tie backs, anchoring, carbon fiber?

[cstrain]

Our house is under contract to sell and our buyer's inspector found a crack in the cinder block foundation wall in the basement. They obviously want this looked into and repaired.

The crack is about 2/3 the way up the wall, horizontal, about .05" (I can fit a dime in it, just barely) with slight bulging of the wall.

I have a residential structural engineer coming out next week to give us a repair plan (we are paying for his services) as well as a contractor the buyer chose coming out to do a "free estimate".

When I spoke to the SE on the phone he was talking about what I believe to be using a wall anchor system like this:

http://www.wallanchor.com/gifimage/wallaftr.gif

The website of the contractor the buyer chose says that they use helical anchors like this:

http://www.kcwaterproofing.com/images/basement-tieback.jpg

or carbon fiber reinforcing, like this:

http://www.levelift.com/images/CarbonFiber1.jpg

(sorry, I'm sure that y'all already know what all of these are, I just want to make sure I have this all right)

so my questions are

1) is there a big difference btwn the helical tie backs and the wall anchors? is one much more invasive than the other? they look almost the same

2) is there an advantage to the carbon fiber reinforcing versus the anchors/tie backs? structural advantage, or cost advantage?

Thanks in advance!

[TJ1962]

The biggest differences are the way that they are installed.

1. Many anchoring systems required a "dead man" so outside excavation may be required. The helical is driven without excavation.

2. There are a few advantages with carbon fiber. Applied directly to wall. Very little creep or loosening as it becomes part of the wall and very low profile (does not stand out). It usually does not give red flags to small problems.

As with just about everything pricing would be dependant on area, contractor, condition of foundation, number of units installed etc.

[FIXITGUY1971]

With a cement block wall in expansive soil I would be very careful with tie backs or anchors. These systems both require monthly bolt tightening. They are well suited for solid poured walls but can sometimes be subject to "punching shear" because of the small anchor plate contacting only a few blocks.