Raising walls on a concrete slab

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Forum topic by Derakon posted 01-30-2015 03:20 AM 3231 views 0 times favorited 20 replies Add to Favorites Watch
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89 posts in 1586 days

01-30-2015 03:20 AM

Topic tags/keywords: workshop construction wall question

I’m working on building my first workshop (no more working out of a cramped 1-car garage for me!), and recently got the slab foundation put in. Now I need to figure out how I’m going to go about raising the walls. I’m working alone (unless it turns out I really need to hire help). The walls are in 8-foot sections, and they’re built out of 2×6s. They’ll be secured directly to the slab using anchor bolts (3 bolts per 8’ section), no tiedowns, straps, etc.

I figure I can get a couple of wall jacks for lifting the walls, which takes care of the physical lifting. I can’t secure the jacks directly to the concrete foundation, of course, but I could build a cross-braced framework that runs out to the nearest edge of the foundation and hooks onto the anchor bolts there, and then secure the jacks to that.

What I’m confused about is how I’m going to get the bottom of the wall to fit onto the anchor bolts that will hold them to the slab. If I start out with the sole plate up against the bolts:

then when I start lifting, all the weight of the wall will rest on the top of the anchor bolt, which I expect would then bend. So that’s no good.

I could maybe rest the sole plate on some blocks, prior to the lift. Basically trying to line things up so that the tilting action from the wall jacks will line the holes in the sole plate up with the anchor bolts:

I’d be a little worried that there’d be some slipping during the lift, but maybe it’s not a problem. And I’d also have to make certain that the wall doesn’t end up resting on top of the blocks. That can probably be solved with a mallet and/or prybar though.

Of course, I could also just build the wall in its upright form, toenailing the studs in. But I’d rather build flat if possible, so that I can get the wall squared up and sheathed before it gets lifted into place. If nothing else, it’d save me from having to put all that plywood on while it’s vertical! I’ve never done construction on this scale before, so the fewer factors I have to deal with at one time, the better. Especially since dumb ol’ me decided to spec 3/4”-thick plywood as part of my decision to overbuild this thing.

Anyway, any advice would be appreciated, even if it’s just “hire someone to help you, you idiot”. :)

20 replies so far

View rustfever's profile


716 posts in 2729 days

#1 posted 01-30-2015 04:15 AM

Build the wall flat on the floor. Lift the wall, using levers or friends and kickers to keep from toppling. Position and align. Then drill the sole plate AND the concrete. Install epoxy or wedge anchors of the proper size/length.

-- Rustfever, Central California

View Andre's profile


992 posts in 1225 days

#2 posted 01-30-2015 04:46 AM

My shop had 24’ walls 10’ high 2”x6” and sheeted 3/8” ply. Three of us stood up the 1st. wall put ended up needing 3 more guys to stand and place last 3 walls. Had to lift walls up and place on preset anchors. Get lots of help, worth the cost of beer and burgers.

-- Lifting one end of the plank.

View splatman's profile


542 posts in 818 days

#3 posted 01-30-2015 05:02 AM

Are the anchor bolts already in place? if not, Rustfever has the right idea. Once the walls are where they go, fasten them down with concrete bolts.
Applying the sheathing before tilting up, is the way to go. Houses are built that way all the time. Prop up the top edge with 2×4 scraps before applying the sheathing. Better: Also install the windows, felt/housewrap, and siding. Shure, that makes the walls real heavy, but if you’re using wall jacks, that might be a non-issue. Or just get as many helpers as you can. You’ll be thankful you did. I built a shed that way last summer. Hard at first, but saved a load of gravity-induced frustration later.

View Smitty_Cabinetshop's profile


13569 posts in 2037 days

#4 posted 01-30-2015 05:08 AM

Put a pressure treated sill down over the bolts first. Counter boar the top of the 2x so nuts are recessed. Anchor, cut excess bolt lengths flush. Stand up wall on top of that sill, nail.

