Air Seal your attic before insulating

When one pops there head into the attic they may see something similar to the first picture & think that hey, I need some more insulation. I have lost count of how many people have simply seen something on TV or had an "energy audit" done where they recommended more insulation & I get called in later as they are still uncomfortable or having issues.
While I agree that the attic below definitely needs more insulation, there were a few things that need to be dealt with first. You see in order for insulation to work optimally it needs to be enclosed on all six sides which needless to say, doesn't fly when it comes to an attic. That is one reason why the R-Values are nearly doubled or tripled in the attic area when compared to walls. So what happens when you add air-leakage underneath – well it really cuts down on its performance.
While we had to remove the insulation in this area of the house,that is not always the case. If you don't have issues with mice, etc... you can simply move it out of the way & fix the problem areas. Some of the most common spots are;
· Wire & plumbing penetrations – use appropriate foam or caulk
· Drywall edges – foam or caulk
· Chases & soffits – foam board, drywall, or plywood to cap
· Around electrical boxes & exhaust fans - foam or caulk
· Stoves & furnace vents – this is a big "it depends" & sometimes is best left to a professional (especially for fireplaces), but fire rated caulk / foam & Roxul are commonly used
· Recessed lights – is it IC rated or Non-IC rated (
Is that the end... no as this attic had 2 bathroom vents that simply dumped their moisture in the attic, baffles that were non-existent and a few other items. Alas those are special issues that easily take up a full piece themselves.
This post is a modified version of you are considering or having this work done we encourage you to check out the full article & the rest of the series.
Shoot, this doesn't look too bad... let's just spray some more cellulose in there & well be good, right? Well maybe not so fast
Eek, guess we might have a few other things to fix & so glad I put that respirator on (If you do have mouse or other droppings, the old insulation needs to be removed)
Guess what happens if you pay someone to add more insulation & they come across an area like this
Ahhh the sins one can hide under insulation
Three guesses where the mice were coming up... in order to close these areas up you can use plywood, drywall or foam board – in this case we were redoing the bathrooms & eliminated the chase all together
Ready to go – fans now vented outside, all air leakage paths foamed or caulked & electrical junction boxes flagged in case one needs to find them later
Frequently asked questions
Have a question about this project?
  1 question
  • Bob Sloan Bob Sloan on Feb 06, 2019

    we lie in a mobile home. during the last cold storm it was cold and we dripped the water to keep from freezing do you have a plan for winterizing a mobile home

Join the conversation
2 of 9 comments
  • John White John White on Jun 04, 2018

    This article is really helpful for those who wondering about the insulation to increase the effectiveness of their home insulation. Proper attic insulation and restoration will seal the gaps or cracks that might permit moisture heat, pest to enter your attic, In addition of that it also helps you to reduces energy expenses during chilling summer season by producing cool temperature inside home and resisting heat transfer from warm air outside. You should try to contact HVAC maintenance provider near you.

  • Jody Burr Jody Burr on Feb 09, 2019

    Hey, Thanks for the information..