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Staking a Concrete Pad for Residential
Posted by bushaxe on November 4, 2021 at 6:49 pmIt’s been a while since I have done any kind of construction staking and I need some guidance. I have been asked to stake 4 corners of a 40’x20′ rectangular concrete pad for residential construction. Is it standard to set a hub and tack offset in each direction at each corner with a guard stake noting the offset from the corner? The site is flat. The slab is to be graded at 4-inches above the adjacent sidewalk.
DDubya replied 2 years, 5 months ago 23 Members · 36 Replies- 36 Replies
Been a while for me also. I always had the best luck by asking the “end user” of my staking exactly what it was they were needing. No need to get all persnickety if the concrete crew can pull their own string lines and square up their forms. The flip side of that is you might run into someone that has no earthly idea what they’re doing and needs someone to hold their hand.
Make a phone call or two.
I hear ya. I was contacted by the Project Manager. I’m pretty sure he has no idea what exactly is needed and is only relaying what he knows. I’m trying to put together an quote for him. If I knew what was common, I’m thinking I’ll be close enough with a little padding.
Definitely ask the contractor installing the concrete, do not guess. He will know what works best, what direction he will dig, and how concrete will be poured. Some want just 4 stakes on corners, or 4 at 10ft offsets. Some want 5t offsets. Very few will want batterboards. But make certain to ask exactly what they want pay for.
5 off and 10 off both ways at 4 corners, 16 stakes. That??s what our carpenters want but that??s in-house. One pin at finish floor elevation anywhere out of the way within view.
So here is the rest of the story. It’s three slabs on three adjacent lots that are only 33′ wide and 66′ deep. One of them is a corner lot. The slabs are 23 x 41 on two of the lots and 21×41 on the corner lot. I have 5 feet between the side property lines and the slab on two of the lots. But I only have 3 feet between the side property line and the slab on one side of the corner lot and 10 feet on the other side. 3-feet seems awfully tight. Any suggestions on what do on that side?
I prefer to just give them four corners of some distance offset from the ??big box?. Lath only if I can get away with it.
With the concrete guys around here I give them what I think they will need according to the individual job. If I ask them I’ll be there two days staking a house with four corners. Then they will want it staked in the hole, then on the footing. Hand holding all the way. They will ask for the moon because they don’t pay the bill. Its not like they don’t know what to do, they just prefer someone else do it. Biggest problem is the timing. They will call at 5 today and tell me they need it by 8 tomorrow. I don’t mind the money, but my other clients don’t appreciate being pushed back because of it and some are getting bigger bills. Heck, some of the concrete guys around here have better equipment to do the job than I do.
And then they lie about. Had one tell me the City wouldn’t let them continue unless I staked it in the hole. I called the City and they had no clue what I was talking about. That really yanks my chain.
MikeI hear what you saying. Here is the question I asked yesterday and the response I got. It sounds like I am making a bigger deal out of it than I need to. Maybe they just want lath at the corners of the slab?
“2. Did you say you only needed the 4 corners of the slabs staked? I think that would be fine since there are only a couple of “bump outs”. Please confirm with your construction guys. Also, the offsets for each corner are going to be a little tight since the lots are so small, Maybe 3-Ft? yes, the exterior property boundaries and 4 corners of slabs”
Hub & tack at the actual corners. Pull a tape to make sure everything is square. Inverse your staked point to your property line pins to ensure proper side clearance. Set a TBM at your planned finished floor elevation. Unless otherwise requested, I’ve always let the concrete crew pull off their own offsets for batter boards.
- Posted by: @leegreen
Definitely ask the contractor installing the concrete, do not guess. He will know what works best, what direction he will dig, and how concrete will be poured. Some want just 4 stakes on corners, or 4 at 10ft offsets. Some want 5t offsets. Very few will want batterboards. But make certain to ask exactly what they want pay for.
^^^^This.
