Hello, my wife and I are looking to purchase a home in Texas, just north of Houston. The home was built in 2001 and is a one story home with an attached two car garage and back patio. We had an inspection on the house and the inspector notified us that the home has a pt slab foundation. And also found a couple of pt cable ends exposed. I know nothing about this type of foundation and have been searching online to inform my self a little bit more. The inspector sujested, to have the cable end clean ( remove any rust) and to seal the missing mortar with mortar caulk. We don’t know what we should do next as far as getting it checked out by some foundation company orto simply follow the inspectors sujestion. I’ve found contradicting sujestions on line, and of course every case is different. I will attach the pic from the inspection… Any input help from you guys will be greatly appreciated… Thanks in advance!!!
The inspector is correct. It should be cleaned and sealed.
Thanks for the response, is this an issue that I should worry about or need to have looked at by a professional?
Also can someone point me as to what to use to clean it with, and if it’s ok to use the mortar caulk or should I suse cement patch to seal the end off??
Cleaning in this case means removing any dirt, grease, loose grit, loose rust, mortar, etc.
Do not use caulk or mortar, as these are not the proper material for this application. The tendon end should be covered / sealed with non-shrink grout (sometimes referred to as hydraulic cement).
You want to prevent the tendon end from being exposed to moisture because capillary action will craw it into the slab between strands where it can eventually cause failure of the tendon. Do not worry about the two cut off nails at either side of the tendon, just the tendon itself.
Will this grout work?
And as far as cleaning goes : soap and water and scrub with a wire brush.
I planned on spraying rust -oleum rust inhibitor after after the cable is clean and dry. Good idea or bad?
Thanks for the replies
I would not spray anything on the tendon. You cannot get paint to the area that needs to be protected and it may interfere with the grout’s ability to bond. The product in your link is suitable for this application.
Luis, Not much of an inspection photo to see what’s there, but most likely just needs to be filled w/ a cement product. Don’t be over concerned w/ it. If it’s the pocket, tensioning end of cable, just needs to be filled for seal w/ any cement type product. Just fill it !
Here’s some post tension cable slab foundation info for review:
improperly cut or absent cap @ tendon
- The concrete cover to the tendon tail from the finished concrete foundation edge should be 1 inch.
2, In some parts of the U.S., the prevailing construction procedure has been to cut the tendon tails using an abrasive wheel cut-off saw which results in less than 1 in. of cover. For this case, the following will apply:
It is permissible to reduce the concrete cover to the tendon tail to 1/8 inch, provided that the tendon tail is covered with a protection cap or equivalent device that will result in a minimum cover of 1 in, from the face of the concrete to the exposed strand and provided that the contractor can ensure the integrity of the concrete patch material
have to go w/cevans on this one for prescribed repair
from pti const & maint manual
PATCHING OF POCKET FORMER RECESSES
1.The pocket former recesses should be filled
with concrete patch material immediately after
the tendon tails have been cut.
2.The patch material used should be non-shrink
grout that will attain the same minimum compressive
strength as the concrete foundation.
3.Prior to installing the concrete patch material,
the pocket former recesses should be cleaned
of any dirt, grit, oil or other substances so that
a good bond is attained between the concrete
and the patch material. A bonding agent can be
used to enhance bond of the patch material to
the concrete; however, it is important that the
recommended application instructions from
the bonding agent manufacturer are followed.
4.If an encapsulated system is used, the posttensioning
material supplier’s recommendations
for cutting, capping and patching should
5.Under no circumstances should the concrete
patch material used for filling the pocket former
recesses contain chlorides or other chemicals
known to be deleterious to the prestressing
6.The pocket former recesses should be completely
filled eliminating all voids and finished
to match as closely as possible the surrounding
edge of the foundation,
It’s a 14 year old pocket. You can quote- cut and paste as above, how it shoulda, coulda been filled from the start which I don’t disagree with… There’s been no issues, w/ one open pocket at an entire post tension slab after the tensioning 14 years ago… Quit making a mountain out of a mole hill. Shouldn’t be a problem. Just fill it !
Thanks for all the Info… I cleaned everything pretty good on Friday and sealed it back up Saturday morning.
Also, the ends of the cable that were exposed are the ones on the patio slab, which is connected to the house. Don’t know if that makes a difference or not.
One more question, I have contemplated on doing a acid stain on the patio slab, but now sure if it’s a good idea given the pt cables being in the patio slab. Acid stain will eat up any metal… Not sure how deep the stain penetrates the concrete. I had planned on using kemiko concrete stain, but I’m hesitant about this. Maybe some one more knowledgeable can shine some light on this…
Thanks again everyone!!!
The stain penetrates about 1/8" max. The cables should be deeper than that. I doubt it would be an issue.
Im with Frank
There are some hair line cracks on this patio slab that range from 10-20 inches.and there’s a huge one that runs more than half way in the middle of the slab. I’m concerned that the stain will seep through the cracks and penetrate further and thus causing problems. Any thoughts on this?
This is the over all pic of the 200 sq ft patio.
Now the smaller craks are what seem to be hair line craks. The bigger one has both hair line cracks and in some spots some bits of concrete has come off over time I assume, those range from 1/4, 1/8 wide and less than an inch long.
Any in put would would be greatly appreciated…
Guess I better not go through with the stain… Better safe than sorry…
The tendons have a heavy plastic sheathing that protects them
There have been many posts over the years related to this topic…
Search … Jeff Pope Tension and
Ron Huffman P.E.