This year’s record storms in Northern California proved to be too much for my aging roof. I had managed to stretch a 30 year roof to 34 years due to the mild winter weather the past several years. This year’s torrential rain washed away the granules on the southern exposure and the high winds tore up the roof in many places. With a safety harness, hammer, roofing nails, putty knife, and can of Black Jack, I was able to make repairs to keep the roof from leaking. I then spent the next several weeks researching roofing options, along with getting three quotes, and settled on a white roof. This will not only be period to the house, it will be an Energy Star rated roofing material. A new roof also means it is time to address a roofing structural problem that has been a puzzle since I first discovered the issue.
The roof rafters above the kitchen and back bedroom were never braced to the wall. The wall between the kitchen and bedroom is not a load bearing wall. The load bearing wall stoped at the wall that divides the kitchen from the original dining room. The wall between the kitchen and bedroom is shifted 24 inches off of the foundation. The builder decided not brace the roof. The result after 115 years is a 2 inch bow in the middle of three rafters. I am certain that this is putting a strain on the rest of the roof and braces. So to prepare for the new roof, I have three problems to solve: 1. Add bracing to six rafters; 2. Fix the two inch bow in the rafters to even out the roof surfaces and redistribute the load; 3. Make a non-load bearing wall into a load bearing wall.
I started by looking at what part were available from Simpson Strong-Tie so I could design an adjustable brace. With two blocks, several screws, and some Gorilla Glue, I had a solid joint that wound allow adjustment to remove the bow. Since all the parts are the same dimension, once the adjustment is complete, the brace can be strengthened with a backbone to prevent buckling in an earthquake.
The threaded rod is a 3/4-10 UNC, which means there are 10 threads per 1 inch of length. One complete revolution of the nut is 1/10 of an inch. Since it has taken 115 years for the rafter to sag 2 inches, it will also take some time to take the bow out of the rafter. Every week or two, I will go up into the attic and give the nut a half turn while listening to the structure. It there are no popping sounds, I will give the nut another half turn and wait another week for the rafters to adjust. Then repeat the process until the rafter is inline with a string that is strung along its length. As part of this work, I added a plywood pathway that is screwed down to the ceiling joists. The scrap wood path was very narrow and not very safe. I also feared that the ceiling would become the next project.
Access to both the attic and under the house have been the biggest challenges with this project. The beam and truss above was built to fit through the small entrance to the attic and assembled with glue and screws after being placed in the attic. The crawl space is about 30 inches between the dirt and the bottom of the floor joist, which when compared to my parents house, is quite roomy.
I would need to create several new footings for a new beam to support the floor joists below the wall that was now supporting the new braces. Right after I moved into this old house, I was required to do several seismic retrofit projects (note the structural plywood on the cripple wall). Based on this experience, the new footings would need to be 12 inches square and 12 inches below the surface of the soil. I would end up spending the good part of a day with a seven pound demolition hammer digging the five footings.
My calculations showed that I would need to mix and then move 6.5 cubic feet of concrete under the house.
Each 60 lb. bag of concrete weighs about 65 lb. with water. Turned out to be a good workout mixing and then dragging each tub of mixed concrete under the house.
One bag of concrete fit in my well used plastic container. It would be interesting to know how many feet I have dragged this container under the house. I used it for the seismic project, the plumbing projects, and when I was rewiring the house.
One of my ramps worked well to transition from the outside to under the house. This is also a great picture of the beam that is supported only on one end.
The concrete set for a day and then I removed the forms. I allowed a week so the concrete could cure to half its strength. In thirty days it will cure to the full strength. Saturday I added the beam and posts to complete the work on this phase of the project.
There is one more footing that needs to be added to tie the end of the new beam (right side) with the beam (just barely in the picture on the right side) that is offset by about 12 inches and has only one support. As I was writing this post, I recalled extending the center foundation to the back foundation of the house and adding a section of cripple wall. The back porch use to be open and was supported by a different set of supports and joists than the house. This additional section of cripple wall with plywood tied the center foundation to the outside foundation for shear strength during an earthquake. The support beam with one post is part of the structure for the porch. The extended cripple wall is now also part of this structure, which makes it appear as if this beam was placed in a random location.
I have spent many weekends and evenings working on this project. After bumping my head one too many time, I invested in a confined space safety helmet. Best money I have ever spent. When all of the work was complete, the house and yard looked the same. The picket fence sill needs to be finished. All of the rooms need a fresh coat of paint. Weeds have sprung up when I was not paying attention. Only those who read this post or venture into the attic or under the house will ever see the improvements to maintain this old house.