Help me jack my shed...

[fin29]

Specs: apx. 14x24', rotten sill on one long side, good sill on the other, no sills on the front or back (just joists). It's probably 80 years old. It's supported on the four corners plus the middle on the two long sides by loose stone/concrete block piers, not mortared.

Problem: with all the rain, the side with the good sill is now laying on the ground toward the front of the building. The part with the rotten sill is about 8" up into the air. Usually, it's sitting about 3" off the ground on all sides.

I would like to be able to jack it up, replace the rotten sill, pour 4-6 concrete footings in the ground, and drop it back down. How do I do it? Jack first? Pour footings to jack from? How do I jack the side with the rotten sill? Etc.?

Here's the front of the shed--the good sill is on the left and the rotten one on the right:


This is the pier on the right front:


Right side back, up in the air, siding popped:


Left back, good sill side, almost on the ground, siding popped:


Middle left side, almost normal looking:


Left side from middle pier to front corner, which is literally on the ground:

[Hammer4]

I found this as an example:

http://www.hgtv.com/hgtv/remodeling/...924142,00.html

You most likely would have to dig a few small pits to get some timbers in place under the house running the width of the shed, then have room under them to put a house jack and blocking to get the shed picked up and level, then dig under neath and put your foundation in place.

For a shed, I would most likely use the concrete support blocks similar to they show in that link and just let the whole structure float on top of the ground.

Since it is free standing and doesn't have any plumbing to protect ( I assume ) then having it move a bit if the ground freezes and expands shouldn't hurt it as the whole structure will be floating on top of it.

[Alex]

Get a house jack, or you can try a "Jackall", or a small hydraulic jack. Just do it. Move slow and take your time. Try to jack up one side, then the other, adding beams or jack boards underneath only if required. Jack a little, then block up, etc.

Get it up high enough to work on and inspect the underside. Replace as required. Set back down on what ever type of footing or foundation you want. Depending on your concern about earthquake in your area, you could even use flat rocks or concrete blocks. Or you could build the most expensive type of structure -- a poured below grade basement.

It is not that difficult to move or lift. If you have time to watch a professional (or hire one for half a day), you will see how they jack a little at a time, but they keep at it steady, until they get the structure they are moving where they want.

Good luck, have fun,

Alex

Hopefuly, it is NOT full of lots of stuff that's too heavy. It's a good idea to make it light as possible.

[fin29]

Nah, it's full of antique tools and banana boxes. It's a gem of a building, though, and I hate to lose it.

For the footings, what about sonotubes? Do I have to go below the frost line for those? I thought we could drop them into holes, fill with concrete, then use those pyramid-shaped concrete blocks against the sill.

I'm in central Maine...

[mpillow]

We used the big poured concrete (circle) blocks(called round pads?) when we jacked our camp... round pads on the ground...stacked blocks(concrete w/ 2 holes and flats) with pressure treated shims.

We made "floating beams" because the joists were all good...they were rough cut hemlock 2 by 8's (12ft long ??) spliced 3- 4 board thickness over a 20ft span...
Front sill was replaced due to rot as well

We used a combo of bottle jacks and railroad jacks....those round concrete pads with pressure treated "shims" ...surplus round pads or flat square blocks to set jacks on on either side of beam location.....I think the beams are every 8 ft?
The camp was 16 wide by 24 long when it was first jacked...10 years ago!
We also used the string levels...

[arbutus]

Sonotube would work fine. In Maine, I would at least 2 feet deep. Make the top of the sonotubes level, fill with concrete to the top, then lower the shed right on top of the cured concrete. Consider placing anchor bolts in the concrete and tieing the new sill plate to them.

I had to replace the sill plate on a corner of my house!!

[michiganfarmer]

I did it with my house while we were living in it. Half of our house was on a crawl space. I got in the crawl space on my hands and knees and started digging with a shovel. I dug it out to 7 feet deep. Then I poured 3 concrete pads, and put support posts on the pads to support the house. Then I dug the dirt out from under the old footers, cut the footers, and block loose from the bottom plate of the walls, then poured new footers, and laid new 7 foot concrete block walls back up to the wood house walls. I jacked the house up an inch to get the last course of block in, then set the house back down in it.

[Alex]

It's a fancy shed. Still I don't think you need anything more than some flat rocks or concrete blocks, if earthquake is not a problem.

Sono tubes are fine. But are they over kill? The digging or drilling is a bit of a problem -- not really if you NEED to do it. To find out call a local structural engineer -- explain it's a shed -- they might just tell you what will work. Or, hire a geo-technical engineer, and a structural engineer and get a proper answer.

But our 28 x 20 two story log cabin has been sitting on big flat rocks stacked on top of one another for 34 years. The rocks are 12" to 18" above the surrounding grade, based on land slope. Our cabin is in northern BC -- 40 F below, but NO earthquake danger, or very low.

We have had NO movement, and no frost heaving in 34 years.

However, each situation is different.

But, it is a shed right? A very nice shed.

