These photos illustrate the importance of not forgetting to check on the vent stacks and caps on the roof of your home. During a recent home inspection in Aurora Colorado, I inspected this roof and attic. The roofing was in decent condition, but when it had been replaced earlier, the original furnace vent and stack were not replaced. Instead, the owner had applied some type of sealer around the base of the vent. That may have worked for a while, but as you can see, the vent is now leaking into the attic. The stack inside the attic shows the deterioration caused by repeated exposure to water coming in from the base outside. It appeared to be a slow leak which likely had gone unnoticed. Roof leaks like this, can cause significant damage to the roof decking, rafters or trusses, or drywall ceilings. Slow leaks or seepage which occurs over time is hard to detect if the intrusion of water is not enough to penetrate finished surfaces in the home. It is always a good idea to replace all the roof vents, exhaust vents and stacks and vent boots when the roof of your home is replaced, and to check periodically on the condition of the roof and vents to make sure an undetected problem is not occurring in the attic of your home.