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Small Cabin Forum / Cabin Construction / Levelling and Fixing (or replacing) wood beams
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Laine29
Member
# Posted: 31 Aug 2019 21:23
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Hey everyone,

My cabin is ~70ish years old, built with wood beams on cement pads. It has become out of level and the cement pads have sunken in to the point that there is not much clearance between beams and the ground.

It needs to be jacked up along one side and at one corner in particular. A second issue is that the beams need to be replaced or at the very least reinforced. They arent looking so good anymore I'm looking for advice about how this might be best accomplished.

I would have to dig down to get a jack under the beam to lift it up and level it. The problem I see is that to jack it up I basically have to lift up the beam. If I jack the beam to lift the cabin, I wouldn't be able to replace the beam because the jack would be under it.

Any advice? Like a chicken and egg problem and I cant get my mind around it. Thanks!

Scott

Nobadays
Member
# Posted: 1 Sep 2019 12:23
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Though others are likely more experienced, I have faced this problem myself with a similarly sized building. My solution was to borrow 3- 8" x 8" beams that were roughly 8' longer than the present ones... just for lifting purposes. These were pulled under the shed via cable right alongside the existing rotted beams. Being longer I had about 4' sticking out each side to place Jack's for lifting. I was fortunate to know a contractor with several heavy duty screw jacks made for this purpose.

We did have to dig down to place the jacks under the lifting beam, on heavy plywood to keep them from sinking. We slowly started twisting the jacks on both sides until the shed was high enough to block securely in place e so the rotted beams could be removed and replace with the building then lowered onto new concrete pier blocks.

Ideally you would have jacks in the middle of the building as well but in my case this was not possible. May not be in yours.

This is a hard, long and involved project, and can be expensive if you have to buy the lifting beams and rent jacks, but can be done by a confident and competent DIY'er. Exhaust your local resources/friend network to find folks who have what you need.

KinAlberta
Member
# Posted: 1 Sep 2019 17:24 - Edited by: KinAlberta
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Your project sounds similar to my planned fix. I recently bought an electronic water level as a first step.

We’ve leveled several sheds in the past but only fine tuned the level on our cabins. The cabins now need more work so I’m still looking at my options. None of our beams are rotten, just undersized as they’ve provided little resistance to the settlement. Plus they weren’t centred over the concrete pads so in a couple points the cement pads have tilted. (This is really too bad as the weight wasn’t evenly distributed at the bottom of the hole. The whole point of a cement pad is to EVENLY distribute the load. Correcting this complicates our job.)

If any of your beams are rotted keep in mind that the building’s floor is almost certainly spiked down to the beam ( joists, rim joist, sill). That makes it more difficult. If you cut out a portion of a beam remember that any joins need to be over a support pad and then the whole beam strengthened to offset the weakness a slice causes.

If the beams are still in good condition, sistering in reinforcing beams beside existing beams might be less work and would add to the strength of the originals. You might be able to build several new beams slide one under and use it as a temporary lifting beam that will ultimately be used somewhere else. Doing this though is like creating a cantilever with all the weight of the building over the original beam and the lift coming inside. You don’t want floor joists snapping and/or bursting through or bulging the interior’s floor.

Hydraulic toe hacks or jack toes, if you can find them, look like a very useful labour saving tool. (I have not used them.) I’ve had to dig a hole for a jack and that hasn’t worked all that well for me. The jack needs to be out on a much larger and very strong solid base in the hole and that requires a bigger hole. You don’t want the weight of the building to drive the jack through, say a cracked cement sidewalk slab, and it all down.

Laine29
Member
# Posted: 2 Sep 2019 12:10
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Thanks for your advice! Sounds very similar to both of your situations actually.

To do a replacement, I would definitely have to make a temporary beam for jacking as you had mentioned, and then have a second beam ready to go in as a replacement. Part of the concern that I've had from the beginning is jacking the old beam to lift it, so I would definitely need a second temporary beam.

Another idea that I had considered was to paint the existing beam with that anti-riot epoxy/resin to stop and control any further deterioration, and then to sister in a new beam on new pads right beside the current ones. I could quite easily put in new pads next to the old ones and slide a beam in beside the current one. Then I could jack and level off of the new beam and shim under both beams for extra support. Any thoughts?

Thanks again for your feedback!
Scott

KinAlberta
Member
# Posted: 2 Sep 2019 23:32 - Edited by: KinAlberta
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Skim this article and note the discussion of LVL beams.

Flitch beam - Wikipedia
https://en.wikipedia.org/wiki/Flitch_beam


Also here’s a cross-ref. to another thread. Note the 3rd post (mine) on using screw piles:

Cabin raising, lifting, levelling technologies and methods - Small Cabin Forum

http://www.small-cabin.com/forum/2_7628_0.html

Brettny
Member
# Posted: 3 Sep 2019 07:16
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Im not sure i would use an LVL beam outside. While your fixing the bad beams why not raise it up a bit so this dosnt happen again?

ICC
Member
# Posted: 3 Sep 2019 18:51 - Edited by: ICC
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For a manufactured beam you would want a Glulam, specifically rated for outdoor use, not an LVL. LVL's are great for beams that are built into a wall as for a header over a large expanse window or door. They are generally not rated to be weatherproof even though the adhesives used may be waterproof because the many layers of thin veneers are more susceptible to absorbing water and causing delamination.

A glulam is built with 2x lumber whereas an LVL is thin veneers.

We've constructed a few simple hiking bridges for the forest service using a pair of glulam beams as the support beams, some over fifty feet in length. Those were made with a slight arch with the ends anchored to concrete bases on either side of the creek.

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