Learning about this house.
1. The back rim joist is home to a colony of carpenter ants. They thrive in damp wood. They don’t eat it, just make tunnels to live in. They were only interested in the non-treated damp wood parts of the house.
2. Carpenter bees liked the pressure treated deck handrails and had a long system of tunnels there. Half inch smooth round holes.
3. The house exterior is cedar. Cedar claims to be “insect and rot resistant”. That’s like saying plastic sheets are “water resistant”. In all the cedar I looked at, I saw no signs of insect or rot. Not a nibble. Even in the parts that had surface damage from the sun and no longer had a protective stain coating. That is not to say it repels insects. Many kinds of various thing were living just under the cedar. As well as I can tell, this is the original siding that was on the house in 1970. Possibly it was applied during the 1990 remodel. So, it is 30 or 50 years old and still holding up fine. Just a few cracked pieced here and there that need replacement and then a good heavy stain treatment to shield it from the sun. Only two sides of the house get direct sun exposure and you can tell a huge difference in the condition of the remnants of stain between shaded and sunny sides.
4. The tarpaper under the cedar was hung vertically. That’s strange. I would have thought a nice horizontal hanging, would repel water best. As I understand it, tar paper in the heat of the summer melts slightly and bonds to adjacent layers, so it likely didn’t matter either way. In places where I need to expose the tarpaper, I will replace it with modern house-wrap like Tyvek or Lowes Tyvek, or 84 Lumber Tyvek, but not Chinese Tyvek off the internet. It probably contains lead.
5. The back part of the house, over the carport, was evidently a screen porch or a later addition. It is supported by four 8 foot high columns that look like this at the top:
Fascinating and strange design. The column is stacked cinder block coated with stucco paint. The two 2×10 beams you see in the picture are not attached to the columns. There are two 2x6s laying flat on top of the columns that the 2x10s nail onto. The floor joists then lay on top of those 2x10s and the flat tops of the 2x6s. I don’t know much about engineering, other than every single video on YouTube warns me to not do what they are doing without consulting an engineer, but one would think they would use the beneficial combination of gravity plus vertical 2x10s on top of the columns to carry the weight and distribute it downwards. There must never have been a room full of fat people upstairs doing bunny hop line dancing.
I strongly suspect the columns themselves are on top of nothing more substantial a foundation than 4″ unreinforced concrete driveway slab. This accounts for the 1-3/4″ of settling the back of the house has seen.
At least all those visible dimensional lumber are in good and dry condition. Before I put the cedar back on them, I’ll give them a good heavy insect spray, just to keep the bugs honest.