But for ground contact, as in a retaining wall, you need wood labeled UC4. After that, you should see an A, B or C, signifying general use, heavy duty or extreme duty. Advertisement.

I want to build a three-foot-high retaining wall behind my house out of pressure-treated wood. Thoughts?—Shawn B., Sioux City, Iowa Go ahead, but do your homework. First, call 811 before you dig ...

Household retainer / Whether of wood, mortared materials or interlocking blocks, retaining ...

How to Build a Curved Retaining Wall & Fire Pit Area Treated Pine Sleepers DIY Guide. Posted: June 19, 2025 | Last updated: June 19, 2025. LVL UP Building & Maintenance Welcome to LVL UP Building ...

But for ground contact, as in a retaining wall, you need wood labeled UC4. After that, you should see an A, B or C, signifying general use, heavy duty or extreme duty.