2x12 redwood stair treads cracking in center

JimmyRrichards · 08-09-2011, 01:01 AM

I replaced 4 of my stair treads with 2x12 redwood and each of the pieces is cracking in the center around 6 inches in. Ironically, the reason I am changing them is because the old pressure treated treads were cracking in the middle also. I used 3 screws on each side to screw each tread into the stringers. The stairs is very narrow (29") so there are only 2 stringers in total. Does anyone have any idea why my treads are cracking. I want to find out before I replace the remaining steps. Thanks so much.

Just Bill · 08-09-2011, 07:09 AM

A third stringer would insure proper support. That is the only thing i can see that might be missing. Were the screw holes predrilled???

zircon · 08-09-2011, 08:47 AM

That 12" tread will vary in width as the seasons change and the moisture content varies. The treads are cracking as they shrink because you have them restrained with the three screws. Put the middle screw in as you have it, but the two outside screws should be in about a 3'8" long slot so the tread is free to move when it has to.

Ron6519 · 08-10-2011, 10:39 AM

Remove the 2x12" treads and replace them with 2, 2x6" pieces.

mikey48 · 08-10-2011, 11:29 AM

I agree with Ron. Leave a small space between them.