a blond "guy" joke

A couple of blonde men in a pickup truck drove into a lumberyard. One of the blonde men walked in the office and said, "We need some four-by-twos." 

The clerk said, "You mean two-by-fours, don't you?" 

The man said, "I'll go check," and went back to the truck. He returned a minute later and said, "Yeah, I meant two-by-fours." 

"All right. How long do you need them?" 

The customer paused for a minute and said, "I'd better go check." 

After a while, the customer returned to the office and said, "A long time. We're gonna build a house."