Rebuilding Foundation and Raising House

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  #1  
Old 07-21-05, 08:48 AM
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Unhappy Rebuilding Foundation and Raising House

We purchased a small beach cottage several years ago. Being first time home buyers we fell into the trap that many do with an owner contract and now have all kinds of structural issues to contend with.

Some basics on the house; the foot print is 22 x 24 foot and it is on post an pier (I think that is the correct terminology) foundation. There is only about 6 inches of crawlspace underneath, though it does have a vapor barrier. There is a wall that runs the length of the house, that I am assuming is load bearing, in the center interior, though, it does have a section that is not continuous to allow for the bedrooms and bathroom entry.

My question is two part:

We need to raise the house, and repair the foundation. What is the best way to go about doing this? We had thought to use jacks to slowly lift the house up the needed 10 inches or so, or partly up and then dig out the crawlspace for the additional room, leaving the areas around the piers intact for the time being.

Secondly, what sort of support do we need to place on the jacks to disperse the lift evenly?

Both my husband and myself are very handy and he has done remodeling work in the past. We got estimates several years ago from 3 contractors and all basically said the work was going to be more than the house was worth. Since we have no choice, and must keep the house, (long story) we need to begin doing repairs ourselves, and only hire out the things we cannot do on our own.

Any help, suggestions or ideas would be greatly appreciated.

RhainyC
 
  #2  
Old 07-21-05, 07:44 PM
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Lift House

I wish that I had a nice and easy answer for you. I have done several new foundations in your area years ago. There is not much of a chance for you to jack up the home. Your best bet, is to get ahold of a house mover, and have him lift your house. Leave it up while you redo your foundation. He will charge you for beam rental. Most will not leave them up for more then 30 days. This is what I would do. I do this all the time. House movers do not mind. Just some thoughts. Good Luck
 
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Old 07-22-05, 12:28 AM
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Also, keep in mind, concrete does not meet true compression strength until its 28 days dry.
You will need to disconnect your services, rent a porta-potty and set a power pole.
What are your soils condition, does your project require an affirmation that the general soils condition are an assumed quantity and will, without special ammendments, support conventional foundations.
 
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Old 07-22-05, 07:36 AM
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Unhappy Many Thanks to You Both!


Well I was afraid this sort of thing was going to be the case...

As for the lifting and remaking the foundation, how long does it take to pour/build a foundation under a small house such as this? If most movers won't leave the house up for more than 30 days and concrete doesn't properly set for strength, for 28, is that enough time to get the foundation poured, and let it set up?

Any other ideas or suggestions would be greatly appreciated....

BTW Jack, are you still in the area? Wanna project?

Thanks,
RhainyC
 
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Old 07-22-05, 10:08 AM
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Rebuilding Foundation and Raising House

Forget the fables and balony about the 28 days for concrete. The 28 days is the time it must reach its specified (not ultimate) strength.

Concrete begins to gain strength immediately after it is placed. Typical 3000 psi concrete will be 2000 psi after a couple of days since the fastest strength gain is the first few days. Concrete continues to cure indefinitely as long as it has a source of moisture, so some 3000 psi concrete ultimately can be 4500 psi.

It is possible to achieve 3000 psi in 2 days (which you really don't need) by just ordering the correct mix. It is done every day on commercial jobs. It will cost more (10% to 25%), but is worth it in terms of time.

A higher specified strength (4000 psi or so) and the use of high early cement (Type III) will do it. You local supplier knows the best combination of materials.

Be careful if you use this approach for a concrete slab. The cement finisher cannot work fast enough to finish it properly on a warm day and people will be driving on it in the next couple of days.

Dick
 
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Old 07-22-05, 07:52 PM
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Rhiney:

Concretemasonary is correct. If you pour on Monday, you could set the home of the foundation in about 4 or 5 days. In many commercial jobs and also residential jobs. We pour on one day and start work on day 3. Not a problem. Now, I am in the midwest now. I was out there 3 weeks ago, for a job in Puallup. That is done and now am back here.
Good Luck
 
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Old 07-22-05, 08:55 PM
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The house mover will charge you a bid price for a lift and place. If you anticipate the house being supported on beams and cribbing for an indeterminate length of time, its good business for them to ask and you to discuss the terms of.

[QUOTE] Forget the fables and balony about the 28 days for concrete. The 28 days is the time it must reach its specified (not ultimate) strength. [QUOTE]

You are free to believe that this a fable and/or baloney.

Every plan that I have ever prepared or presented a bid for, that had a foundation associated with it, had in the general notes verbiage similar to the following: Transit-mixed, poured in place concrete shall be of such consistency to attain a minimum compressive strength of _______PSI at 28 days dry.