That’s one way.

EDIT: Ghidrah has a much more detailed answer that is much, much better than mine. Especially considering I re-read the OP and see 3/4” plywood sheeting is in play. Holy cow, that’s gonna be heavy, heavy stuff.

-- Don't anthropomorphize your handplanes. They hate it when you do that. -- OldTools Archive --

View Ghidrah's profile


667 posts in 641 days

#5 posted 01-30-2015 05:10 AM

1st snap a line where the plate will sit on the slab, lay your PT sill against the found bolts and mark the sill at each bolt. Meas from the line in to the center of the bolt and mark it off on the sill. Bore the holes in the sill. Not knowing where you live you may be required to apply insect guard to the base of the sill and you may be reuired to seal the bottom of the sill with PL200.

Set the sill on the line and bolt the sill in place. Let it set for a day to ensure it sets, (it is temp relative). Once you have your sills in place you can remove the bolts, I do suggest you shoot the sill with concrete nails to reinforce the sill, efficacy is dependent on the sure of the concrete. Then snap a line on the sill where the bott plate will sit and repeat your previous work minus setting the bott plate. Drill the holes twice the bolt diam.

Go to the Lumb Yd and get some of the pallet banding. Drill the banding and nail it to the bott of the bott plate every 48”. Lay out the plates, toenail the bott plate on the sill line and assemble the wall minus the plywood. ensure the bott plate is secure then screw the pallet band to the inside 1 1/2” edge of the sill.

Diag the wall, pin the top plate then lay the bottom course of ply only, (makes it bott heavy). Pop the top plate pins set the top plate on some 2X4 to provide a space for hands or to attach the jacks.

If you aren’t versed using jacks and or wall framing I highly suggest you get backs and muscle to help you, extra hands may save your life and or damage to the wall or property.

I also suggest you prep your wall braces ahead of time by pounding stakes into the ground to nail the braces off during wall plumb, you don’t want to be flopping around when the wall is standing.

P.S. you want to bolt the bott plate to the sill and found so don’t waste the time recessing the sill holes and remember to remove the bolts before you raise the wall.

-- I meant to do that!

View runswithscissors's profile


2127 posts in 1444 days

#6 posted 01-30-2015 06:35 AM

I like setting the wall up first, then drilling through the wood (with a wood boring bit), then into the concrete with a hammer gun /rotary hammer (the cheap ones from Grizzly or HF work fine for this). Drive in expanding bolts, attach washers and nuts. You can also epoxy them in as suggested above.

-- I admit to being an adrenaline junky; fortunately, I'm very easily frightened

View Derakon's profile


89 posts in 1586 days

#7 posted 01-30-2015 06:55 AM

Holy cow, I leave for three hours and there’s tons of suggestions already. I know it’s been said before many times, but this community rocks. :)

The anchor bolts are already set in the concrete (they were wet set). I’m not entirely certain I understand Ghidrah’s instructions, but it sounds like you’re saying to effectively glue (liquid nails) the PT boards to the concrete, cut the bolts off, and then set another row of boards on top of that that the wall will go on? The plans I’m using (and for which I got the construction permit) have a single set of 2×6s as the sole plate/sill/what have you, that the wall studs are directly connected to. So if I were to go with your approach, I’d need to modify the plans and get signoff on them. I mean, that’s not the end of the world, but I’d rather avoid it if possible. Especially since I’m butting up against the limits on allowed building height as it is.

The plans are here though there are some minor modifications and added details as specified by the planning office. Mostly just changes to the sizes of nails and the like, and moving the sheathing 2” higher.

