shanewreckd t1_j9re0y5 wrote on February 24, 2023 at 12:39 AM

Rebar stake the first layer of timbers down, then secure the second layer over top the holes however you want, 10" spikes or GRKs or whatever you are comfortable with. Not much works better for the price than rebar for this kind of thing though. You could also set both layers, drill through, forstner the top of the hole larger, rebar them together deep, and glue a plug over the top.

BTTammer t1_j9shywq wrote on February 24, 2023 at 6:07 AM

This. I did rebar only through the first timbers on the ground. Then, i staggered the second layer so the rebar was covered and used lag bolts to fasten the two layers. Kids used the area for 10 years and never had an issue.

Bonus: If you want to reconfigure the area you just lift the timbers up off the rebar, reposition, and drive the rebar into the new area and slip the bottom timber with the hole over it.