It is currently about 20°F here in Denver with snow in the forecast several days this week. Obviously, we’ve all been inside much more than normal lately with the ongoing Covid-19 pandemic, but this weather means no garden or workshop time today. With that being the case, I decided it’s appropriate to discuss a recent indoor project that Allyson and I completed.
Our house was built in the 1950s. Because of the age of our house, it did not include a bathroom vent fan when we moved in. Typically, older homes weren’t sealed very well (we can attest to that), which meant that moisture inside the home dried out without many mold issues. Modern homes are sealed much better, which dramatically improves their insulation, but can cause problems with moisture inside the house. That is why almost all homes built in the last 20 years include bathroom vent fans that exhaust to the exterior of the house.
Currently, our home does not have any issues with moisture inside as it is poorly insulated and sealed. I am hopeful that that won’t always be the case, as we have plans to add insulation to all of our exterior walls (where there is currently none). Once we end up adding insulation and sealing all of the air leaks that we possibly can, it is feasible that our bathroom could have moisture issues if we didn’t add an exhaust fan. Plus, an exhaust fan has other uses involving smells if you get my drift.
In January I started to install a new chandelier in the bathroom to highlight the vaulted ceiling and replace the terrible over-the-mirror lights we used to have. Like any good project, this expanded into wiring a new lighting circuit for half of our house, installing a new hallway light, new bedroom and office overhead fans, and installing a new bathroom vent fan. I’ll cover all of those projects in more detail in the future, but today I am focusing on the bathroom vent fan.
The fan has to vent to the outside of the house. Originally, we planned on venting straight up from the bathroom, out of our roof since we don’t have an attic and that would be the quickest path to outside. The problem is that our roof is rolled roofing, meaning fixing penetrations through it typically involves more skill and torch work than I am currently comfortable doing. After researching how to put a new penetration through rolled roofing for several days, I had the idea of running the exhaust vent out of our roof soffit. This solution meant no roof penetrations, but it also meant running about ten feet of flexible tubing through our roof joists to the soffit without having an attic for access.
To begin, I ran wiring to both the new chandelier location and the new fan location, and Allyson cut holes in the drywall for both. We didn’t put these on the same switch, but they both are controlled by a switch in the same box, so it made sense to run the wiring at the same time.
After getting the wiring run and the hole in the drywall, I needed to run the flexible tubing before installing the fan housing. Luckily, the insulation in a roof with no attic includes a couple inches of venting space for moisture control. I was able to use some of this excess space to push aside insulation and run the tubing. From the vent location inside, I used two electric wiring push sticks to run the length of the joist and get to the vent location in the soffit. From the outside of the house, I removed the soffit for access. I then pulled the push sticks all the way through, attaching the tubing to them in order to pull it the full run without cutting more holes in our drywall.
Once I had the flexible tubing installed it was a simple process to install the fan and wire it up on the inside. On the outside of the house, I cut a four inch hole in the soffit. I then connected the tubing to a low profile soffit vent fan that we ordered online.
It was a few days of work to get everything installed, with the hardest parts being running the vent tubing and running a new electrical circuit. The new circuit wasn’t required for the fan alone, but I decided to upgrade half of the house’s wiring at the same time. We still have a lot of drywall patching to complete, from this install and the chandelier, hallway light, and overhead fans that I’ll cover in the future. In the meantime, we’re finally able to take a shower without the mirror completely fogging over, and that is priceless.