Replies

1. 
   dovetail97128 | Mar 16, 2008 08:35am | #1

   Can you help us out here by telling us how the house is constructed?

   Floor joists at what centers, or post and beams , or balloon framing to the sill?

   Different styles of construction mean different approaches to the problem.

   They can't get your Goat if you don't tell them where it is hidden.
1. 
   KFC | Mar 16, 2008 09:07am | #2

   Yeah, thanks for the interest and (i hope) help.   It's a 90ish year-old 2-story platform framed house, on a slab on grade poured out to the perimeter footings.   It's roughly 30x40' in plan, and ideally we'd do an entire side at a time.  And yes, the interior is just finished.

   We can pull the exterior siding easily.  Working from the outside, we imagine we'll carefully cut out the framing 16" or so up from the footing (with as little damage to the new interior as possible) and add 4x's that will carry the existing studs while working, and pour a stem wall up to those 4x's, leaving them bolted in as a new plate.

   But what holds those 4x beams up while we're working? Jacks would be in the way of the pour.  Perpendicular beams under them would need to penetrate the walls (and cabinets, etc.) and sit on blocks inside.  The other GC (the GGC?) has an idea to pour (as we work along a wall) some blob piers below where our new footing will be and use all-thread with nuts and bearing plates to support the 4x's.  We can then pour right around those, no problem.  They can even be the anchor bolts.  But will all-thread every six feet support a two-story house with an attic in compression?  I wondered about pipe, but it won't cohere in the footing and stem wall as well.

   help...

1. 
   dovetail97128 | Mar 16, 2008 06:12pm | #3

   I am thinking on this one. I have never dealt with a slab on grade perimeter foundation replacement. In the mean time this will serve as a bump and keep the thread alive for others to read and reply to. Why the need to build the foundation walls though or is that just a proposal as a method to achieve the end result?
   They can't get your Goat if you don't tell them where it is hidden.

1. 
   KFC | Mar 16, 2008 07:20pm | #4

   The only real need for the stem walls is to get the new framing a little higher off grade- termites and whatnot.  Mostly it's just to replace the framing we're going to have to surgically carve away to make room to work. 

   Thanks for pondering...

2. 
   brucet9 | Mar 16, 2008 08:09pm | #5

   For the benefit of those of us who want to learn more, can you tell me what it means for perimeter footings to be "rolling"?

   Thanks

   BruceT
1. 
   KFC | Mar 16, 2008 08:39pm | #6

   The exterior walls are bearing directly on (90 yr. old) continuous concrete perimeter footings.  Over time, these footings have started tipping over to the outside.  Once they tip a little, the downward force of the wall load tends to make them rotate even more.   The stud walls themselves are kicking out at the bottom, and the footings are "rolling" over top first.  Imagine if you were standing on an upside down 5 gal. bucket and it tipped over a bit.

1. 
   dovetail97128 | Mar 17, 2008 04:13am | #10

   I think river has it pretty well dialed. I might be putting a set of supports inside the building and from slab to ceiling/upper floor joists on the walls that are bearing walls for the second floor and roof load once I jacked it free of the existing foundation.
   Added security. I also would not touch any more of the existing wall then needed, no sense in it . Create just enough room to work with shim stock and leave the finished surfaces finished.
   They can't get your Goat if you don't tell them where it is hidden.

3. 
   Riversong | Mar 16, 2008 10:45pm | #7

   If you don't need to raise a stem wall, then leave those studs intact unless they're rotted - no sense in risking the interior finish you've just installed.

   Remove siding and lag a ledger near the top of the first floor stud wall and lean jack posts far enough out to give clearance for working below (see picture).

   Then lift weight off of existing perimeter footings, remove and replace with wider bearing surface to prevent rolling - stud wall should bear on center of footings to be safe, and you will have to flair a skirt board to cover.

   Pour new footing to within 1/2" of existing wall plate.  Then shim with 1/2" PT plywood to keep framing off of concrete, and tie in with anchor straps embedded in footing.

   View Image

    

   Riversong HouseWright

   Design *  * Build *  * Renovate *  * Consult
   Solar & Super-Insulated Healthy Homes
1. 
   KFC | Mar 16, 2008 11:14pm | #8

   Thank you very much.  I'll show this to my partner.  Did you stake the bottoms of those jacks, or do they not want to kick out too much?

   Any guesses as to whether we can support an entire 40' side that way? 

   thanks again.  this does look like pretty much the same situation.  what was the story on that project?

   k 

1. 
   Riversong | Mar 16, 2008 11:20pm | #9

   I don't stake the jacks, I slope the ground to the correct angle and place a chunk of 2x10 or something down as a base and set the jack on that.

   You would probably need a jack every 8' and would need to double the ledger or use a 4x to span that far.  Make sure the jack posts are tacked off to the ledger and they have solid bearing under the ledger at the right angle (a little birdsmouth).

   The story on that project is at 102206.38  

   Riversong HouseWright

   Design *  * Build *  * Renovate *  * ConsultSolar & Super-Insulated Healthy Homes

1. 
   KFC | Mar 17, 2008 04:49am | #11

   awesome.  thanks big time.

   k