An important warning for consumers from the I-Team. There's crumbling concrete throughout town. But who's really to blame?

Back in May, we showed you how a batch of bad concrete caused driveways in our area to crumble after just one or two winters. After the story ran, we got tons of phone calls and e-mails saying, "Hey, the same thing happened to me." Turns out, the problem may be bigger than we thought.

We caught up with Milwaukee contractor, Jim Tomich at one of the dozens of driveways that's driving him absolutely crazy.

"As I walked up and I got a firsthand look at it, it was the typical 'sick to my stomach feeling' of 'What am I going to tell this guy?'" said a frustrated Tomich.

The New Berlin driveway is so bad, his crews came back to rip it out and replace it for free. Tomich said he had no other choice thanks to the scaling, cracking, crumbling concrete. Some spots look like someone took a jack-hammer to it.

"I've actually replaced driveways that are more than 50 years old that look better than this one," said Tomich.

When Dave Meinerz's son, now serving in Afghanistan, bought the house last year, the driveway seemed fine. Not for long. It's a hassle Meinerz never expected.

"When we bought the house, it's like wow," Meinerz exclaimed. "What's this and what are we going to do?"

Tomich's company, Polished Concrete, pours two to three hundred driveways a season. Tomich buys the concrete from Meyer Materials. However, in 2008, Tomich started getting phone calls, angry ones, from his customers wondering why their brand new driveways were falling apart after just one or two winters. Some worse than others. About 75 in all.

"I'm mad, frustrated, confused and quite transparently scared," Tomich admitted. "This is the kind of issue that can take my business down."

Hundreds of thousands of dollars in time and materials. The strange part, Tomich poured all of those bad driveways in 2006 and 2007. No major problems before or since.

"That's a big red flag," Tomich said.

A red flag because it's the same two seasons, and the only two seasons, Tomich says Meyer Material sold him a new kind of concrete mix.

"It's actually sold as a performance mix," explained Tomich. "It's better. It attains higher strength than straight six-bag mixes of [Portland cement]."

Tomich poured driveways with it thinking it would be stronger, and stand up to the wild Wisconsin winters.

"I assume when we buy the product that it's a product designed to do what we're using it for."

In this case, laying down driveways that won't fall apart even with freezing and thawing.

"Concrete placed right with a good mix should last forever," said Al Rusch, long-time masonry instructor at Waukesha County Technical College.

Rusch knows all the science, but the bottom line is this:

"If it happens too quickly, like within a year, year and a half, I would say that you've got concrete problems," said Rusch.

In this case, that concrete came from Meyer Materials.

So, what do the folks at Meyer have to say about all this? We don't know. The company's general manager said he'd do an interview with us. We tried for two months to set it up. At first he said he was too busy, and then he just stopped returning our phone calls and e-mails.

Jim Tomich thinks he knows why.

"I've asked [Meyer] how they're testing it, and the response I got from him was that it's field performance," recalled Tomich. "My indication was, when he said that to me, is, 'Guess what? It failed.'"

We wanted to ask Meyer exactly how it tests the concrete it sells to contractors, but so far haven't had the chance.

Now, Tomich is taking his own samples to figure out what went wrong.

"Had I known it was going to do this, there is no way in the world I would have ever bought this product," Tomich said.

Turns out, Meyer actually paid for Tomich to replace six of the crumbling driveways. Now he's fighting to get them all paid for.

So, what can you do if your driveway is falling apart? When it comes to concrete, state law doesn't deal with product quality. That means if your concrete driveway starts crumbling it's up to you to figure out who's to blame.