Damaged Plumbing Vent Boots Are Bad
Plumbing boots can be plastic, metal, or a variation of both Plastic boots are known for getting cracks on the outside of the tubbing. Whereas, metal boots are usually known for breaking at the base.
When these functions occur, the best thing todo is check for rotting, torn material and if the boot is leaking past the base. By examining the boot, you can find other problems, which will help you replace the old one. However, if the nails at the base are still in good shape, replace them with rubber-washers screws instead. Depending on your roof and the customized boot item you may have, the best thing to do is have a knowledgeable contractor come out and examine not only your boot but potential problems with your roofing. Unfortunately, sometimes if one thing starts to fail, so does the other stuff. Not all the time, but it's good to keep up with your roof as it ages and changes through seasons.