trimming trailer deck boards

[MikeA57]

How much do I need to allow for shrinkage on deck boards for a 16' trailer? The boards I have are 16' 1" long and my channel length is 15' 11 3/4". I put about a 13" board on the front axle under the board and my son stood on it but it was still too long by about 1/4" to get in the rear channel. I was going to trim it by about 1/2" but wanted to make sure it wouldn't shrink too much and be too short once they dried. Think I'll be safe with that?

 

[BeezFun]

Lumber doesn't shrink along it's length, it shrinks in the width and thickness directions. So you can cut it to easily fit and it won't get any shorter. I would try to clamp them together as you add boards across the width of the trailer, you'll get a fair bit of shrinkage in that direction, especially if it's pressure treated and is holding a lot of moisture.

 

[MikeA57]

Ahhh so, senor! Thank you. So how would I clamp the boards together as I add them? It is pressure treated BTW.

 

[BeezFun]

Ahhh so, senor! Thank you. So how would I clamp the boards together as I add them? It is pressure treated BTW.

There are clamps that use a piece of steel pipe as the bar, so you can make it as long as you want. I have one of those. But you can make up a lever that you use to force each new piece tight before you screw it in, so you don't really need clamps if you don't have them. Screw a piece of 2x4 block flat to the top of a joist and then use a longer 2x4 as a lever against it to tighten each piece. It's easier to push out the middle of a bow than it is to work each end of a bow, so orient the board that way to make it easier on yourself.