I want a 4 meter load bearing wall knocked through on the ground floor. Upon inspection with the Structural Engineer the ceiling joists run parallel to the wall. There is also a wooden joist sandwiched between the ground and first floor wall. His recommendation is to replace the wooden joist with an RSJ to be sure. My question: Can the wall above be temporarily supported from the first floor joists (that run parallel) while the wooden beam is removed and replaced with steel?
In theory yes, in practice no, to much weight for the joists. You could though punch some holes in the upper wall fit some 4" x 2" timbers sideways on, spanning 3 joists each side. Then support this from below with Acrow props.
Thanks Phil. We have laminated floor on the first floor and avoiding taking this and floor boards up would make a large cost benefit. Am I understanding you correctly that the 4x2 would rest on the floor boards (and laminate) with everything supported underneath with Acrows?
Yes that it exactly, just make sure the acrows sit on the underside of the joists, 1 acrow every 1 metre should do.
How does he knock holes in the upper wall, yet still install 4x2 under the joists which are below the upper wall? Mr. HandyAndy - Really
He doesn't, he knocks holes in the upper, puts the 4x2 in on top of the upper floor, wedging them tight to it and the wall, then supports it below with acrows, save taking up the floor upstairs.
So the whole upper wall is held up with say 4 cross-pieces(32" in length) of 4x2! I'm off to bed now, so any replies............ Mr. HandyAndy - Really
Not quite, it has the joists and acrows for support, but yes the direct weight is on the 4 x 2 in the space between the first two joists, this is a very common way of doing such a job. Explain how you would do it differently?????
I prefer to use the proper steel pins/ needles beams not 4x2. Lay a sheets of hardboard on the floor to protect laminate flooring. I prefer & it's easier to use a 4" or 5" core drill to put the holes through the wall, less damage to plaster & much quicker than chopping a hole through the wall. You could square up top corners, but I never bother.
Absolutely KIAB ,but the OP not going to have that equipment available to hand. I'm doubting to upstairs wall in going to be that heavy would imagine is an old type internal block wall so the 4 x 2 should be ok, could always use something bigger if unsure. But yes even going and hiring a core drill would be a good idea.
I have a couple of mates who have a core drill going that's free to collector in the Hatton Garden area!
Don't mention it phil at least chippie noticed So chips how is everything at work? Keep it to a minimum though wouldn't want to go off topic or anything