Have you ever wondered why every one's roof has pipes sticking through them? You may not have, not every one has plumbing on the brain like me! Look though and you will see these pipes on the roofs. Why are they there? They are plain and simple- vents for your plumbing drainage system.They allow the waste water in your pipes to flow freely.They also allow a continuous vent of the sewer system be it municipal or septic system. If you notice all the drains in your home have a trap- A 'U' or 'P' shaped pipe that holds water in them.These traps keep sewer gases and insects from entering the living space.(Toilets have built in traps as well)
If the vent pipes were not in place or if they are clogged the traps and drainage in the dwelling will fail.This will cause a health hazard. You should not smell sewer gases in the home , if you do please investigate.There are several reasons this may happen, the vent pipes when properly installed and maintained will prevent it. Have you ever held water in a straw by keeping your finger over the top? What happens when you lift your finger off? That's right- the water flows out freely from the bottom! This is how the vent pipes work in your home, learn from the straw!

           J J