Concrete Slab Foundations for Mobile Homes

I am in the process of buying a double-wide and am considering to set it on a concrete slab foundation. I have no experience with this and also cannot find any good references. Should I hire an engineer to design the foundation? What are the specifications? What are the costs involved? I would greatly appreciate any help from people who have or do use concrete slab foundations for double-wides.

Thank you in advance,

Alexander H.

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The guidelines I have always followed in regards to permenant foundations were provided by the mobile home manufacturer, the city or county in which I was performing the work in or a engineer. I would make calls to all the above for advice.


P.S. Keep in mind I come from a construction developement background in CA. were we have earthquakes and our foundations are built to withstand an atomic blast

Alexander, the goal of concrete under the supports of the home is to avoid frost heave. If you live in an area in which the soil does not freeze in winter, there is no benefit to having concrete placed below supports. You will need to determine your soil type (use pernometer) check with manufacturers specs for the size of base pad for your geographic area. Make sure that your grading is such that water flows away from house, do not create places for water to pool under home. use a vapor barrier, and make sure to vent dryer outside skirting.

The main reason for a permanent foundation with a mobile home in my experience was to get a loan from a bank. This business is so regional and area specific. CA is a real pain

Thank you for your responses. We do not have frost heaves in out region. The city and local banks have no standards for concrete slab foundation. One bank suggested to use FHA standards, but couldn’t tell us what these standards are. Mr. Sisco, could you give me details about a vapor barrier please.

Thank you,

Alexander H.


I’m assuming your are much like us as far as zoning but you should really check with your zoning department as they are the ones who can tell you what you need to do along with a FHA mortgage broker who can get you a copy of the FHA requirements.

With that said here we are required to lay a full vapor barrier, shear wall the blocks, (it’s a weird fiber coating) apply masonry underpinning, and retire the title per county/state regulations. Occasionally they will also request updates to the decks to bring them to the new county codes.

I’ve found that this is a very local issue from talking to people, Steve can use vector systems and get an engineers certification bypassing most of the crap we have to go through to appease the county I’m in. There is no reason to spend money to make someone else’s jurisdiction happy, get the local scoop and tailor your methods to suit them

Best wishes,

Ryan Needler

6mil sheet polyethelyne, it is available at your lumber yard. Ryan posted regarding FHA. If you are attempting to have your MH installed in such as way as to be FHA-VA financable, my advice to you would be to meet with FHA-VA inspectors from your area, and find out what they will-won’t approve. I have seen these standards be tightened (must be on poured foundation, must be on county-state maintained road) loosened (block foundation is OK) loosened more ( vinyl skirting OK-private drive OK) and now I suspect tightened back up again. So, it is no wonder that you get conflicting info, depending upon whom you talk to.

To all the people who have replied to my query, I would like to give thanks to you all. I greatly appreciate your help and advice. One thing that i forgot to mention was that I am currently doing my first solo deal.

Thank you,


Alexander. you will do fine. If you need help or want someone to kick it with you call me…I am 13 hours away by truck or 1 minute by phone or email…you’ll have to feed me if I come over tho! LOL

alexander, cheaper is better. In FL we need 3K pound reinforced concrete and 6" holes cored for anchors. Cost around 5K plus engineeering seal.

Why do it? FHA requires strips only and unless your exit is VA or FHA resell why bother?

Give us some details and i mean it about being 13 hours away…plus I have had nothing but c**p BBQ anywhere outside of TX. You are up around Nagadoches aren’t you??

You really are a very cool guy, we need to hang out some time…you come down here, I come up there…maybe both learn something new.

Before you buy a repo call me…


352.216.2020 Cell

Infinity Homes, Inc.

11950 SE Hwy 464

Ocklawaha, FL 32179

352.288.0046 Office


What is it you are trying to do? That is, why would you want a slab anyway?



Congrats on the solo deal!! Can’t wait to hear you at MOM.

One thing I learned when putting a REPO home on a private lot is it can NEVER be sold FHA. Not because the home is a repo but because it has been moved more than once.

Definitely consider what your exit strategy is on this deal and only do what is necessary for your situation…IMO.

Good luck, keep us posted.




I have never heard of this rule. Can you elaborate a bit? I am considering buying 2 empty lots with the intention of moving used doublewides on them. Does FHA give a reason for this rule?


Cole, Dennis, I too had a used home that had been moved and was diqualified. However, 6 months later another used home that I had already set on a lot was deemed to be just fine. I was listening to Lonnie on a teleseminar, when asked about sec.8 rentals he replied something to the efect of “the less I have to deal with government, the better off I am” I too am in that camp.


I agree with you. I have seen homes get by FHA after being moved more than once. I think that is bc of an oversight by the underwriter in some cases when signing off on the loan.

I have sold about 10 homes now FHA and it never is easy. But they are building my rental portfolio so Im playing by all of their rules for the time being.

Dennis, from what I have been told they disqualify homes moved more than once b/c of settling issues. I dont understand it but that is how it was explained to me.

I would charge about 6 to 8 dollars a square foot for pads like that typically depending on codes and inspections in your area. Concrete could cost between 130 to 180 per yard. Also depending on the weather would also impact how long you would have to wait after the pour to set your home. Hope this helps or at least gives you an idea