It does sound like I should probably get some extra hands for the walls. As mentioned before I haven’t done any serious construction work before, so no, I have no experience with wall jacks. I’ve read up on the subject, but that’s no substitute for getting your hands dirty. I have 10 wall sections to do total…guessing that’s probably more than one day’s work. :)

View JeffP's profile


573 posts in 811 days

#8 posted 01-30-2015 11:47 AM

This is probably worth precisely the same amount you’re paying for it, but maybe it will give you some ideas to play with:

Basic idea: use some pivoting 2X4’s (attached near the top of the wall) and a pickup truck to do the heavy lifting of getting the wall mostly vertical—manually set it in place on anchors one end at a time.

1) start with wall laying flat on concrete, well AWAY from your anchors
2) put some 2X10 or larger spacers between the sill plate of your wall and each of the anchors and slide the wall up to snug them against the anchors
3) Attach some temporary 2X4 “legs” near the top of the two end studs (should be a couple feet longer than the wall is tall) using a single LARGE decking screw, so it can rotate/pivot outwards to eventually be a temporary angled leg to hold the wall up while you wrestle it into place
4) lift the top end of the wall up and put some cinder blocks or something under it to hold the top end up about 2 feet off the ground.
5) attach a 2X10 stringer across your pivoting legs near the bottom with decking screws
6) lift your stringer up and tie a rope between the center of the stringer and the trailer hitch on your truck with only about 1 foot of slack.
7) pull the truck away from the slab very slowly using the the “leg” assembly as a stiff tow line to pull it up to almost vertical
8) put some pivoting “legs” on the “inside” so the wall can’t fall over
9) unhook the truck
10) manually finish sitting it up vertical and set the temporary legs appropriately on both sides
11) manually lift the wall up and set one end of it into place on its anchor
12) repeat on the other end
13) have a beer
14) rinse and repeat

-- Last week I finally got my $*i# together. Unfortunately, it was in my shop, so I will probably never find it again.

View Ghidrah's profile


667 posts in 641 days

#9 posted 01-30-2015 07:53 PM


It’s very possible your town hasn’t adopted the newest version of the code yet and or a local variance is in place not requiring a PT sill, sill seal or insect guard. It appears they’re allowing you to use the PT as sill and bottom/sole plate. Regardless of the excess length of the H bolts don’t bother cutting them; they won’t affect the R value of the insulation or interfere with the electricals.

Previously, it was late and my brain skimmed over (walls in 8’ sections), that’s a 2 man job, save the money on the jack rental, pallet banding and concrete nails. I didn’t see any mention of how high the slab is above grade or how long the entire wall is. The IRC requires 7” between grade and wood.

I’d frame and square the 4/8’ load bearing corner sections and set the bottom sheet of ply then stand and brace them. I’d then frame and stand the middle sections minus the ply and secure them to the corner sections and attach diagonals to the middle sections and brace them off to ground or slab.

1. You need to check the slab to ensure it is or isn’t square. If not I suggest snapping parallel sill lines on the load bearing sides of the foundation ensuring no part of the foundation protrudes past the exterior side of the sill. You can do this by taking to sections of your (sole plate) and run a chalk line or string along the outer edge of the slab. Adjust the SPs to ensure no part of the slab protrudes past the line; it will prevent proper attachment and seal of the sheathing down the road.

Then before you remove the SP sections mark the slab at the inside portion of the SPs and snap a line the length of the wall. Parallel off the struck line to the opposite load bearing edge of the slab. Repeat the previous task and you have 2 parallel lines. You can then diagonal the 2 gable walls off the parallel lines using the 6’X8’ = 10’ method or multiples of it. You want to do this before you cut and assemble the walls, if you don’t and the slab is out of square it’ll wreak havoc down the road when nothing fits correctly like plywood, rafters and trim.

Once you’re ready to stand a wall apply the PL within the sill line, stand lift and lower the wall section over the bolts line it up with the sill lines then secure the bolts. If the hurricane bolts were set wet, odds are they’re J bolts, in my area the bolts are set high enough for double sills on common foundations.

PL200 and 400 are construction adhesives used to seal the bottom plates to the deck of a house or slab to eliminate drafts and as an added tool in securing the walls to the deck and foundation. If your area is prone to insect damage, (termites and C ants) you may consider “Coppertop” insect guard you will not be required to get a sign off at your Building Dept for it or PL use only the foot print and or structural/weather tight integrity.

