Un-nailed mortised floor joists about to drop?
I have a circa 1900 house built on 8”x 8” rim joists, and one of these has bowed outwards. The 2”x8” notched joists were never nailed into the mortises, and those nearest the “apex” of the bowed section appear to be bearing on perhaps just 1/8”-1/4” of the notched end, and are at risk for dropping into the basement below. There is no sill plate, just the 8″x8″ rim band with mortised notches, which carries the 2”x8” floor joists. I need advice on what a good (and low cost?) solution to the problem would be.
Should I simply assume that the rim joist is permanently bowed and go about sistering joists at the “new” length(s)? How would I go about securing the ends to the rim joists? (Using joist hangers is difficult since the original 2x8s are closer to 2″ than 1 1/2″, and are also just 1/16″ above the stone foundation wall which extends into the basement..) Or, should I attempt to pull the rim joist back to its former configuration, and if so what is the best method for this? (I’ve considered threaded steel rods or steel cable with a come-along, but haven’t found a resource describing either technique.)
For the moment, to prevent the joists from dropping, I’ve installed a short carrying beam in the basement under the affected joists, supported by a pair of posts. To prevent (or at least retard) further outward creep of I’ve also installed two lengths of aircraft cable running between pairs of large eye screws with turnbuckles at the centers, and have tightened as hard as I could.
The bowed end is at the “front” of the house, under one of the roof peaks rather than one of the side walls. The house is pretty small: the overall dimension of the affected floor area is about 11’x12’. The 2-8 joists are about 11’ long and run between the rim joist and an 8”x8” carrying beam spanning the middle of the house. The joists are pulled out of the mortised notches there as well, but to a much lesser degree.
The rim joists (and the mortised ends of the joists) are quite difficult to access from the basement. This is a “Michigan basement”: the rim joists are supported by a stone-and-rubble foundation wall which is about 16”-18” thick and 18” tall, which in turn sits atop a sloped wall of dirt parged with concrete. At the affected end, the stone-and-rubble wall appears to have been moving outwards with the rim joist, to the degree that there is a 2″ gap at one of the inside corners. This is not visible outside probably only because it has been patched at some point. I’ve already stabilized some water issues at the exterior, and will need to also undertake some foundation repair. However, what I do depends on whether the rim joist gets pulled back into position or not.
Replies
You've pretty much got it.
I have done quite a few 200 year old homes in my career. There are no books or manuals. You have to get creative. Progress is slow and have patience...if it goes quickly great, but don't rush it....remember you have plumbing pipes so know where your shut offs are....make reference marks using masking tape or marker, so you can measure your progress.
I have used what you describe...come alongs, eye bolts. There's nothing pretty about it. With the tight space, it makes it scary. Been there. Short of making a hole through the first floor so the work could be viewed & executed from above rather then below, you may want to look at an electric boat/car winch, lag bolted to one rim joist & through eye bolt & washer to the other rim joist. It can be controlled at slow speeds, can have plenty of pull and they usually come with a 15' control buttons to keep you above or outside....rather then under the floor. My inclination is that you want to pull the two rim joists together, and not just one of them.
Another thought is to get the weight off the rim joist, and then use the come along and/or winch or whatever you are using to pull it back into a somewhat straight line. what I have done in the past is to lag bolt a doubled up 2 x 8 to the studs of the first floor on the outside of the house. Then jack it 1/2" up and set some braces. This is similar to installing posts on an exterior porch. Just raise it enough to get some of the weight off the rim. Then try and pull it back into place. This can get a little hairy especially since you are on a rock & rubble foundation. If you start pulling, and the wall begins to crumble....stop. (hopefully that's obvious to you.)
Because you are on an aggregate foundation of rock and rubble, your least intrusive and simplest solution is to stop the rim from expanding further, (tie wires & turnbuckles as you've done) and re-support with new piers. Don't add new wood (joists) if you can't support it on the foundation, you're just adding weight.
Another solution/ possiblity might be to attack it from the outside. If you bolted a steel 90 degree angle bracket through the 2x8 joist. You could use a threaded rod through your 8 x 8 rim joist, and try and pull the joists/rim back into position. As I mentioned, you've got to get creative. Work both sides of the house, and multiple joists at a time... and monitor progress...don't rush.
Finally, at a good lumber yard, they should be able to order you simpson(joist) hangers for nominal lumber...(or close to it) They never truly fit & require beating them into position. Try on line and look for companies/lumber yards in the North east, that's where most 200 year old homes are that used nominal lumber. Bostitch makes a pneumatic palm nailer to nail in tight spaces. (small one I just bought was $35) it's made exactly for nailing hangers, or consider removing the baseboard and sheetrock/plaster behind it, and lag bolt through...you could also go at it from the outside with lag bolts.
These solutions are NOT code, they are reality of how to stop the madness without lifting the entire house & pouring a new foundation, and spending huge sums of $.
Good luck. Matt
Why beat them?
It's easy to buy full 2" size for rough cut lumber, or sized for LVLs at 1-3/4"
What you're saying is that they're in the Simpson catalog. Which is as close to seeing them I'll ever get.
Pispoor suppliers, eh?
I can walk into any of three yards that I know of and walk out with them.
Any special item in the catalouge can be here in 2-3 days by UPS.
And all that works far better than mangling a good product to death.
And looks kinda sorta professional to boot!
I can walk into any of three yards that I know of and walk out with them.
And they don't catch you? ;)
retighten those turnbuckles erevry two weeks