JamesSmith79

Thats absolutely an option but for a 70mm lift, surely that will make things tough with doors etc. Everything will have lost 70mm at floor at the lowest point. This just so happens to be where the doors are. There are a few doors in this masonry center wall. How would one rise those 70mm? I actually thought the idea of dropping joists on one end could be cheaper and quicker but probably not. If this was easy other people with similar issues would do it. I haven't seen any example online of dropping down joist ends!

Thanks for the comment Gus! You are absolutely correct, the building has almost certainly settled a bit. I don't believe ONLY the center went down in the last 50 years, the external walls must have settled even a fraction over the last 50 years. If I went with idea A (Cut pockets under joists into external wall(s) cavity leaf so joists drop down.) I can't see how any load paths would change too much. This is on the presumption of all the partition stud walls upstairs not actually bearing anything and only this centre block ground-to-roof bearing wall. Now idea B is where load paths definitely shift. This central bearing masonry wall will literally be lifted roughly 60-70mm at worst. There is a beam directly on the end of this wall in the roof so an element of the roof would raise. A further element complicating all of this is two presumptions; A) That the house was ever 100% level. Were all walls always totally level? Were joists level? and B) determining where everything is right now. If the back external cavity wall is down 20mm itself as an example, then this has to somehow be factored into idea B if any lifting was to be attempted. Say I could somehow calculate this, even attempting idea B would be tough. Disconnecting the top half of the wall from the bottom would be the easy bit, how would one even lift? One dea would be to just put a beam adjacent to the wall under the joists and lift. This though is relying on the 2" of 7x2" on 12" centres literally lifting an 8ft wall above, not to mention the portion of the roof, the joists etc. 10m width/304mm centres is 32/33 joists for the length of the house. That is roughly 1700mm of joist end coverage width "touching" the wall. So jacking the joists would mean lifting directly 17% and hoping it will take it all. Thats not taking into account the strength of the wood, how deep its actually pocketed into the wall etc. Another option would be to support the cut wall above (With a lot of stongboys!) and every x m pocket in a bottle jack into the lower wall to directly lift above.

Hi folks, I have an admittedly crackpot idea to level the first floor in a doer upper I have. There was a significant leak some years ago in the property which caused the center to settle a couple inches but it has since been underpinned there with mass concrete etc well before me. The issue I am having is sloping floors upstairs. The drop is up to ~70mm at worst (Probably over 4m). Under foot it actually doesn't feel the worst but as I am doing a full renovation here I thought now would be the time to sort or never at all. I have looked up all options related to sistering, shims etc. One idea that was proposed to be was to make the high sides (external walls) lower as opposed to the other way around. The joists are all pocketed into the block cavity and mortered in. Then the other ends are pocketed into an internal 100mm block wall that goes up to second floor ceiling (5m or so) The idea is essentailly to cut pockets below every joists and drop the joist down. This will lower the floor and even out the slope. Bar that one block wall in the middle, all the others are partition stud, so either should fall with the floor or stay on the ceiling. Both would be repairable. Is this absolutely an off the wall idea or possible? This is idea A, idea B is even more drastic. This 10m wide, 5m tall wall is holding the first floor joists so lifting the joists is impossible. What if a consaw was used to cut near the ground floor ceiling. Obviously using acrow/strong boys to support as we go. This would unlock the wall and joists above. Now we have an 8ft wall below and an 8ft above. Then from below we could jack up the first floor joists and wall....somehow. My crude drawing. Two external cavity walls with one standard internal 5m (Both floor) block wall. https://freeimage.host/i/FAZOkEx