| Author |
Cottage supports are shifting and heaving
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| Frank D 2006-08-23, 9:25 pm |
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I currently have a 30 yr old seasonal two story log cottage sitting on cedar
posts which are either sitting on bedrock about 2 feet below ground or
buried in
soft ground at varying depths according to slope of bedrock. I do not have
access to heavy equipment as I am secluded. The land slope is about 10
percent. My problem is that the frost has been heaving the posts at the rear
of the cottage which is now 5 inches higher than the front. I tried putting
in cement blocks filled with concrete and putting them as deep
as I could but they are heaving too. The construction is simple 6 inch
cedar logs nailed vertically on post and beams. The 2 story cottage
measures 25 X 32 feet. The slope of the bedrock( which is a few feet below
ground level at some support points) can be at 30-40 percent. My next plan
is to just get the cottage level and use new cedar posts. I need to lift the
sagging sections and put in new cedar posts. For this I want to use three
20ton bottle jacks to straighten the main beams which are double 2 X 12.
My problem is how to safely support the jacks at a three foot hight. The
ground is sandy with clay underneath. Can I just use cottage pads on the
ground and put solid concrete blocks to fill the gap. So one support would
be a 18 X 18 X 3 inch reinforced pad on the ground with maybe crushed stone
to level. then several 3 x 6 x 8 solid concrete blocks stacked together and
finaly the bottle jack and a 3/8 steel plate secured to the jack and the
beam. In my area there is available either a 20 X 20 X 4 inch 7000lb per
square inch cottage pad or a 18 X 18 X 3 inch steel reinforced. I would
prefer the reinforced one because its only 75 lbs and easier to stack and
move around. I don't know what the load capacity of the 3 in is and I dont
know how much of a load I will actually be putting on it. There are so many
variables. I've seen house movers using what looks like railway ties to
build cribs to do this but i can't find any DIY info on this method. Has
anyone had similar challenges that can give me some pointers. How far
apart to place the jacks? How to keep the whole lifting assembly dead level
while it is being pushed into the ground?
Sorry for the long post but I'm trying to do this job right for once and not
kill myself in the process. I heard that if the jack is not dead level it
could slip out and....well my wife would be rich ;-)
Frank
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Frank D wrote:
> <snippage>
>
> Sorry for the long post but I'm trying to do this job right for once and not
> kill myself in the process. I heard that if the jack is not dead level it
> could slip out and....well my wife would be rich ;-)
>
>
> Frank
There's only one thing you need to safely complete a job like this -
experience.
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| LightsAREon 2006-08-25, 3:25 am |
| Frank D wrote:
> I currently have a 30 yr old seasonal two story log cottage sitting on cedar
> posts which are either sitting on bedrock about 2 feet below ground or
> buried in
> soft ground at varying depths according to slope of bedrock. I do not have
> access to heavy equipment as I am secluded. The land slope is about 10
> percent. My problem is that the frost has been heaving the posts at the rear
> of the cottage which is now 5 inches higher than the front. I tried putting
> in cement blocks filled with concrete and putting them as deep
> as I could but they are heaving too. The construction is simple 6 inch
> cedar logs nailed vertically on post and beams. The 2 story cottage
> measures 25 X 32 feet. The slope of the bedrock( which is a few feet below
> ground level at some support points) can be at 30-40 percent. My next plan
> is to just get the cottage level and use new cedar posts. I need to lift the
> sagging sections and put in new cedar posts. For this I want to use three
> 20ton bottle jacks to straighten the main beams which are double 2 X 12.
>
> My problem is how to safely support the jacks at a three foot hight. The
> ground is sandy with clay underneath. Can I just use cottage pads on the
> ground and put solid concrete blocks to fill the gap. So one support would
> be a 18 X 18 X 3 inch reinforced pad on the ground with maybe crushed stone
> to level. then several 3 x 6 x 8 solid concrete blocks stacked together and
> finaly the bottle jack and a 3/8 steel plate secured to the jack and the
> beam. In my area there is available either a 20 X 20 X 4 inch 7000lb per
> square inch cottage pad or a 18 X 18 X 3 inch steel reinforced. I would
> prefer the reinforced one because its only 75 lbs and easier to stack and
> move around. I don't know what the load capacity of the 3 in is and I dont
> know how much of a load I will actually be putting on it. There are so many
> variables. I've seen house movers using what looks like railway ties to
> build cribs to do this but i can't find any DIY info on this method. Has
> anyone had similar challenges that can give me some pointers. How far
> apart to place the jacks? How to keep the whole lifting assembly dead level
> while it is being pushed into the ground?
