Question about tipping up walls?

[MushCreek]

I've built and tipped up plenty of walls; you'd think I'd know the answer to this, but I've never built on a concrete slab or wall. For my barn, I'm going 4 courses of split-face block, and then conventional stick framing on top of that. The block walls will have embedded J-bolts to attach the mud sill to. I'm going to build the walls on giant sawhorses, and then tip them up. The question is- how do you line up the J-bolt holes as it tips up? I drew it up to scale, and it looks like you'd need about a 1-1/4" hole for a 1/2" bolt. Would I just drill (way) oversized holes, or would I slot them, or would you get them started as the wall goes up, and hope they drop into place once nearly vertical? I'm going to tip them up with wall jacks. If I could afford a crane, I could just drop them into place, but this is gonna be low-rent, backwoods engineering. They're going to be fairly big, heavy wall sections, too, so muscling them into place may or may not work.

[ChuckinVa]

Lay your mud sill (plate) out and mark the J bolt locations before you build the wall. then predrill the holes the correct size for the Jbolts.

[Don_P]

You can also bolt down the sill and then build the wall with a bottom plate that has oversized holes, tip up and nail the 2 bottom plates together well. It's sometimes easier to frame it a stick at a time standing in place.

[JRR]

Attach temporary several scrap 2x4 "stilts" to the wall detail ... roll it all up.  The stilts should be tall enough to have the wall-sill above the bolts.  Use stacked-spacers under sill ... remove stilts ... lower wall.

[bayview]

   Unfortunately I don't have the answer for you. . .    But as  ChuckinVa advises, lay out the sill, mark out where the j-bolts go and pre-drill.

   Do not enlarge the bolt holes!   The lumber will dry out - shrink.   Possibly allowing the mud sill to move.

   I built my walls in 12 ft sections and had to "muscle" them into place.   Supported to the ground with stakes.

/. 

[firefox]

I think JRR has the right method. Put a couple of scraps nailed in place
to keep the wall in place while you are removing the shims to lower it so it
doesn't get knocked out of alignment with the j bolts if it gets bumped.
ie a guide to make it go smoothly into place.
Bruce

[archimedes]

I watched a guy build a garage around here using these (or something similar);

http://www.concretefasteners.com/anchors-fasteners/sleeve/index.aspx

He put the walls up first then anchored then down.  I was kinda surprised,  since I didn't think that was allowed.  Doesn't mean it's ok to do it that way,  just telling you what I saw.

Maybe you can ask the building inspector it that is ok.  Seems much easier that way.

[rocking23nf]

lay the bottom plate on top of the bolts, give it a whack with your hammer.

This will leave a mark on the bottom of the board where the holes will be.

Drill them out a bit larger, and it should fit like a glove...

[John Raabe]

I would follow-up on Don_P's suggestion: Put down the PT sill plate first and then frame your wall with a 2nd bottom plate and tie the two together with nails, the sheathing, and straps if needed.

If you want to do it all in one tilt-up wall, sill plate attachment can be made easier by alternative foundation to wood anchors such as these:

http://www.strongtie.com/products/connectors/LMAZ-MA-MAB-MASB.asp

[MushCreek]

Lots of good ideas here! I think what JRR proposed will work best. I drew it up today and animated it, and it will work well. I could cut a radius on the end of the 2X4 strut so it pivots easily in the corner between the slab and the CMU wall. It can't go anywhere, as it will push against the corner. Also- I can build the wall flat on the floor rather than up on horses. I don't know if anchor bolts are code for this application or not, but I prefer the security of J-bolts. Hopefully I'll have pictures of the process in a few months- it may help someone else doing a similar build. Thanks!

[firefox]

One thing you could do for a controlled descent would be to
countersink underneath the bottom plate of your wall in a few places
and push a nut into it along with a hole to screw a long bolt into it from the top. ie bolt goes thru the plate, threads into the nut and down to the concrete. Then when you remove the stilts, you can slowly back out the bolts and lower the plate onto the j bolts.
Note: the counter sink should be slightly smaller than the nut so that the nut is kept from turning.
I hope that is clear enough. I am thinking a 5/8 bolt should do it.
Bruce

[JRR]

Another way to have "controlled descent" is to use jacks..... either bottle or garage floor style jacks.  By installing some temporary diagonal "V" bracing across the studs, each wall could be lowered by support at two points.  (I like temporary rigging ... makes for a fondness for deck screws.  Easy to assemble and disassemble.)

[MountainDon]

I like the idea Don_P presented. Build the wall in shorter sections and then nail it down on the PT plate that is bolted down.

[MushCreek]

One thing you could do for a controlled descent would be to
countersink underneath the bottom plate of your wall in a few places
and push a nut into it along with a hole to screw a long bolt into it from the top. ie bolt goes thru the plate, threads into the nut and down to the concrete. Then when you remove the stilts, you can slowly back out the bolts and lower the plate onto the j bolts.
Note: the counter sink should be slightly smaller than the nut so that the nut is kept from turning.
I hope that is clear enough. I am thinking a 5/8 bolt should do it.
Bruce

I was thinking of something along those lines, using T-nuts, which bite into the wood from underneath. I'll have to see what sizes they make.

