Pinning Foundation Walls or Marking ConcretePosted by murphy on July 13, 2019 at 2:08 pm
I don’t do much staking, but occasionally I’ll stakeout footings and then pin the exterior concrete walls.
I get my desired accuracy with a Leica GMP101 but I’m having trouble finding an efficient way of marking precise points in the concrete footing. To date I’ve experimented with various types of masonry nails. Most of the time it works okay, but I always get a few nails that wander, bend, or just don’t go where I need them to go.
Has anyone tried using a hammer drill and something like a tapcon screw to pin foundation walls?
Any other ways to quickly and accurately place permanent marks on concrete?
- 12 Replies
- MemberJuly 13, 2019 at 2:43 pm
I’ve pinned many footings over the years and you will almost always land a point or two on a piece of aggregate. The common masonry nails available in most hardware stores work pretty well. Mags or PK’s are stronger, but can get expensive if you do a lot of footings or there are many corners on a particular job. I usually use the 1 1/4″ fluted masonry nail. It’s long enough to hold between the fingers, but not too long ( bends easier). You may have to sacrifice 2 or 3 nails before the point finally holds, but at $5 a box, who cares? The other important thing is to get to the site the day after the footing is poured while the concrete is still ‘green’. Makes for a world of difference…
- MemberJuly 13, 2019 at 7:55 pm
Robot and Hilti gun is by far the fastest way to set masonry points. On a 20 point house you might have to fine adjust 1 or 2. I use a cold chisel for adjusting. Observe an average masonry crew set up boards and string lines, you’ll find that a hundredth or two isn’t as important as we think.
- MemberJuly 13, 2019 at 10:08 pm
I have always preferred a yellow paintstick and a #2 pencil for marking points on concrete.
If you use a drill, a rock drill is best and will drill better and faster than a hammer drill.
- MemberJuly 13, 2019 at 10:45 pm
I have used nails found in your local big box store in the carpet section….come in two lengths I believe…they go into the concrete footers real easy….Ronald W. Berry
- MemberJuly 14, 2019 at 1:17 am
A scribe and a straight edge to mark an “X”. Go over the scribe with a red pencil, then circle scribe with paint.
I carry a torpedo level in my vest to use as a straight edge (among other uses.) And in the truck is a Dewalt cordless grinder in case the concrete isn’t smooth enough for a scribe.
- MemberJuly 14, 2019 at 11:06 am
Thanks for the replies.
I’ll try a scribe next time.
Between dealing with the contractor’s schedule and evolving blueprints, I never feel like I come out ahead on a foundation stakeout. I had one guy who was giving me grief over an 1/8in despite providing me blueprints with dimensions that missed by 3/4in.
- MemberJuly 14, 2019 at 1:46 pm
If it is live and direct just red pencil and clear coat can get her done sometimes. For scribing I am partial to the tile scoring knife
For masonry nails I am partial to the 3/4″ mag with a 5/32 bit on the rotary hammer.
I like the grinder idea above, will have to throw that in the line up.
- MemberJuly 14, 2019 at 6:59 pm
Ive been pinning a lot of footings over the years. Depending on the accuracy you need to obtain, I have been using a Ramset and getting great results. you do hit the occasional rock that throws your nail off but I always do a check shot after it is set and as long as your shot it in straight it goes where you want it. I have been pinning town home footings for a block wall so there is a little room for play. We generally keep it to a 1/8″. Don’t use the ramset type that you have to use the rubber end piece and hit it with a hammer to set the charge off. Spend the money and get the gun type or one with a trigger.
You also have to take inconsideration the age of the concrete also. If its try for a couple days you don’t need a strong caliber. The gun I have you can actually adjust the strength of shot. All in all if you setting 70 points per building and pinning two or three a day the ramset has increased production substantially.
- MemberJuly 14, 2019 at 8:55 pm
I heard the Ramset and Hilti can’t be used in NY area due to gun laws. Since these fire a projectile from gun powder cartridge, and barrel, they require a pistol permit. Not sure how true this is. But I have not seen one used in a few years. They now drill holes with rick drill and pound in nail.
- MemberJuly 15, 2019 at 8:56 am
I’ll second the suggestion to use a red pencil and clear paint, and add knee pads. One summer I did a lot of this for a townhouse project. Kneeling on concrete is OK once in a while, but keep at it and it catches up to you and is painful. Seriously consider knee pads.
- MemberJuly 15, 2019 at 2:15 pm
Dewalt lightweight hammer drill and form nails painted fluorescent pink. ????
- MemberJuly 16, 2019 at 12:39 am
I have used a hammer Hilti drill with a slightly smaller diameter bit than the PK nail. This lets you set an accurate, tight point. If you are tapping to the thousandths then I would recommend using a larger bit than the nail and using Hilti resin (ice) or Dywidag glue, to glue and manipulate the nail into the right place.
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