Adding Wall Insulation to 1950s House

My house is 1-1/2 stories and was built in 1959. The construction is typical for the time/area and consists of stud framed walls with plank sheathing and no wall insulation. At some point, the previous owner replaced the original wood siding with vinyl siding, but I'm unsure if a house wrap was installed. When I opened one of the exterior walls, I found a large wasp nest with a few active wasps, so I think the likelihood of a house wrap being present is slim.

There are 1/8" to 1/4" horizontal gaps between the sheathing planks and I would like to do something to prevent pest intrusion through those gaps while I have the walls open. I've thought about using a canned spray foam such as Great Stuff, but I also question whether or not that is the best approach. I welcome other ideas for pest control within the walls.

The current construction appears to be:

• Wall paneling
• Drywall
• No moisture barrier
• Uninsulated stud cavity
• Plank sheathing with 1/8" to 1/4" horizontal gaps.
• ~Possibly a felt paper/house wrap, but unlikely
• Vinyl siding

My long-term plan will include new siding and will present an opportunity to address the possible lack of a house wrap, but I'm already working on the interior wall coverings, which means I'm probably 3-4 years out from addressing the siding. I'm curious if that time gap should influence how I approach insulating the walls. I'd also like to know whether or not I should consider installing a 4-6mil moisture barrier across the inside of the wall prior to installing drywall if my future may include a house wrap. I worry that doing so will create a moist environment within the stud cavity.

I've come up with a few plans of attack, but I would love to have the insight of someone with a building science background. Please feel free to provide an alternate plan.

OTHER NOTES: The house is located in a rural wooded area in climate zone 4A, but the next county over is 5A.

Option 1:

• Finished drywall
• Moisture barrier (4-6 Mil)
• Encapsulated fiberglass (no vapor retarder)
• Canned spray foam in plank sheathing cracks or other solution
• -3 to 4 year gap-
• New siding (possibly a Hardie product) with house wrap

Option 2:

• Finished drywall
• No moisture barrier
• Encapsulated fiberglass (no vapor retarder)
• Canned spray foam in plank sheathing cracks or other solution
• -3 to 4 year gap-
• New siding (possibly a Hardie product) with house wrap

Option 3:

• Finished drywall
• Moisture barrier (4-6 Mil)
• Encapsulated fiberglass (no vapor retarder)
• Canned spray foam in plank sheathing cracks or other solution
• -3 to 4 year gap-
• New siding (possibly a Hardie product) without house wrap

Advice is greatly appreciated!

-J

Balloon wall construction?
If so there needs to be fire blocking added at the top and bottom of every stud bay. (most likely way the wasp where getting in, it's also a huge fire hazard, the wall acts like a chimney in a fire.)
Why are you replacing the siding?
Trying to fill all those tiny gaps in the sheathing will be a waste of time and money, the house wrap will take care of any air flow issues from the outside.
Might take a whole 2 min. to unlock a piece of siding to see what's under it now.

The house is not constructed in the balloon style.

The siding will be replaced for two reasons: 1 - the vinyl siding was installed sometime in the 80's and has seen its fair share of neglect and abuse and 2 - the wife says it's ugly and she cooks my dinner.

As I mentioned, the siding project is 3-4 years out, so I'm trying to find a more immediate solution for deterring pests.

I'll pop a piece of siding loose as soon as I have an opportunity.

You will like the Hardie siding; get it pre-painted. You can have insulation blown in between the studs from the interior side. If you are going over the drywall or repairing, it's a simple matter of drilling holes in each stud bay and then covering over each hole. There's a neat trick (can be seen on YouTube) of cutting hole patches from a sheet of wallboard to fit the cutout and have and overlap of paper to adhere to the old wall. Big box stores even sell the insulation and rent out the blower. The blown in insulation has a pest deterrent in it so the spaces in the siding won't matter.

I appreciate your input. The current drywall installation was poorly done, which explains why the previous owners installed paneling over it. As part of the process, I will be taking the walls down to the studs, which will allow for pretty much any insulation method.

I was unaware blown in insulation has a pest deterrent. You learn something every day...

I did a bedroom a few years ago similar to what Your describing...West facing room and it got hot in the summer and cold in winter. I cut the existing Sheetrock out but left about 6-8 inches at the roof. I stuffed each Bay with insulation. It helped a lot with temps and noise.

Thanks for sharing.