As I jack the wall up, I'll have a rope on the inside to prevent over-travel, and at some point, I'll have to trap the bottom of the stilts so they can't kick out on me. Once reasonable plumb, I'll secure diagonal braces from the outside to hold the wall up while I mess around with jack screws or whatever. I can run the jack screws down to take the weight off of the stilts, remove the stilts, then lower the wall slowly into place.

My thought is to buy a couple of electric winches to make two wall jacks, rather than cranking them up by hand. In a pinch, I could even control both of them with remote controls, and stand walls up by myself, although I plan to have help. I figured the winches would pay for themselves by hauling sheets of plywood up on the roof, etc. I did that on a roof-over job once, making a crude ramp to the edge of the roof, and clamping together 3 sheets of sheathing, and hauling them up with a re-purposed 12V boat trailer winch. As I get older, I think of more ways to cut down on sheer physical labor......

[firefox]

Definetely T nuts. I was just tryin to keep it simple. I have a tendency
to scare people off by giving too many details.
You're not going to believe this, but one of the things I was going to suggest was to get some long 2 x 12's and secure them to the corners of the foundation so that they point strait up. Then mount one of those $58 12 volt winches with remotes from HF to the top of each post. then pull the
walls up with both lines. If you don't have power yet you could attach
to your truck. Of course you would have to run the engine, and also verify that it can handle the load of both winches  running at the same time. also make sure you use large gauge wire. But you probably knew all that.
Thought you would at least get a chuckle out of that.
Bruce

[MushCreek]

Being a life-long tool maker, I sketched up an adjustable stilt. It would be a heavy tube with a nut welded in the bottom, and a long enough threaded rod to come out the top. There would be a swiveling pad on the end of the threaded rod. At the top of the tube is a thick plate with holes for bolts. I could bolt it onto a stud, jack the wall up to vertical, then lower each stilt down onto the J-bolts. It's definitely overkill, but I have all of the materials, so a few pleasant hours in the shop, and I'd have a real system. I figure I'll have 6 sections of wall to tilt up, and then- I don't know- sell 'em on ebay? The house walls will be on a wooden floor deck, so I won't need the stilts.

The barn is 28' X 48'. I added it up, and the 28' walls, fully sheathed, will be about 900 lbs.; not really that much in the grand scheme of things. I wouldn't attempt the 48' walls in one piece; I'll do 24' at a time, and then splice them together with the second part of the double top plate.

[MountainDon]

Here's an idea and a drawing from my engineer friend.

The red line is a steel strap, nailed to the underside of the PT sill before the sill is placed on the block wall. One leg bent up. That bent up end is nailed to the bottom of the second bottom plate of the wall (framed and sheathed flat horizontally). Then the strap acts as a hinge when the wall is tilted up.

[MushCreek]

That's a nice, simple solution- not nearly as over-engineered as what I drew!

[MountainDon]

To add to the method explanation... (from the PE)

You can bend the bending/pivoting straps by the dozen to 90 degrees in a vice or some such, then nail them to the bottom of the PT sill plate, which is then bolted down with the A.B's (anchor bolts). The pivoting straps prevent the new wall from sliding off the PT sill pl. when you start to roll the new wall up and into place. The temp. 2x4 blkg. on the left can be short and btwn. the A.B's., and is nailed down to a string line, or the edge of the sill pl., something to push or buck the wall up against as you are building it, something to keep the 2nd sill and studs straight during framing and while applying the sheathing.

Note that a few toenails through the 2nd sill pl. (on edge) into the PT sill pl. to hold it in place will just bend or pull out when you tilt the wall up. Then the 2x4 gets removed just before you tip the wall up, so you can drill the 2nd sill pl. to miss the A.B's. and washers, and possibly drive the lowest nails through the 2nd sill pl. into the stud ends. Then the wall is just tipped or rolled up about the pivot point, it rolls into place, doesn't fall into place.

Walls like this may weight 40 or 50#/ft. of length, but you are only lifting half of this at the top pl., as you start to roll the wall up. And, you may want to have some diagonal kickers ready to install to brace the wall before you start rolling it up and into place and plumb. The 2nd sill pl. can then be nailed or screwed (not deck screws, rather structural screws) down to the PT sill pl.

The PT sill pl. must be bolted down when you tilt the wall up. They do make special A.B. coupling nuts, such that you could remove the nut, install the coupling nut in its place, install an extension rod, then a 3x3 washer (Simpson BPS or BP bearing pls.) and a regular washer and the nut. Use special nails and hardware in contact with the PT sill pl. And, depending upon bldg. loadings you may want to tension tie or shear loading strap the wall down to the found. wall.

The 2x6 temp. blkg. below and the right is just to bring your building platform level up to the same elev. as the top of the PT sill for the wall tipping operation. It's removed after the wall is rolled up and braced. Actually, no carpenter will complain about working at the height of this platform, about 32". You want to sheath the wall to keep it square, and you can tyvek it too before rolling it up. You apply the 2nd top pl. when the walls are vertical to tie them all together.