A class-action lawsuit filed in Chicago claims Home Depot deceived buyers who purchased four-by-four lumber, without disclosing the boards' true measurements are 3.5 inches by 3.5 inches.

“Defendant’s representation as to the dimension of these products were false and misleading,” the suit against Home Depot alleges.

Related: Home Depot faces lawsuits over lumber size description

Home Depot and other lumber supply companies that spoke with KHOU 11 News Thursday say it is common knowledge among those in the construction industry as well as consumers that two-by-four and four-by-four refer to names of boards, not exact dimensions.

"We disagree with the claims in the suit,” said Home Depot communications director Stephen Holmes. “The names for lumber sizes are standard across all lumber suppliers and retailers that sell lumber."

KHOU 11 News measured a four-by-four bought from Home Depot, and the dimensions were 3.5 inches by 3.5 inches. The measurements were the same for other four-by-fours at lumber yards visited by KHOU 11 News Thursday.

“As long as the wood is to whatever those industry standards are, it may be named a four-by-four,” said Diane Easley from Grogan Building Supply. “But it’s not 4inches by 4 inches.”

Grogan’s Building Supply has been operating at its Heights’ location for nearly 80 years. Easley says there was a time when two-by-fours and four-by-fours had measurements consistent with their names, but the industry standard for both changed many decades ago.

Easley said she has never heard of anyone returning a four-by-four because it measured 3.5 inches by 3.5 inches.

The plaintiffs in the Chicago lawsuit against Home Depot are seeking in excess of $5 million.