Probably just the 4 corners, no offsets, presuming that you are staking on prepared ground. Make sure they are set flush – the forms will be set over the hubs. If the ground is not prepared in advance, and they don’t want you making a second trip, you will have to set offsets, the amount of offset being based on how deep they will be scraping the ground.
The concrete crews doing this type of work are going to be far less experienced than those you might find doing commercial construction. So they won’t be able to guide you. This may very well be their first experience as well.
Paint the corners and leave a height nail for the digger.
When the digout is finished either leave four offset pegs or mark the batterboards.
I’ve won contractors over with these steps.
AFTER your boundery is locked down????
Stake 5′ offsets or more with whatever cut they want, be it finish floor or subgrade or elev on lath, story board, don’t matter. Tell them once you do your dig out and rip all the stakes out, call me. Come back and hub and tack building corners when they are ready. I’ve found it works out great in my experience to set the batter boards up and nail them while I have the total station there. You get a couple of contractors spoiled on setting up their batter boards and pretty soon you won’t even have to bid???
Put a nail in range with the front of the house on the sidelines. Don’t flag it up but record it in your collector and make a note in your field book. If they screw it up you’ll have those nails to prove your original stakeout was inside the setbacks. I worked in Charlotte for a few years. I never staked any slab on grade so we always pinned the footers. National home-builders love to shoe horn a house onto a tiny lot.
For something like this I am going to set nails at each of the corners of the slab, after I survey the boundary. I might not necessarily create a plat for the boundary but I am going to make sure everything works. They are probably going to do a turn down slab so you may have to make a trip back out to pin for block/forms on the footer. I set concrete nails and store my shots at that point. Most of the home builders I work with are not concerned with getting things as tight as I try to get them.
In the thousands of houses we have laid out it was usually H&T at the four corners with a grade stake in the center. At the time we charged a lump sum per lot for house stakeout and $30/additional grade stake or an additional $120/lot average with each house box corner being graded. Made a killing on some projects that wanted the lot corners graded too. ????
Around here we always pin it in the hole. I believe the city does require it here. Some builders excavate by themselves but most have us stake it first with a cut for the USF.
The ones that stake themselves often don’t dig it far enough. I don’t understand why if they have foundations already up one or 2 lots away they can pull distances off from the plot plan, but it still happens.
Some builders have us put nails on the footings for the walls. I prefer this because the shot rock they usually use can make it almost impossible to get the nail where you want it so you can set it slightly less tight if you’re always nailing the footings.
Pins are always set at the corner of the foundation wall. The only exception to this has been setting grid-line intersections on large projects.
A couple times I have set offsets as a favor when a couple corners weren’t excavated far enough to set the pin, so we wouldn’t have to come back to do it.
It might seem ridiculous to some to put nails on the footings but a lot of these houses are built at or near the absolute minimum setback. Sometimes 1.2 meters sometimes 0.6 (2 feet!) Some pay us extra to set rebar so they don’t need us to come back.
This is a slab, right? A rectangular span of concrete with no walls? Maybe I’m missing something, but this seems like a fairly low -precision layout. Stake four corners with spikes or rebar, and they can string between those. Or hubs with nails sticking up, or 10′ offsets, or whatever. They’d have to be complete idiots to screw this up, right?
I’m confused about why we would do their job for them? We set nails at the corner of the foundation walls and the formers set their forms up around our nails. We can’t keep up with the work here as it is.
In some areas around here the municipality does require stakes in the hole, they consider it a recertification which makes no sense as nothing is there to certify, but them’s the rules. Usually I’ll just give them three corners and they’re good to go. I don’t mind this as its part of the plan and scheduled as such. Its when the concrete guys are just lazy that it honks me off. I normally wont set the house at minimums so it really isn’t that picky unless the inch guys did the layout.
There is one Village down here where I have to stake for digging, then for the footings and then again on the footings. Then I have to go back again and certify the walls. Every job, even if its many feet away from minimums. That can be a pain and nobody like the invoice after that circus.
Mike
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