Hi Roy
At a guess I'd probably use three, it depends on how well I think the wall will stay together and if there's any other weight on the wall from above. You need someone to be there and look at it to be sure.
You have to support both ends, you'll see this as the job is being done. Either by taking the acrows through the floor or as noseall said by sitting the needles on the floor and then jacking the joists below the needles.
Normally I wouldn't try raising the wall, as it lifts you are going to get cracks in the plasterwork at the least and every time you alter something by lifting that will affect something else.
If I was going to try and lift it I'd do it using the bressemer before cutting for the needles. Don't do this yourself, leave it to your bulider, he'll have insurance. as woody said, if it goes wrong it goes wrong quick, you'll get no warning. Then if you're really lucky you'll only have a massive bill for putting it right, and if you're unlucky, don't even think about it.
Good luck with getting the builder at right price for you. There are guys out there who will give you a good job at a good price but accept you have to pay the right price. I bet you reckon you're worth every penny you get paid, the builder will be the same.
At a guess I'd probably use three, it depends on how well I think the wall will stay together and if there's any other weight on the wall from above. You need someone to be there and look at it to be sure.
You have to support both ends, you'll see this as the job is being done. Either by taking the acrows through the floor or as noseall said by sitting the needles on the floor and then jacking the joists below the needles.
Normally I wouldn't try raising the wall, as it lifts you are going to get cracks in the plasterwork at the least and every time you alter something by lifting that will affect something else.
If I was going to try and lift it I'd do it using the bressemer before cutting for the needles. Don't do this yourself, leave it to your bulider, he'll have insurance. as woody said, if it goes wrong it goes wrong quick, you'll get no warning. Then if you're really lucky you'll only have a massive bill for putting it right, and if you're unlucky, don't even think about it.
Good luck with getting the builder at right price for you. There are guys out there who will give you a good job at a good price but accept you have to pay the right price. I bet you reckon you're worth every penny you get paid, the builder will be the same.