Radiant Barrier



Radiant Barrier in the attic

 So last weekend, I teamed up with one my friends and installed a radiant barrier in both our attics.  It was a fairly easy project.  His attic has gables and a single gable mounted attic fan (no soffits), so we put the radiant barrier directly over the insulation.  In my attic (has soffits and attic fan), I had a contractor install  ridge vent and then I stapled the radiant barrier to the joists except for the small attic space over my bonus room, where I installed the radiant barrier over the insulation.
 
Like I said...it was an easy project.  Luckily, it was cool outside so we didn't kill ourselves, although I did sweat up a storm.  Above the attic duct work (which is high) we "tented" over it to keep the heat away.  I used atticfoil.com for the radiant barrier.  It was a good product and i have no complaints.



Looking at the top of the attic.  You can see my high duct work and the "tent" over the top

 I can't say for sure how well it is doing, although today when I came home after a hot day (sunny and a high of 91F),  I noticed for the first time since I can remember, the attic fans  were not on when I walked upstairs and the temperature was 82F (thermostat set at 84F).  Nearly all summer when I came home the upstairs temp was 84F and the HVAC was cycling.    We'll see after August and September.

Insulation...

OK...so I'm not sure why this came to me now...but I went up to the attic and measured home deep my insulation is.  Well...it's 6" of blown-in insulation.  That means at R2.5/inch, I only have a R15 for my attic.  It's recommended by Energy Star that I have a R25-R38.  In my old place I had a R30.  So, why so little?  And why didn't this tid bit of information show up in my ENERGY AUDIT that was performed last April?  So...maybe I could have used that 30% tax credit (up to $1500) that JUST EXPIRED.  @#$%@#@#%^!!!!

So...(wait for it)...I made myself a spreadsheet to figure out how much insulation I'd need.  It's roughly 980 sf in the main attic area because I have a storage area in the middle that has plywood over it. What's intriguing is that I went on the Lowe's website and I was surprised at how much blow-in insulation costs.  For an extra 7" of blow-in insulation to get to R38, it was going to cost me ~$2800. And that doesn't count the 2x10's I'd need to hold the insulation in place. However...since this insulation will go on top of my existing blown-in insulation, I can use roll-out insulation (it doesn't come with vapor barrier...good!) that is R30 and measures ~32 sf for only $13.50.  So, using this will cost me only ~$450 for 32 rolls and it will get me to R45.  It might be a little "itchier" if I don't bundle up correctly...and I will...I learned my lesson on that a while ago...but I'd say saving ~$2300 is well worth it.

Well...I guess I know what I'm doing this weekend.  And its supposed to be a high in the 30s too...so bundling up won't be a problem.