post tension foundation

[aschen]

I think my house has a post tension foundation. I can see the grout marks on one side. My maxjax is in transit to me and I will need to drill for anchors. Does anybody know much about these? Will it be straightforwards to call somebody out to mark the locations of the cables? I know I DONOT want to hit one.

I can see the location of where they were tensioned on one side of the house. However that is on the distant end from the garage, I dont want to take a leap of faith that the run exactly parallel to the front of the house.


Thanks

[javadog]

About all you can do is locate the holes on all four sides and try to diagram out where they are. They are generally laid in pretty straight lines, assuming your contractor wasn't an idiot. You might try to locate them magnetically but that may be difficult, especially if they installed rebar or mesh as well as the cables.

[derek murray]

Any chance the grout marks you see are covering the form tie locations, and not tensioners?

[E38Driver]

Can you check with the building dept? Also usually there is a stamp that they put in the slab in the garage floor.

Dave

[aschen]

Originally Posted by derek murray

Any chance the grout marks you see are covering the form tie locations, and not tensioners?

hmn not sure, maybe that is why I only see them on one side. I think I may have to bite the bullet and pay a pro

[aschen]

Originally Posted by javadog

About all you can do is locate the holes on all four sides and try to diagram out where they are. They are generally laid in pretty straight lines, assuming your contractor wasn't an idiot. You might try to locate them magnetically but that may be difficult, especially if they installed rebar or mesh as well as the cables.

apparently there are some fancy radar imaging tools. I am a little confused why I cant see holes on the garage side of the house. I thought they may be below grade or anchored below the concrete surface

[Tobra]

There was a builder in the Kingwood area that really half assed the foundations leading to the bankruptcy of the insurer and a bunch of people with houses that were worth less than what it would cost to repair them. Don't recall his name, hopefully not the issue you are dealing with.

[chapo]

Only safe way is to have it x rayed. It's not that expensive, just mark out the area you want done. You don't need to do the whole garage. We do it all the time for additions and remodels.

[vash]

they wont be parallel to the foundation..it should dip in the middle and taper up at the ends..to adjust for the compression and tension portion of the "beam". that's how i have seen it done.

what is a maxjax?

[vash]

oh..and the cable ends i see are usually a cap type..it wont just be a grout spot..there is an actual cap they come and grout after the fact.

[JavaBrewer]

Originally Posted by chapo

only safe way is to have it x rayed. It's not that expensive, just mark out the area you want done. You don't need to do the whole garage. We do it all the time for additions and remodels.

+1

[aschen]

Originally Posted by vash

what is a maxjax?

Small 2 post lift for residential garages

https://www.maxjaxusa.com

[vash]

oh..this is a slab foundation? not a perimeter type?

and that maxjax is badass.

[aschen]

Originally Posted by chapo

Only safe way is to have it x rayed. It's not that expensive, just mark out the area you want done. You don't need to do the whole garage. We do it all the time for additions and remodels.

Yeah thanks i think i need a pro

I need to do a bit of research for confirmation that it is post tentioned forst i think

[vash]

i never seen a tension slab before..i had to google it to satisfy my curiosity. pretty cool..ignore my post..it is a much different system.

apparently there should be a stamped warning..no? usually in a corner of the garage. that's what the article said..

very cool system.

[rwest]

Can you get below it? I think that is the only way the x-ray works.

Had it done at work for a mezzanine fence-super cool, they had a small canister with a tube and then a long cable with a crank on it. The radioactive piece (size of a pencil lead tip) would get cranked up the tube to the underside of the floor and the film was on top. Then it got cranked back down to the canister. I think 4 exposures developed and everything was $600 or so.

[908/930]

If it is near the surface Bosch makes a reasonably priced tool that will pick up rebar to about 4 inch depth, I used them in the past and was quite impressed. Approx $250 for the entry one D-Tect 120. Possibly can rent one.