BOSTON (CBS) – When Sophia Sullivan decided to build a new deck on her home in Oxford she chose to do business with the national chain Lowe’s, thinking she’d be better protected if something went wrong.

“These are supposed to be attaching the deck to my house,” Sullivan explained to WBZ-TV while pointing at dozens of bolts left in her backyard shed.

Her brand new deck is not considered safe.

“They skipped a number of the fasteners so the boards aren’t attached,” she noted while pointing at the floor boards clearly missing screws to hold them in place.

Because of the shoddy workmanship, the deck failed inspection. “The gate is here because these stairs are not safe,” said Sullivan, as she pointed to the gate blocking off the main entrance to the deck.

This all started back in March, when Sullivan hired Lowe’s to install the deck.

“Horrible. Horrible. I wouldn’t wish it on my worst enemy,”she said, describing her experience with the chain.

The first sub-contractor hired by Lowe’s never pulled permits from the town. The second sub-contractor was the one who didn’t use all the bolts.

That’s when Sullivan reached out to the WBZ’s I-Team.

“You reached out to them, and I did get a phone call, funny enough, that afternoon. And then all of sudden things started picking up,” she said.

When we contacted Lowe’s they agreed to fix Sullivan’s deck. The project was completed to Sullivan’s satisfaction in September. In a statement Lowe’s told WBZ, “when we learned the installation didn’t meet local inspection requirements, we immediately stepped in and made the necessary changes.”

But the I-Team took a closer look at the Lowe’s home improvement contract, which required Sullivan to pay for her deck in full before work began, more than $12,000.

“I was told that was the only way that they would do business,” explained Sullivan.

Ivy Schutt of Littleton said she was told the same story when she handed over $41,000 before any work began on her kitchen remodel.

“I thought it was one-third, one-third, one-third. And they said that’s not Lowe’s policy,” said Schutt.

Same story from Susan Bartzak-Graham of Newton.

“I was told that I had to pay everything up front and that that was Lowe’s policy,” said Bartzak-Graham, who paid more than $30,000 for a new kitchen and bath.

Both women were dissatisfied with the results and how long it took to get the job done.

“I had no way to say ‘go away.’ They had my money,” Schutt told WBZ.

The I-Team took the Lowe’s contract to the Office of Consumer Affairs and Business Regulation to ask if it was legal.

“As written now, no it is not,” said John Chapman, the Undersecretary of Consumer Affairs.

“What was wrong with it, is that it was requiring consumers to pay 100-percent upfront and that’s not what the law states,” said Chapman.

The law states “any deposit… cannot exceed one-third of the total contract price” before work begins. Consumer Affairs immediately reached out to Lowe’s and Lowe’s agreed to make changes.

“This is a great effort by our office, as well as your news station, to identify something that was off and needed to be corrected,” Chapman told WBZ.

In a statement Lowe’s told the I-Team, “We are clarifying our installation contract language and are redoubling efforts to educate employees about payment collection for installations.”

The Office of Consumer Affairs says homeowners should do their homework before hiring any contractor by checking references and making sure they are properly licensed.

If you hire a big store for the job, you can still check out the history of the sub-contractor who will actually be doing the work.

If things go wrong, the state has a fund to compensate homeowners. The reimbursement is capped at $10,000 for homeowners who have successfully sued the contractor but can’t collect the money.

RESOURCES FOR CONSUMERS:

The Massachusetts Home Improvement Contract Law:

Required Home Improvement Contract Terms:

To check if a contractor has a license:

To see a sample contract:

To apply to the state’s guaranty fund, review a contractor’s history, or to learn more about home improvement protection: