Residential Foundation Layout

Has anyone used the RS+ for residential foundation layouts and for pinning footings. Just wondering about ease of use, and if anyone has any layout examples. Thank you

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I wouldn’t think pinning the foundation is accurate enough. Using the RS+ for laying out the foundation is fine for excavation… make sure you have a “fixed” solution on every point and verify by taping or use a robot/total station. I would be awful cautious using for the “pinning” of the building corners for the brick masons. However, I don’t think using the RS+ for pinning has the accuracy you need. I’d hate to see you have to pay for re-excavation and re-pouring for concrete.

Use a robot/total station for the “pinning”. We always use this combination for staking of the foundation and pinning. The accuracies required by the builder/brick masons here in this area is usually 1/2" (0.04’) or (1.5 cm).

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I think in some parts of MS and LA tolerance is plus or minus 1 foot. ; )

Seems typical is a tenth of a foot (maybe 20+ years ago?) which I would ASSuME would be sufficient if so? Maybe @chascoadmin will jump in.

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Emlid Reach RS+

Positioning

  • Static horizontal 5 mm + 1 ppm
  • Static vertical 10 mm + 2 ppm
  • Kinematic horizontal 7 mm + 1 ppm
  • Kinematic vertical 14 mm + 2 ppm

STATIC 5mm = 0.5 cm = 0.19685 inch = 0.0164042 foot.

KINEMATIC 7mm = 0.7 cm = 0.275591 inch = 0.0229659 foot.

But I guess this is perfect lab conditions?

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Depending on your building tolerance required, I’d heed that warning from this professional registered land surveyor. ; )

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Yes, building tolerances can get ridiculous at times. We just finished a complicated foundation that required a 5mm (0.016ft) tolerance so obviously we couldn’t use GPS. Millimeter-GPS isn’t even that close.

The reasoning was that finish was primarily stained concrete but there were allot of lowered (sunken) areas designed for tile and VCT to be layed in flush with the concrete. A more typical tolerance on building (foundation) tolerance is 0.05ft.

For everything else the tolerance is 0.10ft but the crews are responsible for pulling their own offsets for verification and setting their alignments with theodolites.

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We’ve had clients come to us for pinning the foundation for the brick masons after the foundation has been excavated and poured with concrete. This was done by non-professional people.

Guess what… The foundation dimensions don’t match on the ground. Clients try to save money on a $500k house. Ridiculous !

I tell builders and future homeowners we need to stake the foundation and pin for brickmasons. Usually our fee, depending on the complexity of the house or building plans is a minimum of $1600 for each staking.

Last client had to tear out the concrete foundation.

Boy he really was saving money !!

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Hi there,

Reach RS+ can provide you with centimeter-accurate coordinates in RTK and PPK.

Tim shared the correct info about the Reach RS+ positioning accuracy. You can always check it on the Reach RS+ landing page on our website.

PPM shows how the relative accuracy rises with each 1 km of baseline. For example, Reach RS+ provides 7 mm + 1 ppm in horizontal in RTK. If you have a 2 km baseline, your final horizontal accuracy will be 7mm + 2*1mm = 9mm.

However, please note that Reach RS+ is a single-band receiver. So it requires a clear sky view and baseline up to 10 km to provide centimeter-level accuracy.

For the rest, there should be no issues with using Reach RS+ to get precise coordinates.

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