Emmanuel May/ 3/ 2017 | 0
With all of the new construction occurring this question has been occurring more and more lately on various bulletin boards (BB) I frequent. On one very popular BB there appears to be a concrete contractor (foundation contractor) doing a good job of convincing unsuspecting new home buyer not to have a foundation pre-pour inspection performed on their new homes (pre-pour is before concrete is poured for the foundation). The contractor also convinced another unsuspecting home buyer not to have a licensed Professional Engineer come to review problems they have seen on their new home foundation that was recently poured.I have inspected many new homes, including pre-pour inspections, and dealt with many contractors. Only those Builders and contractors with self serving purposes try to convince unsuspected home buyers not to have any inspections. After all the more buyers they can convince not to have inspections the less chance their work will be inspected and issues found. Good Builders and contractors who are confident in the quality of their work product will welcome you to have inspections performed and will typically encourage you, especially if you have doubts of what you are going to receive. Good Builders and contractors know their work might not be perfect and your own independent Inspector can help them find issues they might have overlooked. After all you are helping them pay for another quality control inspection of their work. On the other hand the less than good Builders and contractors don’t want you to inspect their work so they can short-cut, not build as required by building codes and standards, not have to take the proper time and effort to do it right, all of which saves them money!
It is very important that you do have a foundation pre-pour inspection performed. This is your only chance to make sure your foundation is being constructed properly as per the building codes and standards. Once the concrete is poured and everything is covered over it is to late to correct any issues that might cause or contribute to foundation issues later. Nobody has a crystal ball to help determine later if an improperly built foundation was a specific cause of foundation issues. No Builder, even the best, is going to dissect your foundation to determine exactly what caused the issue unless the foundation has totally failed and the home is uninhabitable (unlivable). By the way the term uninhabitable in “Builder Speak” means the structure is in imminent danger of collapse. This does not include cracking of drywall all over, binding/sticking doors and windows, etc., etc.
So what types of things do we see wrong when performing a foundation pre-pour inspection? There are so many things that can be done incompletely and/or improperly so I will only show a few dealing with the Post Tension Cables (PTC) used in most slab foundations in Texas. PTC are used typically in lieu of standard rebar (deformed steel is the technical name). These PTC provide the reinforcement for your slab and if the slab cracks and tries to pull apart the PTC are under high tension (pulled/stressed after the pour) and act to pull the foundation back together at the crack point. PTC foundations are engineered and in addition to the Engineer’s requirements the Engineer’s typically specify to use the Post Tension Institute (PTI) design and installation guidelines for anything they do not specify themselves. The PTI installation guidelines are very simple and yet many times not properly followed.
In this example picture we have the view of the PTC Dead End before the concrete is poured. The view is inside the form boards taken during a pre-pour inspection. The PTC Dead Ends are to be completely encased in concrete and are the end that is not attached to for stressing operations. The stranded PTC can be seen protruding out of the anchor and contacting the foundation form board. The PTI standards require that the tip of that cable be positioned no closer than 3/4″ from the form board to ensure it has sufficient concrete cover. As can be seen this cable is in contact with the form board and even if they pull the PTC back the nails holding the anchor in place have been over driven and would not allow it to move backwards very far or even far enough. Typically after the pour the only way to tell where the Dead Ends are located is where the anchor mount nails have been clipped off. In this case if left uncorrected the concrete would not fully covered the cable and it would be exposed to the weather and allowed to rust. If they pull the cable and anchor back without properly resetting the nails they might achieve 1/8″ – 1/4″ of concrete cover. That little concrete can easily break away in the future and expose the cable to the elements. These cables are under a great deal of tension and rusting cables can break at the mounts and release back into the foundation. The extent of any damage can not be readily determined UNTIL that happens.
