Why is a 2×4 not a 2 by 4

Learn the Reason why a 2×4 doesn’t Actually Measure 2 inches by 4 Inches

By Mark J. Donovan




In this video Mark Donovan of HomeAdditionPlus.com explains why a 2×4 doesn’t measure 2 inches by 4 inches.

Have you ever wondered why a 2×4 doesn’t measure 2 by 4? If so read on.

When a 2×4 is rough cut at a lumber yard it does measure 2 inches by 4 inches. This is known as the nominal dimension of the lumber. However, after the piece of lumber is cut, it is dried for a period of time and then planed to ensure that it is straight and smooth.

This drying and planing process causes the rough dimensions to be reduced to the actual dimensions of 1.5 inches by 3.5 inches.

Thus, this is why the 2 by 4 that you buy at the home improvement center only measures 1.5 inches x 3.5 inches.

In regards to the length of the 2 by 4, the nominal and actual measurements are the same. So, for example, when you purchase an eight foot 2×4, it actually does measure eight feet in length.

Why is a 2x4 not a 2 by 4

For more help on building a home addition, see HomeAdditionPlus.com’s Home Addition Bid Sheets. Our Home Addition Bid Sheets provide you with the knowledge and information on how to plan a home building project, and what to look for when hiring contractors. They also include detailed cost breakdown tables and spreadsheets for estimating your own new home construction building costs.

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