This advice applies to any bathroom renovation, and indeed kitchens as well. We’re not talking about the ventilation of the air in the bathroom itself. We mean the ventilation of the various plumbing drain lines in your home. Often, vent lines are impacted during kitchen and bathroom remodelling and it’s good to know in advance if they will, so you’re not surprised with an added expense during or after your remodel.  

What Your Home’s Vent Lines Do

Plumbing Vent lines equalize the pressure across the entire plumbing system so that water can move freely through the lines. Think of what happens when you pour liquid from a container that has only a small opening for the liquid to flow through. It doesn’t flow freely, or quickly unless there is a second hole for air to enter the container. The pipes in your home are subject to the same principle. Plumbing vent lines typically go from the basement, all the way up to the top floor and through the roof. Every drain pipe in the house should be connected to the vent line for things to work well. Each fixture connected to a drain also has a curved pipe – called a P-trap – between the fixture and the drain. Water trapped in the P-trap prevents air and stink drain odours from being released into the house. 

Improper Ventilation

Inefficient vent lines or clogged vent lines can result in problems with drain flow, backups and stinky smells. If the ventilation stack isn’t functioning properly, p-traps can dry out or not fill with water. You may hear signs of improper ventilation – sounds like the sink gurgling when you flush the toilet, or the toilet struggling to refill. Water may even back up through certain drains when a high volume of water rushed through (like when the bathtub empties or the toilet flushes.  

How Renovations Can Change The Ventilation Situation

Doing a major renovation on your bathroom, one in which fixtures such as the toilet, bathtub or shower are to be moved can change the dynamics of your plumbing ventilation. Even smaller jobs like adding a new sink can cause pressure and suction changes that negatively affect the whole vent line. In extreme cases, an additional vent line may need to be installed. Finding out in the middle of a renovation project that modifications to the vent lines need to be made can be a shock. But it’s much worse to find out after your renovation is complete.  If you are planning a major bathroom renovation, get the help of a plumber or bathroom design expert with experience who can advise on what work may need to be done to keep the ventilation working and the pipes flowing freely.