Lumber Terminology 2

Jun 29, 17

Terminology and Why It is Important

I was just reading an interesting article in a lumber newsletter about the actual size of a 4x4. I have attached a link for your info.

This is an interesting article, but makes me wonder how many people out there are confused about lumber and lumber terminology.  In the last article, we talked about what a Board Foot (BF) of lumber is and why proper terminology is important.  When our customers call up and order lumber, siding or timbers they don’t really care how many BF they need, they just want enough lumber to complete their project.  For example, they may know that they need 20 pieces of 2x4x8 or six timbers that are 6x6x10. This is a simple way to order and we all understand what is needed. We will then place their order after figuring out what grade of lumber they need for their job - grade of lumber is a subject we’ll save for another day.

When a customer needs siding or wall paneling it is much more difficult for them to figure out how many boards they will need.  For example, you have a wall in your house that is 14’ long and 8’ tall and you want to cover with Douglas Fir 1x6 Tongue and Groove (T&G) paneling.  You need to cover 14x8 = 112 Square Feet (SF).  But don’t you need BF to figure out how many boards you will need?  What is the difference between BF and SF?  

You will need to convert SQ to BF.  A 1x6 T&G board doesn’t cover 6’’ because of planing it and considering the T&G portion of the board - it will only cover about 5 1/8’’.  Let’s look at a 1x6x8’ board which has 4 BF in it but only covers 3.42 SF of area per board.


1x6x8 = 48; 48/12 = 4 BF         

5-1/8x8 = 41; 41/12 = 3.42 SF


How many boards do we need to cover 112 SF?    112/3.42  = 32.74 or 33 boards of 1x6x8 T&G.

As you can see you have 132 BF (33 boards x 4 BF) of material but that will only cover 112 SF because of the width of the boards.  Different sidings and panelings have different conversions depending on the actual width of the board after planing.  Let Marks Lumber’s expert staff help you figure out your lumber needs!  Coming up in the next article - Linear Feet of material needed.

Answer to last week’s Questions:

How many BF in 10 timbers 8x10x16

Calculations- 8x10x16= 106.67 BF per timber x 10= 1066.7 BF in 10 timbers.

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