Tomobe – Jacking Up Posts

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What a whirlwind of a year it has been so far. There’s been an interesting mix of work for which I’m incredibly grateful. This spring I had some cool furniture commissions, followed by teaching in Kentucky at The Year of Mud once again, as well as a separate trip back home to MN to visit family. Interspersed between all those things I’ve also been trying to commit any free time to working on our house whenever possible.

My main focus on the house work so far this year has been dealing with the damaged sill beams on the north side of the house, and along with that fixing the areas where posts have sagged or rotted. That has led to further work on the interior rooms adjoining the north wall of the house, which will ultimately become our bedroom.

I covered the start of this work in a post from last year, but since it’s been a while I’ll repeat things a bit to catch you all up.

Here’s what the north side looked like soon after we moved in last August. The wall with the dark siding went all the way to the sill beam, effectively closing off airflow under the house in that area. The little you could see of the sill beam at this point clearly indicated plenty of rot but it wasn’t fully visible at this point.

So the first order of business was to expose what lay hidden from view by removing the siding.

With the siding down the level of rot and deterioration was much more visible. Below you can see a corner post as well as what was left of the sill beam in that area.

The big question is why did things rot out. Clearly moisture is an issue in this area of the house, and after giving it lots of thought, my guess is that overtime as a result of a lack of airflow due to the wall going all the way to the sill, coupled with a slight incline in the land which likely contributed to moisture building up, the sill beam in this area just slowly rotted away.

So when it comes to repairing this part of the house, dealing with water issues and moisture build-up has been my top priority and I’m approaching it from a few angles:

• by ensuring the gutters and drainage system were clear and free flowing (see this post for more on that)
• installing a french drain system to deal with excess water saturating the area (more on that in a later post)
• opening the lower portion of the wall to promote airflow and help keep the area drier

The first week we moved in, I cleaned the gutters and we also fixed a section of damaged pipe which was causing the gutter system to overflow. So with that taken care of I moved on to some demo to open up the north wall. Below you can see one layer of the earth wall removed exposing the inner wood bracing (nuki) and bamboo lattice. I love this kind of wall system. It’s so nice to be able to work with natural materials. (not to mention how satisfying the texture of mud/straw mix is!)

After a bit more demo I had the walls opened up across the bottom of each wall section, giving much more visibility to the state of the structure.

Zooming in on a few particularly bad spots you can clearly see how bad things had gotten. Not much left of the sill in this area, and at this point the post was essentially standing on the foundation stone instead of the sill beam.

Here’s another unique area showing an old splice joint between two segments of the sill.

Notice the height of the sill be in the photo below, compared to the photo above. Originally they would have been the same! Judging by the few areas where the sill was still somewhat solid I’d say it was originally somewhere around 120mm thick (~4 3/4″), but in certain areas it had rotted down to only 24 mm or so (1″)!

The photo below, taken from inside the house looking out, is another good example of the overall issue at hand. The weight of the building translated through the post is crushing down on the rotting sill beam.

So the rotted sill needed to go and the entire north side of the house was in dire need of re-leveling as a result of how much it had sagged over time. Rather than replace the sill beam with new material I decided to do away with it all together, and in it’s place I simply fit stones below each post at the appropriate height. That meant jacking up each post, removing the rotted sill, and placing stones such that the house once again sat level.

To start with we cut away the sill beam right at each post, essentially leaving a small chunk under each post. From there we moved on to lifting each post, which proved to be the hardest part of this whole process. Had we stripped the house down to it’s bare bones things would have been much easier, and given clear jacking points at each post location. But since we’re doing this renovation while living in the house that’s not exactly an option, and many of the posts lacked a clear and safe jacking location. After talking to a friend, and scouring the internet for any images and hints I could find, I landed on a system of bolt-on blocking to use as a jacking point.

It’s a basic system using very heavy duty bolts and timbers to clamp down on the exposed end of the post, allowing the blocking itself to become the jacking point. It took a few iterations to get this system to work out. Slipping was the biggest challenge. We could effectively clamp down on the post hard enough to crush the grain, so pressure was no issue, but the wood on wood connection wasn’t grippy enough to prevent sliding. I tried a few different things, but ended up using thin rubber sheets between the post and blocking to prevent sliding.

Since the house had sagged so much, leveling needed to be done in stages, working little by little, rather than trying to lift everything all at once. Lots of impromptu temporary blocking was used to support the posts as they were slowly jacked up one by one.

Eventually as the floor level started to come into alignment, I cut and fit more permanent granite blocks.

This whole process was a huge exercise in problem solving, and I definitely moved slowly, dealing with issue as they arose. It’s been a rewarding experience to get rid of the old rotted sill, and have the house standing solid again. But it’s also come with plenty of hard to swallow compromises. For one I entered into this project, hoping to get the house back to “perfectly” level, but for a variety of reasons that’s not likely to happen without a whole lot more time and money. So instead I brought the level up to the point that things are even and consistent.

It’s hard to tell looking at the photo below, but the floor level is much more consistent than it was. Yet another issue that distracts from that is the fact that the house has a pretty decent lean to it, which you can clearly see.

From the outside you can see the lean of the posts as well. It’s not terrible but its definitely noticeable and it bothers the hell out of me. In an upcoming post I’ll share a bit about my attempt to fix the issue, but in the meantime at least the rotted sill is out and the post are standing on solid material once again.

Lots more to share next time…

Thanks for reading.