# Putting Footings Under Existing Slab



## shirken3

We have a cement slab on the side of our house where we park our 36 ft motor home. We recently installed a 17'x40' metal cover for the motor home. (looks like a carport but bigger) We've been told that we need footings in order to get a permit to keep it otherwise we have to have it dismantled (its a long story why we didn't get a permit first). My question is: Is there a way to put the footings in at this stage and how much does something like this cost?

Thank you


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## concretemasonry

Since you did not give your location or much else, you will only get guesses about and approximate cost.

In general, you must provide footings at each of the vertical posts (however many you have). If it is supported by you home, you will additional problems.

For a lightweight cover, you just to to edge it up a bit to remove the supports and build some acceptable foundation, replace the posts and lower the cover as you removed the temporary support. You might get lucky and be able to do it one post at a time.

Since you tried to avoid a permit or inspection, you can be expected to be watched closely. I would imagine you may need some kind of soil report to verify the design and ability to provide sufficient vertical capacity and lateral strength/stability. You might even have to provide a way to provide anchorage methods to prevent owning a 17'x40' "wing" flying around the area.

edit - To put footings under the slab, you can cut holes wherever needed, excavate for footings (Sonotubes or concrete piers or similar) and then patch the concrete slab.

Dick


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## shirken3

*Footings Under existing slab*

Thank you for the information. I am in San Bernardino county in Southern California. Any idea of cost? I know you cant be exact but are we talking hundreds or thousands to have something like this done? The RV cover cost $5000 to have installed so obviously I don't want to pay more than it cost me to have footings put in. It would be cheaper to just let it go.


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## joed

Costs vary too much by location. Call several contractors for estimates.


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## Nailbags

well how thick is the slab?and what type of footings are they requiring? pier type? a full length perimeter footing? how thick do they want the footing 6", 8" or 10"
These are all the questions we need the answers to. In order to provide more suitable replies. I will say this to all who read this post. Get a permit when it is required! it is cheaper in the long run and they will work with you.


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## Nailbags

shirken3 said:


> Thank you for the information. I am in San Bernardino county in Southern California. Any idea of cost? I know you cant be exact but are we talking hundreds or thousands to have something like this done? The RV cover cost $5000 to have installed so obviously I don't want to pay more than it cost me to have footings put in. It would be cheaper to just let it go.


Why not use something like this? 
http://www.sheltersofamerica.com/productdetails.php?productid=655&id=3
It is not a permeant structure and hence you might not need footings.


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## concretemasonry

Definitely not a permanent solution with two problems.

1. It will last until the first good storm and has no real guarantee in the end.

2. If the home is put on the market, a quick look would be to devalue the actual home (it is bad sign of things to come). Even when sold, it will be reasonably easy to dispose of (some labor and a couple of loads).

Dick


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## stadry

dick, looks like the beverly hillbillies've moved in but, at least, you wouldn't need a bldg permit,,,,, OOOPS  wait a minute - this is in KALLEFORNIA ? ? ? you might

irc


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## ChrisMDL

Concrete masonry is right. My guess would be pier footings at all the point loads. You can build temp supports are puns each vertical point load. Then cut the concrete and dig and dig and dig. Inspector will then come out to check the depth. Then get some sonotubes and pour the footers. Ask the inspector what he would like to see for your attachment method to the footers. I would flare the bottoms of the holes and throw a few inches of gravel. This will help if that wind kicks up and that"wing" goes up and takes the footers with it. 

I would also pour concrete higher than the existing deck in order for you to slope the top of the pour I'm order to shed water. This may require jacking up the car port to accommodate. 

By the way you described it, it doesn't seem like this is a job you would tackle yourself. Start getting estimates.


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## ChrisMDL

Edit: "build temp supports at each vertical location/ point load"


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