This is part 8 of the prep work we did to get everything ready to blow GreenFiber cellulose insulation in our attic. At the bottom of this post we have a link to every post in this series if you want to check out the whole shebang :)
My post titles are getting weird. I blame the excessive amounts of insulation dust.
In addition to adding vent chutes and protecting your heat sources with flashing, another important step in prepping your attic for blowing insulation is sealing up air leaks between the attic and your living space. These leaks occur around any obstruction through your ceiling- recessed lights, AC vents, plumbing, etc. Just taking the short amount of time to seal these up makes a HUGE difference. Even if you’re not planning on upping your insulation anytime soon, take a little time to hop up there and seal things up. Plus, it’s kinda fun. Like piping icing onto a cake! Just don’t eat this cake when you’re done.
We used fireproof expanding foam since we’d be sealing around heat sources like recessed lights as well. It was pretty easy to work with, though my trigger finger did get tired towards the end. Just make sure you don’t overfill any areas where the foam doesn’t have room to expand outward. In the picture above, I’m sealing around our newly fixed guest bathroom exhaust vent.
Then we tackled the 14 recessed lights we had previously added flashing around. We decided to do the foam after the flashing because we didn’t want any foam-gone-astray to get in the way of putting the flashing flush against the floor.
We made sure not to forget things like the kitchen exhaust vent over our cooktop and the lights on either side of it!
We also foamed around every AC vent. I had to work around some of my recently reattached insulation, but it wasn’t too hard.
For pipes and wires, I did what I could. A lot of them were obscured by insulation so I’m sure I missed a few. But every little bit helps! I think they’re probably not AS big of a deal since they usually go down into your walls but not usually through your ceiling. But I’m sure adding a little foam on top doesn’t hurt.
While we were up in the attic all week, we noticed some other air leaks we had to attend to. Big ones. From our AC ducts. All in all our ducts themselves were in good shape, but at spots where they met other ducts at a junction and where they connected to the AC unit itself, things were not looking too hot. Actually they were quite cool. Because cold air was being blasted into our attic, which is basically like us throwing money away on our electricity bills.
We have an AWESOME brand new AC unit and it was a shame that these ducts were making him look bad. Here were our trouble spots. The front of our AC unit:
The back of our AC unit:
And a junction box over the master bathroom area (this picture is from before I re-stapled up all the torn down insulation). You can see that all of these areas had been taped up before, so that should have been a sign.
So we got some heavy duty foil tape made for flexible AC ducts and went to town on em. Note- don’t use duct tape. Ironically, it’s not actually good to use on your AC ducts because it will deteriorate over time.
The interesting thing about air leaks is when you think you’ve closed it up, the leak somehow finds it’s way out another area. Before we knew it, we had taped up literally the entire junction in the picture above.
Same goes for the front and back of the AC unit where the ducts entered the unit itself.
The back side of the unit was a little harder to get to because of the low ceiling, so Evan and I tackled it together. I think Evan is holding the tape roll in his mouth in the picture below, but I like to think that he’s eating the air duct. Or kissing it. Om nom nom!
With the two of us working together, we finished taping off the ducts pretty easily. But there was one other little matter to attend to…
Cold air was SHOOTING out of these PVC pipes!! I wanted to cap off both openings (pictured above), but first I looked up what their purpose was. Turns out they are there so that we can pour bleach down them every so often to clean out our AC drain (both connected to our AC drip pan, one is the main drain and one is the backup trap). Based on our research, it seemed like capping them off wouldn’t hurt, so I strolled the Home Depot PVC aisle and found the right sized caps for the job.
After all our air leaks were in order (both those through our ceiling and those from the AC), we started getting REALLY excited about insulation day!! Just a little last minute prep to do!!
Psst – To see the whole process from start to finish, check out our other posts! You can see our overall plan for blowing insulation, and check out all the prep in Part 1, Part 2, Part 3, Part 4, Part 5, Part 6, Part 7, Part 9, and the actual blowing of insulation. Big project!
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