-- I meant to do that!

View Derakon's profile


89 posts in 1586 days

#10 posted 01-30-2015 08:35 PM

Ghidrah: the slab is at least 6” above grade at all points, which is per local code as of last year at least. I think it’s actually a bit taller, which is kind of irritating since I’d specced 6” and I’m only 2” below the max building height. Maybe the planning department can cut me a break, though.

Good call on checking squareness. In theory the contractors made a square foundation (and they say they did, of course), but “trust, but verify” is the rule of the day here.

I wasn’t familiar with PL, but it makes sense; sounds like basically a caulk-equivalent for sealing gaps between wood and concrete. I’m not planning to make this workshop into “habitable” space (with insulation, air conditioning, etc.) but that’s no reason to make a drafty building.

The bolts are J bolts, yeah.

From my understanding of your recommended procedure, it’s basically:

  • Build the corner walls flat on the slab (for a 16’x24’ shop that means everything but the center sections of the long walls)
  • Square the walls, apply 1 sheet of plywood to each (sheathing the bottom half of each section)
  • Lift wall into place, brace, repeat with other wall for that corner
  • Add continuous top plate and temporary diagonal braces to hold two corner sections together
  • Build and lift middle sections into place; complete top plate, brace

After this point, to get rid of the braces I’d need to ensure the building can stand on its own. Obviously the second half of the sheathing will help with that, but I’m guessing I’ll want at least some of the ceiling joists as well.

The braces themselves are just (2×2?) stakes driven into the ground, nailed to 2×4s, which are nailed to the wall studs, right?

I’m trying to figure out how much work I can do ahead of time, so that when I hire people (or bring friends in), we don’t waste time. Ideally I’d have all of the wall sections built and ready to be lifted and braced…though I’m not sure where I’d store them all! Only so much room on the slab itself…

By my calculations, a single wall section (2×6s, with sole plate, single top plate, no rough openings, and 1 sheet of 3/4” plywood) would weigh a bit over 200 pounds…hm, that’s actually lighter than I thought it’d be. Yeah, okay, this sounds doable! Maybe I can stage the wall sections off to the side of the shop, on blocks so they don’t sit in water. Then bring people in, we carry a section over to the slab, tilt it upright and onto the anchor bolts, brace it, repeat.

Regarding insects, fortunately I don’t live in a very buggy part of the world. Termites are potentially an issue, but I don’t believe the code specifically addresses them. Still worth considering adding a treatment anyway.

Thanks very much for your advice!

View Hermit's profile


36 posts in 744 days

#11 posted 01-30-2015 09:47 PM

You can take a look at my foundation. I hope to start framing this spring.

My recommendations would be…
1) Make sure all anchor bolts are clean. Wire brush all bolt threads and make sure nuts go on easy. This will make it easy when standing the walls.

2) Drill all your bottom plates out for anchor bolts using pressure treated wood. Lay your bottom plate on top of the anchor bolts flush with the outside (using a speed square or straight edge) Tap directly over the anchor bolts with a hammer. This will mark bolt locations. Flip them over and drill. Check that they fit so you don’t fight it when raising the wall. Run the bottom plate through door openings for stability when standing the walls. They can be cut out with a saw (Blade set to 1-1/2”) before your trimmers are installed.

3) Cut top plates the same size as your bottom plates. Tack the two pieces together with 2- 8d nails. Stand the two pieces up on edge and lay in place so you can lay out both pieces at the same time. Remember to pull your 16” o/c layout from the same direction. Don’t just start on one wall and work your way around. East and west walls are layed out back to front and north to south walls are layed out the same.

4) I personally wouldn’t put your plywood on until after you raise and plum all walls, and your double top plates are nailed off. They will be wet and heavy, especially your window walls with the headers. If your slab is so much as an 1/8th out of level from front to back or side to side, then your walls wont be plum if you install your plywood before raising them.

