Alternative Foundations

This concrete slab on grade is one example of an alternate foundation.

I know that through the years a lot of community owners have hired professional engineers to design foundations for homes installed in their parks. Many times, these foundations are elaborate, well designed, and constructed beyond the minimum requirements of the installation standards.

 In some places, these foundation designs were also reviewed and approved by the state, county or local code official.  With approval from engineers and building code enforcers, what could be the problem???

 Well grab your “Model Manufactured Home Installation Standard” and open to section 3285.2(c)(1). It says that BEFORE an installer provides support or anchorage that are different then the installation instructions, or if the installer encounters site conditions that prevent the use of the installation instructions, the installer MUST:

  •  Try to get DAPIA approved designs or instructions from the manufacturer; or
  •  If the designs are not available, have designs prepared and stamped by a professional engineer (or architect), and submit these designs to the manufacturer for their approval, and approval by the DAPIA!

After a few modifications, this foundation was manufacturer and DAPIA approved!

 Basically, any foundation system that is not addressed in the manufacturer’s installation instructions would be considered an “Alternative Foundation System”. It would need to be approved by the manufacturer and their DAPIA before you can use it to support/stabilize a new manufactured home. Ultimately, the manufacturer needs to agree that any alternate foundation will properly support and stabilize their homes.   

 So, if you are placing new manufactured homes on anything other than a typical concrete block pier with individual footings that extend below the frost line, and a ground anchor tie down system, you have a little paper work to do.

 First off, do you follow an actual design plan for the foundation you are constructing? I know far too many installers follow  the “way we have always done it” plan. If it is a concrete slab or a purchased system from a supplier, or something entirely different, make sure there is a design to be followed and make sure you follow that design.

 Next, check through the manufacturer’s installation manual for the home. Some installation manuals provide the installer supplements that address a wide verity of alternative foundations. For example, certain manufacturers provide DAPIA approved designs on placing their homes on steel crossbeams in masonry crawl spaces and basements, and others have DAPIA approved designs for concrete slabs. Most have DAPIA approvals for alternative anchoring systems. Grab the most current manual from the manufacturer and see if your foundation is addressed. If it is, make sure you read all of the little notes and disclaimers so that you are in full compliance.

 If you can’t find any designs for the alternative foundation you utilize, call the factory’s Quality Assurance Manager and ask him to help. It is possible that the manufacturer already has designs that can help you.  Don’t ask the sales department, service department or supplier about design or code related issues. The Quality Assurance Department is your best bet.

 A word of caution, I have seen foundation products from supply houses that appear to be approved by a DAPIA, but the specific manufacturers approval is needed as well.

 So, before you get too deep into your busy season, take some time and make sure you:

1.       Have a manufacturer and DAPIA approved design that clearly addresses the foundations you construct for new manufactured home installations.

2.       Make sure you read all of the fine print, notes, instructions, and limitations of the designs you are using.

3.       Make sure you follow the designs!

4.       Make sure you have copies of these designs for your records.

5.       Take a few pictures through the process.

Bottom line, make sure you have a design from the manufacturer that has a stamp showing it is DAPIA approved for every foundation type you construct!