I have been looking over a lot of roofs recently. Some look good. Many are good. But there are some roofs that are really putting on an act. They look tight and intact but there are seams splitting everywhere. The biggest problems with aging roofs is that the things that are sticking out of them (vents, chimneys, fans, etc) and they seem to separate away from the things that surround them over the years. Mastic is used a lot on roofs to cover a variety of sins. Smearing black tar or it’s equivalent on vent tubes and appliance penetrations looks good and works for a while. After a few years it cracks and starts to separate from the shingles or tiles that surround it. There are also cracks that form down around the step flashing of chimneys. All of these nearly undetectable separations allow water in. That water damages drywall that forms your ceiling and those brown spots start to appear. That is why we don’t recommend putting patch tar here and there over a roof. It just dries up and cracks, separates and leads to trouble.
Aging roofs are trouble for any homeowner. It costs a lot to replace or fix a roof and many simply want to put it off. Light-weight concrete tile roofs are popular in Arizona and will last for decades. The problem is that the underlayment that lays below those tiles will last no more than 20 years. After a while those cracks and seams start to open up and even though the tiles look great, the water starts to make it’s way down. Keep an eye on your roof and make a point to not put off inevitable work that has to be done.
Aging roofs can be be a problem but they don’t have to be.