Evaluating Your Foundation For A Lift
First, foundations can be grouped into different groups.
1) Slab on grade—typically poured concrete
2) Raised masonry or concrete walls with wood frame platform-just like it sounds
3) Raised wood posted-just like it sounds -or-
4) a combination of some or all of the above
Next Can You Use Your Existing Foundation as a Base For a New Taller Foundation?
First, Foundation 3) will almost never will work, so eliminate and build a brand new foundation.
Second, what is the condition of your existing foundation?
Does it look crack free on the exterior walls? Do your floors sink or slope down in areas? Do your floors have temporary looking posting (typically wood stud cutoffs) under the flooring somewhere in the middle of the crawl?
Chances are if your foundation is crack free and you have sturdy looking postings or piers than it may be used as a base for a new taller foundation, saving a considerable amount of money and time.
If in doubt inspect the footings or walls further. Moreover seek out a good foundation professional.
Michael J. Drake Jr P.E.
4619 Captree Island
Captree Island, NY 11702