Floor Joist Crown Up Or Down

The crown of a piece of dimensional rough lumber is the upward arching curvature you see when you look down its narrowest dimensional edge.

Floor joist crown up or down.

This article explains the causes of wood board cupping and gives advice concluding that unless a board is already badly cupped or has a bad side when construction of outdoor decks and wood stairs you should place. A crown will be the edge of the lumber that warps upward in the center when holding it on edge. Best i can tell this may have been like this when the subfloor went down as the subfloor is well attached to the joists in this area. Arrange the boards by the amount of crown they have don t put a joist with minimal crown next to a joist with a high crown.

Like when you put in floor joists you always try to put the crown up. I went into the crawlspace with a level and that joist is bowed up about 3 4 to 1 compared to the other joists on either side of it. This article series explains the causes of cupping in wood boards wood board right side up advice for steps decks ramps. The crown will not be the same for each board.

This means using two screws on each end and using two screws towards the outside of the boards at every joist along the way. In reality you can decide which way is best for orienting the boards whether you re installing a new deck surface or. The result is either a cupping of the wood or a crowning depending on which way you face the board. Bark side up or down on exterior wood decks stairs.

When i use crown i m speaking of the variation from straight that you see when you site down the edge of the board. Many people feel that bark side up is always the answer but this is not accurate. The objectives for orienting the decking bark side up or down are to minimize cupping which leaves raised edges for feet to catch on reduce splitting aka checking diminish the chance for rot and have fewer splinters. In other words a 2 10 would be held up on one end with the 10 dimension being vertical.

The board will shrink and warp in the opposite direction of the rings in the wood. Your joist boards will have a crown if you look along the edge the board will swoop in or bow out. When you are framing a floor system for example you need to look down the edge of the lumber and decide which side has what is called a crown. Always mount the joist and beams bowed upwards.

A board that is correctly installed right side up or bark side down will form a crown and allow water to run off the edges. In my son s bedroom there is a raised spot in the floor along one of the joists. The strongest way to secure deck boards to joists is by using the top down face mount screw method. The debate about whether deck boards should be placed bark side up growth rings curving down or bark side down growth rings curving up has raged for years.