>
> Sorry for the long post but I'm trying to do this job right for once and not
> kill myself in the process. I heard that if the jack is not dead level it
> could slip out and....well my wife would be rich ;-)
>
>
> Frank
>
>
A couple of moths ago TLC ran a show on the relocation of a historic
train station that was going to be made into a museum. They had some of
the most rotten soil you could imagine and the whole station sat
directly on its floor. Picture a concrete matte foundation without the
concrete. They had a lot of details on exactly the method you were
talking about.
Another possibility is contacting a house moving company and talking to
one of their field superintendents.
The cottage pads should be sufficient but since the soil is sandy on
top. I would try to spread the weight by putting several tightly packed
2x12's under the cottage pad. This should prevent most of the sinking.
The jacks do need to be level but at least one will always be out of
level as the cottage is being raised. Get several (borrow from friends
or rent them) 4' framing levels and strap them to the house at the
corners and midspans. You can even get post levels (very cheap) that
tack on to the corners of fence posts and put them on the bottom corners
of the house.
Just some thoughts.
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| bowgus 2006-08-25, 9:25 am |
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> percent. My problem is that the frost has been heaving the posts at the rear
> of the cottage which is now 5 inches higher than the front.
Maybe lower the back by say an inch or so at a time by supporting
beside each post, cut an inch off, then lower ... and repeat. Better
still, replace the posts while at it. A buddy has a similar situation
.... footings don't go down below the frostline so levelling once in a
while is required. Too bad you can't get down to bedrock and put an end
to it.
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| Italian 2006-08-25, 5:25 pm |
| I would suggest forgetting about the old posts and footings for now.
Pour new ones next to the old ones at proper depth (dig with 2 man
auger, very portable) after these have been in place say for 2 weeks
place the jacks on these new pads and re-level the entire building its
not that big. Any other way is going to allow the problem to continue
if you do not get below the frost line you will have heaving there are
no if ands or buts about it.
> My problem is how to safely support the jacks at a three foot hight.
If you do one at a time you do not have to worry about it going
anywhere.
I've seen house movers using what looks like railway ties to
> build cribs to do this but i can't find any DIY info on this method.
these cribs are used after the house is lifted the house rests n them
while the new foundation or walls are being erected. If Im
understanding correctly your saying there is no stable ground on which
to rest these oncorrect ? which is anoter reason why you must pour new
footings first.
> Sorry for the long post but I'm trying to do this job right for once
there is only one way to do it right and not have to do it again....you
must get below the frost line......
Frank D wrote:
> I currently have a 30 yr old seasonal two story log cottage sitting on cedar
> posts which are either sitting on bedrock about 2 feet below ground or
> buried in
> soft ground at varying depths according to slope of bedrock. I do not have
> access to heavy equipment as I am secluded. The land slope is about 10
> percent. My problem is that the frost has been heaving the posts at the rear
> of the cottage which is now 5 inches higher than the front. I tried putting
> in cement blocks filled with concrete and putting them as deep
> as I could but they are heaving too. The construction is simple 6 inch
> cedar logs nailed vertically on post and beams. The 2 story cottage
> measures 25 X 32 feet. The slope of the bedrock( which is a few feet below
> ground level at some support points) can be at 30-40 percent. My next plan
> is to just get the cottage level and use new cedar posts. I need to lift the
> sagging sections and put in new cedar posts. For this I want to use three
> 20ton bottle jacks to straighten the main beams which are double 2 X 12.
>
> My problem is how to safely support the jacks at a three foot hight. The
> ground is sandy with clay underneath. Can I just use cottage pads on the
> ground and put solid concrete blocks to fill the gap. So one support would
> be a 18 X 18 X 3 inch reinforced pad on the ground with maybe crushed stone
> to level. then several 3 x 6 x 8 solid concrete blocks stacked together and
> finaly the bottle jack and a 3/8 steel plate secured to the jack and the
> beam. In my area there is available either a 20 X 20 X 4 inch 7000lb per
> square inch cottage pad or a 18 X 18 X 3 inch steel reinforced. I would
> prefer the reinforced one because its only 75 lbs and easier to stack and
> move around. I don't know what the load capacity of the 3 in is and I dont
> know how much of a load I will actually be putting on it. There are so many
> variables. I've seen house movers using what looks like railway ties to
> build cribs to do this but i can't find any DIY info on this method. Has
> anyone had similar challenges that can give me some pointers. How far
> apart to place the jacks? How to keep the whole lifting assembly dead level
> while it is being pushed into the ground?
>
> Sorry for the long post but I'm trying to do this job right for once and not
> kill myself in the process. I heard that if the jack is not dead level it
> could slip out and....well my wife would be rich ;-)
>
>
> Frank
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