Insulation Installation

TL;DRWe got a huge discount on fiberglass, and had an air leak sealing product applied to the wood framing.  We installed the insulation two weekends ago with a couple days off work:

61-TheCrew   61-Selfie_01   61-Selfie_02

The most popular options for home insulation are 1) fiberglass, 2) cellulose, and 3) spray foam.  Foam also seals against air leaks (greatest cause of energy loss) and comes in two types – open cell and closed cell.  Open cell matches the thermal resistance of fiberglass around R-3.5.  Closed cell has a whopping thermal resistance of R-6.5.  It has a low expansion rate and also adds structural support and is vapor impermeable. 

I REALLY wanted to super-insulate this home, reducing the size of equipment and energy use to maintain it.  Closed cell spray foam insulation would do it.  However, it’s pricey, and most bankers and builders, ours included, see no benefit (ROI) in exceeding code minimums.  We are an incredibly short-sighted culture.

There’s a hybrid method: spray a thin layer of foam to seal air leaks then fill the rest of the wall cavity with fiberglass or cellulose.  It’s called “Flash and Batt” or “Flash and Fill.”  Open cell foam expands too much, so this is only done with closed cell foam.  As a vapor barrier, Building Science must be considered!  Flash and Fill places a vapor barrier on the exterior side of the wall (appropriate for warmer climates), so in colder climates, the right depth must be provided to avoid condensation within the wall, or hello mold.

61-Fiberglass     OLYMPUS DIGITAL CAMERA     61-SprayFoam

I got pricing to insulate several different ways:
Closed Cell  – $21,900
Flash and Batt  – $12,900
Open Cell  – $12,600
Fiberglass + Installation through Builder  – $6200
Fiberglass @ retail + Self-Installed  – $4200
> Fiberglass with Trade Discount + Self-Installed  – $1,000
> EcoSeal + Firecaulking – $1,600
> Odds and ends TOTAL – $2800

The foams were too costly.  But we still wanted superior air sealing.  There are different versions of air sealing products to be paired with conventional batts and we used Knauf’s EcoSeal.  We purchased insulation at a huge discount through a friend.  Since we found nobody to install a product they didn’t provide (with the huge mark-up), we are also saving on labor costs by DIY.  And learning something too.  Cool.

R-21 High Density Batts w/ Kraft Face – Exterior Walls
R-49 Blown-In Fiberglass – Attic
R-51 Unfaced Batts – Attic where inaccessible
R-15 Unfaced Batts – Basement Walls
R-11 / R-19 Unfaced Batts – Interior Walls/Ceilings for Acoustics
R-38 Unfaced Batts – Garage Ceiling / Living Room Floor & Rim Joists

61-Before Insul_01  61-Before Insul_02  61-Before Insul_03  61-Before Insul_04 EcoSeal
Took pictures of everything before installation to know where things are later on!  The blue stuff is EcoSeal.

Day 1 – 2nd floor exterior walls
Day 2 – 1st floor exterior walls and all interior wall acoustic (with Melissa in the crew)
Day 3 – basement exterior walls, rim joists, garage ceiling and 1/2 the 1st floor ceilings.  Huge thanks to Matt and Josh (Melissa’s brothers) for help!
Day 4 – remaining ceilings, mark studs for final framing changes, make/install vent baffles

61-Insulation_01   61-Insulation_02   61-Insulation_03

I followed up during a couple lunch breaks, insulating the 3rd Bdrm and stair ceiling with spare batts after I realized the pain it would be to access, even for blowing in insulation.  Overall, insulating is not rocket surgery, it just takes time.  And when your glasses fog up from wearing a face mask, it doesn’t evaporate in below freezing weather.  GrRr.

61-VentBaffle_01      61-VentBaffle_02      61-Insulation_04


4 thoughts on “Insulation Installation

  1. I’ve been following your project for a while and I’m incredibly eager to see the finished product. As an architect I’m a big fan of the hybrid method of insulating a building. There is seldom one silver bullet that gets the job done for every application. It’s much better to use multiple methods to achieve the desired result and also, as you’ve discovered, save some cost as well.

    I am curious about the basement though. You mentioned that you used unfazed batts for the basement walls. Was there a reason not to go with rigid insulation to a) save on depth of framing required and b) avoid consequences of vapor intrusion through the concrete wall and into the batts? Is the basement wall completely water proofed at the exterior and under slab? If so, what product did you go with?

    Thanks and keep the posts coming!

    • The basement walls are water proofed, but not the slab. I don’t know the particular product, but it’s the conventional black rolled-on glop. Technically speaking. The builder advised unfaced at this location, saying he usually uses it there, but I don’t have it on record. I AM a little nervous about it and will follow up with him this week. Thanks for the comment!

      • At a minimum the slab should have had a vapor barrier underneath. It’s usually 10 mil visqueen (plastic sheeting) over gravel drainage bed over compacted fill. I like to call out 2″ of rigid insulation under the slab if the basement is going to be finished. If it’s just a utilitarian space, no big deal. I would say you’re probably ok as long as there is a vapor barrier and good drainage. It’s when water hangs out that you have issues.
        Thanks. Looking forward to more posts.

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