In this three picture example we have a significant PTC installation error (first two pictures) and an almost properly installed PTC used as an example for the description. The Live End (called stressed end) of the PTC uses a conical shaped pocket former that the cable is inserted through (third picture). Inside the pocket former is a tapered tip that the cable is also run through and pointed to by the bottom arrow A hole is drilled into the form board and the cable and tapered tip is inserted into the form board hole. The conical pocket former is then mounted flush against the form board to seal off the pocket former opening and prevent concrete slurry from entering it and encasing the cable and wedge anchor points. This can cause problems with the stressing operation and proper seating of little wedges used to lock the PTC into the mount after stressing has been performed. As seen in the third picture the pocket former was not properly seated flush to the form boards.
The first two pictures are very important. In the first picture you see two PTC pocket formers reaching a form board at an angle. This form board was angled from the foundation lines to provide the decorative accent for that area. These two cables have been completely improperly installed. As can be seen the pocket formers in use can not sit flush to the form boards (wrong type of pocket former should have used angled former), the tapered tip is visible and right after it even the PTC itself is visible. During the concrete pour this entire pocket former can be filled with concrete completely encasing the cable, the mount, and the securing wedge mount points. If this is not corrected then when PTC stressing is performed it can break out the concrete around this cable and quite possibly around the PTC mounting bracket. That can easily compromise this cable. The next picture is what I found during the pre-drywall inspection for this house. You can see the remnants of the cut PTC cable on the ground from when they finished stressing, locking cable in place with wedges, cutting the cable, and filling in the pocket former with grout. A typical properly installed PTC will have a small, circular patched area on the face of the foundation where the pocket formed opening was (see picture in next issue description). Here there are large areas of concrete patch material used at the cable exit points and even on the ledge to the upper, left. This leads me to believe that they might not have repaired the original issue and had concrete breakout occur around these cables.
Here we have examples of PTC Live Ends that have not been properly cut and dressed. The end of the PTC should be cut back at least 1″ from the face of the slab. This can be reduced to 1/8″ if the tendon is properly capped (the white cap seen), the cap and gap to the foundation face is 1″ minimum in length, and the foundation contractor can ensure the integrity of the patch material used to fill the pocket opening. As can be seen these were not even filled in with grout when returning for the pre-drywall inspection. It was fully expected to already have been filled in.
In the third picture notice the darkened dot in the center of the patched Live End opening. In this case the contractor did not properly cut the cable back 1″ into the opening, did not place a proper cap on it like the other cables just displayed, and most likely the bare cable is barely if at all covered with the pocket patching material. Both of these conditions above leave the PTC easily exposed to the elements which can allow it to rust.
The issues noted above were ALL on the same foundation and only the tip of the iceberg for what was found with issues during the pre-pour inspection. I keep hearing various people, including the concrete contractor who spurred this Blog post, claim that you don’t have to worry and why pay for an inspection. After all they claim the Builder’s Engineer will perform and inspection as will the City. Well what happened here? When I performed this inspection the Builder’s Engineer had their “Green Sticker” on site saying the foundation was ready to go for pour. The City Inspector also green tagged it as ready for pour. There were many issues with this foundation and in my opinion it certainly was not ready for a pour! It was a very good thing that my client did not listen to all the self serving rhetoric on bulletin boards and chose instead to have a pre-pour inspection.
But wait isn’t this post about me trying to drum up more business for myself? Absolutely NOT! It does not matter whether you have a Texas State Licensed Professional Inspector perform your pre-pour inspection or if you choose to pay more for a State Licensed Professional Engineer to perform the inspection. What matters is that you do have the inspection and do not listen to the rhetoric of some anonymous BB poster telling you it is a waste of money! Most likely you’re spending hundreds of thousands of dollars for a new home. Also if you believe paying more for a home ensures proper quality this home starts at over $600,000.00 base before options. Do you want to pay that much money and scrimp a little on a foundation pre-pour inspection and gamble there are no hidden problems inside the foundation?
PS Inspection & Property Services LLC is a full service home inspection and light commercial inspection company servicing the entire Dallas and Fort Worth, Texas metroplex as well as all areas around them. If you are located outside of these areas I can still help service your needs so call to see how. I strive for the satisfaction of my clients in everything I do. The services offerings include:
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