Good luck,

Alex

[Qwispea]

Originally Posted by michiganfarmer

I did it with my house while we were living in it. Half of our house was on a crawl space. I got in the crawl space on my hands and knees and started digging with a shovel. I dug it out to 7 feet deep. Then I poured 3 concrete pads, and put support posts on the pads to support the house. Then I dug the dirt out from under the old footers, cut the footers, and block loose from the bottom plate of the walls, then poured new footers, and laid new 7 foot concrete block walls back up to the wood house walls. I jacked the house up an inch to get the last course of block in, then set the house back down in it.

This is interesting..but I'm quite the novice when it comes to building terminology.
Can anyone please explain to me what the following terms mean:

..what is a sill?
..what is a sill plate?
..what are footers?
..what is a concrete pad?
..what are support posts?
..what is a bottom plate?

[comfortablynumb]

if you can,mthere is an even easier way...

do it from inside, by removing part of the floor to place the jacks in better spots.

if its just "a shed" then removal of sections of the flooring shouldnt be a problem, if its plank floor it is even easier.

then with the bottle jacks, inch the whole building up evenly. as you do, you might want to add a few more jacks on more solid sections just for kicks.

this will eliminate the digging and crawling and possibly the building fallng on you while you are under it.

replace the piers with the concrete tube forms.

while it is Up you can put it on skids and drag it elsewhere.

[comfortablynumb]

the tubes, if you cant dig a hole where ya have to, can be a pain. if you can repair the part that sits on the pillar, you could pour block of concrete with a simple square form, as deep as you can dig out, on each corner and under it in places.

[fin29]

Originally Posted by comfortablynumb

if you can,mthere is an even easier way...

do it from inside, by removing part of the floor to place the jacks in better spots.

if its just "a shed" then removal of sections of the flooring shouldnt be a problem, if its plank floor it is even easier.

then with the bottle jacks, inch the whole building up evenly. as you do, you might want to add a few more jacks on more solid sections just for kicks.

this will eliminate the digging and crawling and possibly the building fallng on you while you are under it.

replace the piers with the concrete tube forms.

while it is Up you can put it on skids and drag it elsewhere.

Working from inside is a decent idea, but what do I jack against? If the ground is so soft that the building is heaving, I doubt a jack laid onto the ground to jack against is going to be very effective, or am I missing something?

[Gideon]

I am a housemover by trade from NCarolina. Jacking small blds is often dangrous because you do not respect it-weight wise. It is very much more than enough to crush you. Cut some 4X4s or 4X6s about 3 feet long-two feet will work. Cross stack them as you jack up the building in three equally spaced locations along the long side. If you place a short piece of 6X6 angle iron on top of the jack it will distribute the load and not cut through the bad sill as you raise it. Raise one side slightly and secure it with the three "cribs" of timber. Make sure to have the center of the "crib" halfway outside the building so it will not lean over as you jack the other side. If the rotted sill cannot support the load just rip out a section and temporarily place a 4X6 under the ends of the joists to jack/"crib" on. Once up and safely supported dig down past the frost line and pour a pad or simply place two 4X8X16 solid cement blocks on well leveled and tamped earth then build your pillars. I would place two pads under even the single stacked middle pillars. If freezing is a problem you might pour the holes solid to prevent them from bursting/weakening. If not then place another solid pad on top of the pillars to give a better load distribution/prevent giving the rodents a place to hide in the block cavities. A treated 2X8 cut slightly longer than 16" placed on top of each pier will help keep out termites. I would tell you to pour a little burned oil around the piers but that would not be ecologically sound-sure keeps the wood eaters at bay. To increase the load bearing ability of the floor place a "drop sill"(4X6) the length of the building in the middle and place piers under it also. Will take all the shake out of the floor. The building looks nice. Don't let rotted sills scary you as they are probably the easiest structual member to replace. To answer the question about terminology
Sill--------outer larger timber under the walls(and inside walls also)
Joist------"ribs" that rest on the sills(nailed to them) to hold the flooring.
Pillars-----masonary supports holding up sills
Footings--usually concrete poured for the pillars to sit on.
Hope this has helped-E me if there are specific ?s--be glad to help--just be careful. As I said earlier, small buildings will hurt you and by building good "cribs" the critter will not shift around on you.

[Cabin Fever]

I agree with Alex, a small building like that can simply sit on concrete blocks placed on the ground. You might have to re-level it every other year or so, using wood shims, put that's no big deal. Many small cabins in Minnesota are supported like that and almost never have to be re-leveled. The whole idea is to just get the new sill and floor frame off the ground so air can circulate underneath which keeps it dry and prevents it from rotting.

[boxwoods]

If you get a couple telephone poles or cut a couple logs a little longer than the building. Jack the good side high enough to get log under as far as you can toward center. That way you should be able to get the rotten side off the ground with light jacking. Put the second log under building and using chain you should be able to move whole building enough to do your foundation piers. Replace rotten boards and slide it back on.

[elkhound]

for the lowest side they make a small jack called a power ram...lifts like 80tons..its a low profile jack...use a railroad jack on the higher sides.set the building at least 18 inches off ground to stop wicking of the wood.then try the sona tubes or dig small footer and make some piers.wood is just llike a wick in a kerosene lamp.this should be a easy fix for a nice building like that.you can get the jacks at most rental stores.good luck