It took a couple months to get the concrete steps removed from my house. Now that they are finally gone, I can concentrate on the exterior of the home.
The first step is to fix the rim joist at the front door. Approximately 7 feet of the joist was completely rotted and full of carpenter ants.
After repairing the rim joist, I air sealed the area using Henry Air-Bloc LF, a fluid applied, caulk like product used to seal gaps and cracks. I then replaced the sheeting using 3/4-inch plywood. With the repair work completed, I could then move on to replacing the 1952 tar paper with a modern water resistive barrier (WRB).
One of the problems with old homes are they are sheeting using individual boards with lots of gaps and cracks leading to the interior of the home. The original tar paper kept most of the outside rainwater from moving into the home, but it did little to keep air from moving through the home. The blower door test of my home came in at 12.34 air changes per hour at 50 Pascals, 4 times what would be allowed for a new home. That high of a blower door test is the equivalent of approximately 1 air change per hour naturally, meaning the entire volume of air inside the home is exchanged with outside air once every hour. The home tends to be a little uncomfortable during both the summer and winter.
My intent is to seal as many pathways between the exterior and interior as possible. Regular house wraps and WRB’s work, but not as well at stopping air as I would like. I chose a product called Henry Blueskin VP100. This is a self-adhered membrane, a peal and stick product much like an ice and water roof membrane. Blueskin has a perm rating of 33, a good number for a WRB. Read more about perm ratings here.
I first installed a 12-inch band of Henry Blueskin at the bottom of the sheeting, covering the bottom of the shiplap and attaching to the concrete foundation. I was a little skeptical whether the Blueskin would adhere correctly to the concrete, so I used an aerosol primer called Henry Blueskin Prep. It seemed to improve the bond.
The next step is to install the vertical 48-inch pieces of Blueskin. I chose to run vertically because I am working solo and found it easier to install this very stick membrane up and down. It’s also important to roll the Blueskin using a J-roller to get all the air bubbles out and activate the glue adhesive, which bonds better using pressure.
Another detail I am incorporating into the exterior is a vented rain screen, which you can read more about here. The rain screen detail includes a 2″ x 3/8″ furring strip stapled over the Blueskin at the location of each 2x stud. (This will help locate where to nail the siding). There is also a bug screen at the top and bottom of the rain screen to prevent insects and other critters from entering the space.
Next up, the 3′ x 12′-bedroom addition. Stay tuned.