5) Once all the walls are standing plumb/level and braced off you can start the plywood. You can install on the inside of the building a brace from the top of a stud on one side to the bottom of a stud on the opposite side. This will allow you to remove a brace on the outside so it’s not in the way of the plywood install. Work your way around adding and removing braces, nailing off the plywood as you go to provide shear.

6) Now to answer your question, you’re going to need help! At least one strong person anyway. I would Frame your two short walls first on the slab and then raise, anchor and brace them. Frame/raise each long wall on the slab separately. I’m not one for moving walls around unless absolutely necessary.

I have always shoved the bottom plates right against the anchors when ready to lift. Stand the wall up on top of the anchor bolts and they will be real close to the holes. You can lift and slide a little until they drop over the bolts. Don’t worry, you wont break or bend the bolts.

-- Sawdust? You mean man Glitter!!!

View Buckethead's profile


3140 posts in 1288 days

#12 posted 01-30-2015 10:17 PM

In my younger days I framed a 6000 sq ft duplex by myself by laying out, then securing bottom plates first, match top plates, then nailing each stud in place onto the bottom plate, using the truest studs at the corners, plumbing the corners, then securing the top plate and double plate from a ladder. I had the wall framing done (sans window and door framing but including headers and cripples/Jack studs) in three days (I also left off any interior, non bearing walls less than 10’ long for after roof was done). I had help for setting trusses and framing the roof.

This is a surprisingly efficient means of framing. It allows for minimal handling of materials in that you pick up a piece, then nail it in place. Stick framing and box framing will have you handling material more often, plus, you need help.

That said, it isn’t difficult to stand an 8’ section of 8’ tall box framed wall by yourself. The difficulty is in getting it on the anchor bolts, and securing it in place without help.

There’s a couple tricks for that, but in my opinion might be unsafe for those who haven’t don’t frame often.

-- Support woodworking hand models. Buy me a sawstop.

View Derakon's profile


89 posts in 1586 days

#13 posted 01-30-2015 10:31 PM

Hermit: that’s a nice-looking foundation! Good luck with the framing work! Thanks for the advice.

Regarding levelness and when to install plywood, I should check how level the slab is while I’m checking how square it is. Levelness was only assured by scraping a 2×4 across the framing during the concrete pour; while the frame should have been square and level, it could of course be slightly off.

Not being able to install plywood until after the wall is raised would make getting the wall squared up a lot harder, wouldn’t it? Not impossible (I have a book that describes some techniques, mostly involving turnbuckles), but more difficult.

Buckethead: I’m guessing you toenailed your studs in? Again you’re stuck doing squareness/plumbness while the wall is vertical, but I do admit there’s some attraction to not having to lift a massive, heavy construction into a precise position all at once.

View Hermit's profile


36 posts in 744 days

#14 posted 01-30-2015 10:56 PM

Derakon, You’ll be leveling the walls (in and out) with your bracing when you stand the walls. You can buy some simpson wall braces that nail to the studs on a 45 degree angle from bottom plate to top plate to plumb them. Takes 2 people. One to rack/hold the wall plumb while the other guy/gal nails off the brace to hold it plumb. You cant plumb it with plywood attached because it cant be racked.

To edit: skip the simpson brace, run another brace parallel with the wall to hold it plumb until the plywood is nailed off. Providing you have the room for the brace. Simpson strap/brace is the easier method.

-- Sawdust? You mean man Glitter!!!

View Derakon's profile


89 posts in 1586 days

#15 posted 01-30-2015 10:59 PM

Serious question: then why do so many people recommend applying plywood while the wall is on the ground? I mean, I see what you’re saying, that a wall could be tilted if the slab is not level. Do most people just not consider the minor irregularity to be worth the added complication of only being able to apply plywood once the wall is vertical?

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