I used the term "ultimate" as the minimum design standard acceptable to most building officials in the support of residential construction.

While the concrete may reach its design compressive strength in less time, the building dept. will tell you when they will allow you to load the foundation
and if they will accept that your certification from the transit-mix company
of the mixes consistency, or they may require you to provide and pay for a core sample testing.

Generally, within a couple of days after the foundation is placed, it is built on
(loaded) and the load slowly increases, as does the strength of the concrete.
In your case the foundation will be instantaneously loaded at approx. 15 tons.

The final determination of the methodology for your project lies with the local building authority. Do your homework.
 
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Old 07-22-05, 10:37 PM
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Rebuilding Foundation and Raising House

Codes refer to specifications and standards that are established by organizations such as the American concrete Institute (ACI) and the American Society for Testing and Materials (ASTM). The term ultimate strength is an engineering term and has no bearing to a specific 28 day time period. It refers to the ultimate strength determined at the time of a test, which may be run at any time. There is a difference between code language, which is enforceable and engineering terms, which are descriptive.

The 28 day strength is a "specified strength" commonly used to describe a strength level at 28 days. Loads less than the design loads may be placed on concrete less than the specified strength if it can be shown that they will not create stresses higher than the actual strength with a safety factor applied. The design loads include the combination of occupancy loadings, wind, snow and seismic forces and are much higher than the dead load of the structure.

This is one of the reasons 7 and 14 day tests are conducted and the age-strength relationship are recorded and established for different mix designs. A central ready mix supplier or a good transit mix supplier knows the strength gain rate and strength levels for commonly used mixes.

I am active in the writing of numerous international and domestic codes in addition to writing specifications and inspection of structures.
 
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Old 07-23-05, 06:03 AM
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Well, you are certainly receiving an education about concrete and its placement in residential application, as well as a longer list of question to ask.

The specified compression strength attained over a specified dry time is a minimum standard established by your local building authority, by which your compliance with, they will allow you to proceed unimpeded with your project, within the parameters they have established.

You are absolutely free to hire and engineer to establish a different design strength than the local established/acceptable standard.

The local building authority is absolutely within their right to also accept, as a standard, an assumed soils condition.

(Engineering is an exact science, based upon assumptions,)

They are also absolutely within their right, at their discretion, to require you to provide a soils test in conjunction with the engineers calculations.

While engineering may be "descriptive", it is the exact description that absolutely must be adhered to obtain the results of the design.

Should you elect to tie engineering to your project, understand that the incumbency for the building dept. is the same as were you to conduct your project using standard acceptable methods, compliance. What they require of you to meet those compliance standards, comes out of you pocket.

Do your homework. Choose your battles well. Its your time and money.
 
  #10  
Old 07-25-05, 10:49 AM
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Thanks To All Three Of You!

I have made notes and am doing my homework as suggested!

I will see how much it is going to cost to raise and redo the foundation...we may be better off razing the house and putting a modular on the lot...

Thanks for the input and suggestions, and education on concrete and such!

In Thanks,
RhainyC
 
  #11  
Old 11-19-12, 02:01 PM
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Raising House

Hello Rhainy

Having read all of the above posts i have become more informed. Thank You to all who posted! I was just curious if you'd gone ahead and lifted your cottage and constructed a new foundation? If so, i am curious as to roughly how much this project costed you? How long did it take? Was it worth it?

thanks for any info!

I live in Canada, there is a house i am interested in. The foundation walls are leaning in, and there are other problems too............however, i've begun the wild and animated (and i have to admit, kind of exciting!) thought process of having the house lifted and replacing the foundation. At this point i am just seeking info on the realistic-ness of a project like this, as well as some kind of ballpark idea of how much it might cost in the end.

Hope you are now enjoying a home on a solid foundation!
 
  #12  
Old 11-19-12, 03:12 PM
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It's a 7 year old thread. RhainyC hangs out in the pet/animal/pest area. I'll PM to see about getting you an answer.
 
  #13  
Old 11-19-12, 05:35 PM
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Older thread

Thanks to both of you.

Yes, i realized after quickly registering and writing my comment that it was an older thread. Was actually surprised to get a response! Thank you. although this thread is old, the problem it discusses is still valid today!

Kind of sad to hear that the cost of the cottage turned out to be more than the house value. That's how it goes i guess.

Will be looking at a 'leaning wall' tomorrow and will keep all of this in mind. Again, thanks for taking the time.
 
  #14  
Old 11-19-12, 05:50 PM
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Hey, hope we were of some help. C'mon back.
 
 

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