and insulation, etc. below the roof membrane. Well, first you must prove that the failure was from the top down and not the bottom up. If the failure was from the bottom up it was not covered. These issues provide some idea of what transpired during the 20 Year Bond era. It was probably easier to pull a rabbit out of a hat.
Today the roofer provides the owner with a 2 year guarantee covering the membrane only and only the membrane. Should the roof develop a leak in the membrane, in the first 2 years the roofer would fix it. If the roof shows signs of blistering, ridging, shrinkage or failure to stay in place it is not covered. This is what you will read in the majority of the guarantees.
Since approximately 1995, manufacturers as well as suppliers have again started to advertise guarantees. There are generally 5 and 10 year guarantees available all using slightly different wording. There are system guarantees and warrantees, watertight guarantees, gold seal guarantees and the names keep popping up with increasing regularity. The most amusing is the manufacturer that has no plant and offers a systems warrantee on a combination of products over which this manufacturer has no control. What does the roofer provide? Well, 2 years. The roofer knows where to draw the line.
Manufacturers are providing the 5 year and 10 year guarantees basically because their competition is providing these guarantees and specifiers of course want all they can get for their client. Why not provide the owner with a 5 or 10 year guarantee or even a Bond. How do the new guarantees differ from the old Bonded Roof era? There is very little difference but it sure sounds good.
Often, the roofer is caught in a tight spot as a result of an error or omission and the first thing that is usually offered is an extended guarantee. Why does the roofer do this? Economically, the roofer is prepared to take a chance that the roof will outlast the guarantee but it's the owner that assumes the risk. The owner is the one that must deal with the consequential damages to contents, décor and business disruption.
The best guarantee usually results from a good design, a combination of proven products with a good history, an experienced roofing contractor, and good supervision.
Should an owner wish to depend on one of these new guarantees, we suggest the owner's legal counsel review it and provide an interpretation.