Adding Insulation to the Exterior of My House.

This was a lengthy project that involved carefully removing the Aluminum siding off of my house, installing 1inch thick foil faced foam insulation and replacing the Aluminum siding.

I have a small house that originally had a stucco exterior, at sometime probably in the 60's or 70's the then owner had aluminum siding installed. The stucco was strapped with 1 x 2 spruce boards and the aluminum siding with its brown backing material attached to the strapping with aluminum nails.

The siding had to be removed from the top of the wall down since when the siding was installed it is installed from the bottom of the wall up and the siding pieces interlock.

Step 1: Tools Required

I used two step ladders and an extension ladder.

A hammer.

Three pry bars of different lengths.

Cordless drill with drill and screwdriver bits.

A caulking gun.

A china marker or pencil.

A spirit level.

Marker pen (Sharpie)

8 foot long straight edge.

Razor knife.

Tin Snips

A person to help.

Step 2: Materials Required

One inch thick foil faced foam insulation, most of the boards I used were made by Johns Mansville. I measured the perimeter of my house divided that by 4 and had a rough estimate of the number of boards needed.

Several rolls of exterior sealing tape, that's the red stuff you see in the pictures.

1 inch long coated wood screws.

Spray foam, used to fill in corner pieces and gaps where the stucco was missing. Hardware cloth and nails for foam boards were also used if the stucco damage was too large.

Exterior grade silicone and acrylic caulking.

Step 3: Insulating the Exterior of Your House

Removing the siding, installing insulation, taping and reinstalling the siding became a matter of routine. Around the windows there is also aluminum cladding which had to be removed and replaced as well. When each wall section was complete caulking around windows was done and at the corners of the house I used spray foam.

Step 4: Repairing a Hole in the Stucco

There was a couple of large holes or missing chunks of stucco that I repaired as the project went along.

The pictures I've shown here was a hole by my fireplace stone chimney. I would speculate that the persons installing the wood strapping missed the head of the nails a few times, but for this particular repair, repair was needed because of water damage due to the lack of eaves troughs when I had purchased the house. I installed the eaves troughs after I moved in.

I cut a piece of hardware cloth and fastened it to the hole with the foam fastening nails, they're the ones with the orange plastic caps in the picture. I then used the spray foam, a day later I came back and trimmed off the excess foam. Rigid foam then was applied into the remaining space and it taped over.

Step 5: a YouTube Video That I Made When He Project Was Started.

I did the video because at the time I could not find any instructional videos on this kind of project.

I hope you've found this Instructable informative.

Comments

[8chilipeppers]

This is excellent work and info, thank you for sharing it. I googled "can i add insulation to the outside of my house" and found your Instructable. I need to do this for my house.

[john pedersen]

Thank you, I did the video after I couldn't find any info on that kind of project in 2010.

Good Luck on your project.

[jeanniel1]

Wow, what a job, and a good one! My 1910 house sure could use some insulation - but the walls are so thin. Might have to consider what you did by adding it to the exterior. Good for energy conservation.

[Somethingtotallyrandom]

Hi John, Did you consider air movement though the insulation in the stud bays? Local siding contractors in my area push people to add a an exterior foam layer, but I tend to think that they only do that to provide a nice, smooth surface for their siding. My home is balloon-framed. After sealing the tops and bottoms of the stud bays, the house was noticeably warmer. Stopping the air movement in stud bays made a huge difference.

[john pedersen]

Hi ringai, Thanks for the comment, no I didn't consider air movement through the insulation in the stud bays, since this project was only on the outside shell of the house and as I understand it "air movement through the insulation in the stud bays" would only apply to the inside of the house. I may be wrong though. Thanks again!

[Somethingtotallyrandom]

Ah, yes. I see I left out the salient portion, here.

The stud bays are also subject to air infiltration via the exterior wall. It might not apply if your home is newer and sheathed in panel goods (particle board/plywood) it might not apply. However, in older homes that are clad with boards, air infiltration is a serious consideration that's often overlooked. The contractors who add foamboard are often only concerned with getting that nice, flat surface to work with and seldom wrap the underlying wall or seal the tops/bottoms of the foamboard which allows air to pass freely behind the foam and into the wall.

My place was wrapped alright, but the studbays weren't airtight. Since the bays run from the cellar to the attic, they acted more like chimneys than dead-air spaces.

[john pedersen]

OK, I see where you're coming from. My house was built in the mid 1940's and at the time I think they were using "buffalo board" over the wood siding. then hardware cloth nailed to it to support the stucco. (buffalo board was a pressed wood fiber board covered with a thin coat of asphalt). I would think that these layers along with the foil faced insulation and taping would provide an effective air infiltration barrier.

I shall have to investigate the layers of my exterior walls when the weather warms up.

[Somethingtotallyrandom]

That's interesting. I'd never heard of buffalo board. Coincidentally, although I live in NJ, I discovered "Buffalo" brand plasterboard (and USG Sheetrock) on some of the newer interior walls in my house. It was pretty interesting. It had big company logos on it as well as usage instructions. The USG stuff also had instructions and marketing stuff on it. You can see a picture of the USG stuff in my house if you search ebay for:

"1920s-antique-SHEET-ROCK-Sheetrock"

I wish I'd taken a picture of the Buffalo brand plasterboard :-)

I think as long as they hot-tarred the the seams it will probably be tight.

Next year I'm planning to re-insulate most of my exterior walls using foam. Some of them have no insulation and others have a 2" batts. The only places with decent insulation are two rooms added in the 60's.