> [sarcasm]I use GPS to set anchor bolts as well...never had a problem[/sarcasm]
Why the sarcasm.
I was once brought in to QA/QC a project where the contractor was having problems with the anchor bolts. After I as-built them I called the lay-out surveyor to discuss the situation and he said: "I don't see how there could be any problem, our initialization was hot"
The site
I would never trust GPS for building stakeout either, but you’re comparing apples to oranges. The errors in that report are in absolute position. When using GPS for stakeout we are concerned with relative errors, which would be much smaller given the same observation time.
I could be wrong, but I inferred that rtk would be the method employed, not static or fast static observations. If that were the case there is no point discussing GPS vs conventional in my opinion.
Are you kidding me?
If a surveyor had ANY understanding of the accuracies possible with GPS, they would disregard this subject as being totally irresponsible and non-professional.
Did you make a serious evaluation of the issue and then decide it was OK?
WHAT ARE YOU THINKING??????
Never
ALL the time. Of course it depends, which is a word I'm very familiar with (getting up into vintage age). I may be a newbie since I've been using GPS since 91.
Pablo
For years (in southern California) we set 20 and 80 off front property line on the side line and the contractor laid the house in from there. Then around 2000 they started needing a 5' o/s to the front bldg envelope and another on the long side of the house to square off. We always set un-tacked hubs to the nearest tenth and called it good. Same number of points same accuracy budgeted for 50 lots a day and all was good. Nothing a good rtk system can't do with a conscientious operator. Never had any problems except when they would flip flop a house or change a floor plan and the information never made it to the field, but that had nothing to do with equipment but it cost us more than a hub ever being off .06' did. My 2 cents, Jp
GPS for staking single family homes??????
All day....e'ry day.
Its a residential building pad not the space shuttle. We have used RTK with new R8 rovers and have hit harn points within .001 now I understand that you wont get that accuracy every time but with common sense and tape checks you will be just fine.
For the contractors willing to pay the right price, we set every stake for footing and every pin for form with the total station and check them with the total station set on a different point (usually one of the pins we set, BS another pin and shoot every point)
For the el cheapo contractors we set the building more than 1' from the setback and we use GPS (RTK) to set stakes without nails at ever corner, then give them two stakes with nails. These are checked for distance with a steel tape. We will not set pins for forms in this case, but the cheap contractor will not pay for it anyhow.
After the pour, we have found the GPS set foundation to be off by a little, but certainly less than the amount we'd expect if the contractors did the work themselves.
Similar: I have a good friend in the concrete industry. He recommends us because our pins are always within 0.02' and usually within 0.01'. He says the points he gets from other surveyors are all over the place, usually out 0.05' or more. How close do you set your pins?
Not meaning to pirate anything. If you want to use RTK and you can confidently set within 0.05' and that is the standard in the area, then you are covered.
The post is entitled "Setting house building corners with GPS". "Pad corners" is a magnitude of order different...
"Setting house building corners with GPS".
Don't do it, you will eventually have problems. Conventional is far quicker and more accurate.
Good Point Jim
> The post is entitled "Setting house building corners with GPS". "Pad corners" is a magnitude of order different...
I have set tons of building corner (stakes) by just pacing, or even just by eyeballing the lines.
"... but with common sense and tape checks you will be just fine."
Many, many of my competitors have neither of these...
Not this pup. It is not accurate enough nor is repeatability there.:bad:
Why do you think the people that
MAKE this stuff only state that RTK's accuracies are to 2 centimeters. Believe me, if they COULD state that their stuff can attain 0.02' repeatibility they WOULD. You can go out there and set a Hub and tack and then re-initialize and re-observe that point and be within +/- 0.02' every time....for about one hour. Come back six hours later, shoot that point again and you will be out at least 0.06'. That's on a good day. The further you are away from your base, the worse it gets. There is nothing more accurate than a T-2 and a calibrated 100' Lufkin Super Hiway chrome-plated steel tape, a chain tension and a thermometer.
Charlie,
If its working for you and your like your checks, go for it. If you want, email me and I'll send you a little test report that I did five years ago on this subject.
Dave
dtlusty@co.langlade.wi.us
Why do you think the people that
There is nothing more accurate than a T-2 and a calibrated 100' Lufkin Super Hiway chrome-plated steel tape, a chain tension and a thermometer.
Just plumb bobs and chain tape can prove any rectangle to less than 0.01' all the time when properly applied. Used a T-2 to close many traverses. Typical per angle adjustments of less than a half second. Ran over 9 miles once with T-2 and 300' chain tape and hit within a foot and a half.
Skill with simple tools is better than high tech wizband in some applications, in others the wizbang can improve things. Redundant proofs are required regardless the tools for any honest certification.
As builted a house once that was an inch out of square.
Next thing you know everyone was lawyered up and ready for battle.
I highly doubt that the original post meant the same observation times.
