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Jerry
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# Posted: 24 Feb 2009 10:13
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I'm looking for some advice here. The roof on my 24'x24' cabin is in need of repair. It is sway backed along the ridge and also has low spots along its surface. It's probably about 50 years old and has two layers of shingles on it. I haven't been in the attic yet to evaluate the structure, have just owed it one summer and there were other issues that needed immediate attention. But before repairing the roof, I think I need to improve the foundation. It was originally built on blocks placed right on top of the ground, then additional supports were added as it settled and changed. It's really not too bad considering I'm in northern Minnesota where the frost goes at least four feet deep in winter (and barely leaves the ground in summer!), but my cabin is on a sand ridge and the drainage is excellent, so the the cabin itself is fairly level as is. But I would like to get it off the ground more - its now about 8 to 12 inches - and get it really level while I upgrade the footings. I don't intend to place footings below frost level, but to make them bigger and below top soil would be my goal. So, questions about doing this would be:
Would it be best to get maybe two or four heavy beams under the cabin extending beyond the structure to raise it all at once? I'd probably have to hire this out because of a lack of manpower, big enough jacks, etc., but I'd rather do it myself because of $ I'll need for other work.
Could I try to gradually raise each footing area with floor jacks (2 ton), then improve each footing, and work around the cabin that way? There is a center foundation beam that is slightly higher than the perimeter rim joist so raising the rim joist would bring it closer to overall level.
The cabin is one story. What size jacks would be needed to lift a corner or the whole structure?
What materials and methods would you recommend for footing construction dug down about one foot?
Moving to the roof, and depending on what I find there, I'm wondering if it might be easier and structurally better to tear the old roof off and put trusses up. Either way this is bound to be a big job. I'd like to think that maybe after the foundation is straight I can then get in the attic and somehow massage it back into proper position. But the shingles are due for replacement and there is some rot in the soffits so maybe the trusses are the way to go. There are too many unknowns about the roof as of yet.
All this work and I promised myself I'd fish more this summer. The story of my life. Any and all comments, recommendations, etc will be appreciated. I'll be attaching some photos to future posts as soon as I buy a digital camera. Thanks for any help.
Could I gradually raise each corner
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islandguy
Member
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# Posted: 24 Feb 2009 13:28
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I'm no expert, but I would be cautious just raising each corner, particularly on an older structure, since you may actually be raising just the corners, while the center of the structure just sags. You could raise and shim multiple points and work gradually, but I would be concerned the stresses on the structure could cause problems. It may be more feasable to shim and MAINTAIN an area of your structure at the same level, while you replace older supports with new ones, then move on to the next one.
For the roof, I understand some "hogging" is allowable for some time, so if its not excessive, you may consider adding some support to prevent the condition worsening, then redo the sheathing or just the roofing. I'll look foreward to some pics, and some info on your progress.
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soundandfurycabin
Member
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# Posted: 24 Feb 2009 16:08
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The main concerns with raising just one footing at a time would be cracking the drywall/plaster if there is any and binding windows shut or cracking the glass. But you probably don't have drywall and you can open or remove the windows to be safe. Then jacking up each footing a couple inches should not be a problem.
If the soil is really well-drained then frost heave shouldn't be a problem...you can't have frost heave without water. So you only need to dig down to get past any topsoil to the undisturbed sandy stuff.
An automotive hydraulic jack will do the job. If you have 3 posts under the center beam and 3 under each rim, then each is supporting only 60 sqft of cabin..no more than 4000 lbs or so.
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CabinBuilder
Admin
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# Posted: 25 Feb 2009 10:00
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Regarding cabin foundation:
I think raising the structure and shimming one post at a time using the jack is the way to go, however if you need to raise your cabin more than 2-3 inches I would do it in rounds - do all footings one by one couple of inches or so, then repeat the process again until you get it to the level you want.
Although your current 8-12 inches clearance seems good enough to me.
Opening/removing windows and doors as soundandfurycabin suggested is a good idea too.
Good luck.
Keep us posted.
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Jerry
Member
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# Posted: 25 Feb 2009 11:42
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Thanks for the replies and recommendations. I think I'll use two jacks and two guys, one on each side of the foundation point so it goes up evenly and gives me room to replace the old foundation with a better system. What is there now is a variety of blocks piled with various size lumber, etc as it's been leveled over the years. On corners I'm going to use an I-beam under the corner to form a small triangle with the outside corner and use the jacks under the I-beam to raise it evenly. There are a few reasons I want to raise it - even if it's two inches. One, is to provide better air movement under it. Also I want to be able to get under it for running whatever pipes, cables, etc I might need. Another reason is that I want to build a deck on the front and the way it is I'd need to excavate some dirt to make room for joists and decking. Actually I'd like to have the cabin about a foot higher for the above reasons plus the skunks and other critters avoid it the more open it is, but just getting it level and sound will suffice for now. After the foundation and deck I'll move to repair the cabin roof, then on to doubling the 12' x20' outbuilding with shed roof to make it a 20'x24' with gable roof and make the interior into a sauna, changing room, small bar, and general storage. My ultimate goal is to live at the cabin in a very self reliant manner, while harvesting food from the forest and garden, and fish and wild rice from the lake. Thanks again for the advice and I'll be posting pictures ASAP.
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