Retaining Wall Post Question

[dieselscout80]

One of the worst things I've had happen is for the deadmen to rot or become loose from decay. That requires an ENTIRE redig and rebuild of the wall. You might want to consider making the deadmen out of pipe instead. If the wall rots, you can replace the pieces without having to dig up and replace the deadmen. If you think you may be consistently wet and that you might have to replace the wall at some point, you might want to consider making the deadmen "permanent" and "re-attachable" to ease future repairs.

I've used a setup like this in wet areas in the past and it worked VERY well. Ultimately, we had to replaced the retaining wall 4x4s due to decay (after about 15 years) but we could just reattach them to the existing deadmen with no new digging.

View attachment 425693

That's a slick idea. :thumbsup:

 

[The Suburban Farmer]

That's a slick idea. :thumbsup:

Thanks, dieselscout. I HIGHLY recommend something like this if your wall is going to be damp. Makes it MUCH easier to replace the wall timbers, and it is just as strong, if not stronger, than traditional wooden deadmen. We used this all the time for walls around our farm ponds growing up, and the walls never buckled in, and replacing the face timbers was easy as could be. After 15-20 years, the pipes didn't have any rust damage that we could see.

I can't take credit for the idea, though. My dad was pretty darn ingenious when it came to building fixable things that didn't have to be "destroyed" to be "repaired."

 

[dieselscout80]

Thanks, dieselscout. I HIGHLY recommend something like this if your wall is going to be damp. Makes it MUCH easier to replace the wall timbers, and it is just as strong, if not stronger, than traditional wooden deadmen. We used this all the time for walls around our farm ponds growing up, and the walls never buckled in, and replacing the face timbers was easy as could be. After 15-20 years, the pipes didn't have any rust damage that we could see.

I can't take credit for the idea, though. My dad was pretty darn ingenious when it came to building fixable things that didn't have to be "destroyed" to be "repaired."

For a 30" wall how far would you go between each deadman?

 

[The Suburban Farmer]

For a 30" wall how far would you go between each deadman?

Depends on the soil type and the expected load. If the ground is going to be damp, that means "heavy" so I would probably do every 6 feet, but maybe 8 at only 30" high. According to one of my books, a 4-foot-high, 15-foot-long wall could be holding back as much as 20 tons, so you do the math. I tend to over-engineer things, but I would probably go every 6 feet, and make the "T" section of the deadman 4 feet (i.e., stick out 2 feet on each side of the center post) That gives enough undisturbed earth between each deadman, and should provide plenty of anchorage.

For our retaining walls around the ponds, we would also stagger each deadman so that every-other-one is 1-2 feet higher or lower than your starting deadman so you get support across both longitudinal and horizontal buckling, but that might be overkill in your case with only a 30" height. If it was taller, I'd suggest something like the pic below.

 

[The Suburban Farmer]

Also, make sure to use LARGE bolts for bolting the flanges to the wall and make sure they are water resistant (stainless or high-grade grade weather-proofed.) Those will be your weak points, so don't cut corners on the fasteners.

And DO NOT forget to add a drainage tile at the bottom to let the water run off instead of accumulating at the base of the wall. A few weep holes are a good idea, too.

 

[LD1]

Are you refering to concrete block for building or retaining wall blocks and do you have a link to them?

Retaining wall block.

No links, just what enards, home depot, etc carry.

 

[Streetcar]

For a decorative wall look at redi-rock.com

 

[Streetcar]

Depends on the soil type and the expected load. If the ground is going to be damp, that means "heavy" so I would probably do every 6 feet, but maybe 8 at only 30" high. According to one of my books, a 4-foot-high, 15-foot-long wall could be holding back as much as 20 tons, so you do the math. I tend to over-engineer things, but I would probably go every 6 feet, and make the "T" section of the deadman 4 feet (i.e., stick out 2 feet on each side of the center post) That gives enough undisturbed earth between each deadman, and should provide plenty of anchorage.

For our retaining walls around the ponds, we would also stagger each deadman so that every-other-one is 1-2 feet higher or lower than your starting deadman so you get support across both longitudinal and horizontal buckling, but that might be overkill in your case with only a 30" height. If it was taller, I'd suggest something like the pic below.

View attachment 425719

Remember that your board will need to span the distance between your deadman.
At six foot spacing your wall will bow out with boards, you would need six inch or thicker lumber

 

[LD1]

Retaining walls are no joke. Alot of people dont understand the forces dirt can put on a vertical wall when settling. Thats why they make the block. And use a fabric between a layer of block back into to dirt instead of deadmen.

 

[ultrarunner]

I helped my brother do one with railroad ties... good one that were hand selected... that was 15 years ago and some are no longer sound... it is not a critical area... just the same I'm sure if he had used block they would still be as good as new...