Can we have a thread about the use of Carbon Fiber as a foundation repair...

[StrucPatholgst]

Looking for opinions.

Here's mine:

While carbon fiber mat reinforcement is a proven technology in the world of commercial raised slabs (reinforcement around floor openings, etc.), I have a problem with the proliferation in the use and marketing of carbon fiber strips to reinforce or repair cracked and bowed CMU basement foundations. My concerns are:

1. I've seen a lot of marketing material showing photos of lab set ups where a CMU wall is reinforced with carbon fiber and then loaded to show how well the carbon fiber performs. Unfortunately the lab set ups do not reflect reality. These set ups are constructed with new materials and mortar, with no moisture conditions and no existing crack patterns.

2. I've seen carbon fiber strips on foundations in the field that were applied over areas of shattered block, over crumbling block, and over areas of efflorescence.

3. I've seen carbon fiber strips applied to CMU foundation walls that have bowed inward close to 2 inches.

4. In every case of these repair jobs, the homeowner is sold a perimeter drain system that involves drilling holes in the bottom course of block at the slab to provide a direct drainage path to a new French drain type of set up. In a good portion of these jobs, the perimeter drain is a plastic channel that sits just under a thin coating of concrete slab (less than 2 inches). To me this is not water proofing. This is merely water management. Also, the thin slab at the perimeter no longer provides lateral restraint at the base of the wall.

5. I've read the warranty paperwork for dozens of these repair projects, and they all state the same basic thing: the warranty is voided if the underlying block gets wet or deteriorates. Most of the warranties are also only for the product, not the wall. So a wall could shatter and the carbon fiber could hold the rubble together where it's applied, but neither the contractor nor the manufacturer would be liable for the warranty, because the carbon fiber is intact and it was the CMU between the strips that failed.

6. In every case I've looked at, if the wall deteriorates any further the only available option is full wall replacement. There's no way to save a deteriorating shattered wall that has already been repaired with carbon fiber.

So in my opinion, a large majority of these carbon fiber repair jobs have a limited life and are oversold with misleading marketing material. People seem to be undertaking these jobs for no other reason than to get through a sale of the property, with a carefully crafted transferable warranty that has loopholes, ultimately leaving the new owner to address what will one day be required: foundation replacement.

 

[phamENG]

We could have the same thread about foundation repair companies and the "need" to fix every drywall crack with $30k of screw piles. This is coming from somebody who lives in an area where basements are not permitted in new construction because this is a problem in virtually every basement in the area, so take it with however much salt you feel appropriate.

It's mostly a question of education. We have to educate the public about the limits of these systems when and where we can. The salesman isn't going to beyond whatever minimum requirements their company's lawyer told them they should. So the real question is how do we get that word out? Unless you catch one of these companies offering engineering without a license or report the engineer they use for unethical practice, there's not much to do but give second opinions.

Like I said, we can have another thread on foundation settlement repair companies. I could make a living following a truck around for one of our local companies and giving second opinions to everyone they give quotes to. Somebody comes to them with a problem, and they provide a solution. Is it the right solution? Is it the most economical solution? More often than not, no...but it's a solution that's available and the client thinks they need it. They don't make their sales convincing people that they have a problem...people call them and tell them they have a problem and ask for a solution. Until the public en masse realize that the better solution is to contact an engineer first, get an efficient and practical design, and then hire a contractor...this is what we have.

On the flip side of all of that...if the buyer is aware of these limitations, there may be nothing wrong with going ahead. Maybe I can't afford basement replacement and I have two kids about to start college. The carbon fiber may be a band aide, but if it's a band aide I can afford and get me through 8 years of tuition payments, then it might be the best solution for me right now. I agree, though, that If I were to sell it a year before the house collapses and tell the buyer 'oh yes what a nicely repaired and guaranteed basement wall we have'...I'd be a morally bankrupt arse.

 

[MotorCity]

A credible sales person of anything will tell prospective clients not only when their product is appropriate, but also when their product is not the solution. And to go one step further, if their product is not the answer, maybe steer the prospective client to a more appropriate product or solution. If a sales person is honest, they are more likely to be trusted when giving a sales pitch about their product. If a sales person tries to convince me that their product is the best, cheapest, has no short comings, etc.....I'm out.

 

[Guest090822]

MotorCity - you used the words "credible" and "salesperson" in the same sentence - thanks for the laugh of the day!