advice needed for foundation repairs pls

Hey all.. Ok here's a doozy guys. I'm a very handy person, not a full carpenter tho. Here's my problem. My mom lives in a house near the river. It's a cottage like place, and after yrs of moisture and I guess poor workmanship the floor is starting to sink in various spots.( im guessing no hangers used and water rotting a little) even tilt the house a bit. when standing outside yu can see minor dips etc in the roof. Inside its basically sound. Normally I'd send some joists through the house, get some jacks and rebuild the foundation posts.(theres no basement) however, after the hom,e was built, someon build a small addition on one of the corners that sits just fine. so sending joists straight through wont work. whats my best course of action? rip up floor, redig posts and lift it a bit at a time? this may seem a little vague but any help or suggestions would be greatly appreciated.
thanks in advance
rc
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Sounds like you're in for a complete rebuild - a piece at a time. You will need a long range plan based on knowledge of existing conditions. Check soils. "Near a river" suggests high water table & poor bearing values. Check foundation of addition & compare with foundation of earlier work. Plan on new continuous footings.
Jack up early construction to match newer. Bring through beams to a fraction of an inch lower than "good" construction. Raise the rest of the through beam a bit at a time to lift entire house to same level. TB
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.