Engineered retaining wall recommendations?

[Brian]

We have a decent slope in our backyard. When we bought the house we had a granite rock/boulder retaining wall put in, but it only lasted a couple years before it started falling apart. At this point, many of the rocks are very loose, there's no soil behind some of the areas because of water erosion and critters getting in there and digging holes. I need to get a few quotes to rethink/rebuild it. Probably looking for someone to rebuild the wall, reusing what they can, and cement mortaring in the rocks this time, allowing drainage where needed. I probably need something more than the basic landscaper guy who can mow or dig in some bushes or whatever. I need someone who can handle the math (or whatever) needed to do it right.

Any recommendations?

[jerrymrc]

It may not be the "natural" look but the interlocking retaining wall I put in 15 years ago is still fine. I have a concrete retaining wall with a steep slope after. I cut into the slope and put up a wall that is right at the 4' level. Going to re-do the area soon but the wall has held up just fine. http://i884.photobucket.com/albums/ac44/jerrymrc/oldgroup135Medium.jpg (http://s884.photobucket.com/user/jerrymrc/media/oldgroup135Medium.jpg.html)

[Big E3]

We have stopped designing engineered cast in place concrete retaining walls due to liability issues. They are very expensive and always appear to be overkill when built out of poured concrete. We will typically tell our builders to just build it out of landscape timbers or stackable blocks as per the manufactures own specs.

You should find out what product they used to build the retaining walls around Cabela's at Lone Tree. I really like the way those look.

[Brian]

I would love to do interlocking bricks like that. Unfortunately, the HOA says any walls have to be built out of natural, local resources, and they specifically say no to interlocking bricks and wood timber/railroad ties, etc.

In a perfect world I was thinking something like this.


http://i.imgur.com/9TvoykW.jpg

Mentioned it to my neighbor the other day and he said "well you've been in the house 8 years, that's probably all you can expect" - man, I'm hoping he's wrong because I did have higher expectations.

[theGinsue]

Due to all of the rain, my best friend just had his retaining wall make from ~8"x12" concrete "core sample" tubes (put in by the original owner) collapse. He's looking to have the wall replaced with "local" 24"-36" rocks - with no mortaring (which I think is a bad idea). He's been quoted $14k and 4 days for the job. He can have all of the rock he needs delivered (18 truckloads) and rent a bobcat for a month to do it himself (with his fathers help) for ~$8k; but it will take him a month to do it. He needs this fixed ASAP because the erosion has eliminated 2 of his big decks footings and undermined 2 others (he's already paid someone to put in replacement footings for the 2 that were totally wiped out - costing him $1k.

Just giving you an idea of costs/time for some options.

[TheGrey]

It may not be the "natural" look but the interlocking retaining wall I put in 15 years ago is still fine. I have a concrete retaining wall with a steep slope after. I cut into the slope and put up a wall that is right at the 4' level. Going to re-do the area soon but the wall has held up just fine. http://i884.photobucket.com/albums/ac44/jerrymrc/oldgroup135Medium.jpg (http://s884.photobucket.com/user/jerrymrc/media/oldgroup135Medium.jpg.html)

Jerry, that's beautiful! Something like that is on our "list" of home improvements- our yard has one of those slow-but-treacherous slopes to the point where you'd better have traction on your shoes or you'll be leaving a sitzmark. I love the water feature you have, too.

[Brian]

Due to all of the rain, my best friend just had his retaining wall make from ~8"x12" concrete "core sample" tubes (put in by the original owner) collapse. He's looking to have the wall replaced with "local" 24"-36" rocks - with no mortaring (which I think is a bad idea). He's been quoted $14k and 4 days for the job. He can have all of the rock he needs delivered (18 truckloads) and rent a bobcat for a month to do it himself (with his fathers help) for ~$8k; but it will take him a month to do it. He needs this fixed ASAP because the erosion has eliminated 2 of his big decks footings and undermined 2 others (he's already paid someone to put in replacement footings for the 2 that were totally wiped out - costing him $1k.

Just giving you an idea of costs/time for some options.

Dang, maybe I'll just let it fall apart another year then. LOL. I think I may need to sell a kidney.

[Wulf202]

Would it be possible to use stone veneer over an interlocking brick? Without large amounts of drainage stone walls dont fare well here.

According to your hoa timber is not a local naturally occurring resource?

[Irving]

Can you order 10,000 copies of the HOA decs and build a paper mache wall?

[Grant H.]

Would it be possible to use stone veneer over an interlocking brick? Without large amounts of drainage stone walls dont fare well here.

According to your hoa timber is not a local naturally occurring resource?

I would look into this. Using a stone veneer over interlocking bricks will be your best option.

This is what I got to do one summer in our backyard...

Started out with this slope, which just looked like crap...
https://c2.staticflickr.com/8/7381/8874942674_5ce0d65d38_b.jpg (https://flic.kr/p/ewfpg1)How it started (https://flic.kr/p/ewfpg1) by ARNEWB (https://www.flickr.com/photos/61071044@N08/), on Flickr

Then started digging...
https://c1.staticflickr.com/3/2844/8874948382_e35bdda351_b.jpg (https://flic.kr/p/ewfqXq)Pile the dirt up (https://flic.kr/p/ewfqXq) by ARNEWB (https://www.flickr.com/photos/61071044@N08/), on Flickr

Then came the 18,000lbs of concrete retaining wall blocks...
https://c1.staticflickr.com/9/8255/8874341481_cf1891384c_b.jpg (https://flic.kr/p/ewcjxB)First layer and yard carnage (https://flic.kr/p/ewcjxB) by ARNEWB (https://www.flickr.com/photos/61071044@N08/), on Flickr

Not quite finished, but stands just over 4.5' in the corner...
https://c2.staticflickr.com/6/5335/8874960594_a3ba62d1c1_b.jpg (https://flic.kr/p/ewfuzY)Wall mostly assembled (https://flic.kr/p/ewfuzY) by ARNEWB (https://www.flickr.com/photos/61071044@N08/), on Flickr

I still need to get a picture of it all finished and the yard leveled, but the rest of the house projects continue...

[Grant H.]

A couple of things for if you just rebuild using the natural rocks...

1. Get some terra-grid (lots of different names for it). It gets buried horizontally and then laid between layers of rocks to tie it into the soil behind it.
- It can be used with interlocking blocks, but isn't necessary depending on height and design of the blocks.

2. When you back fill, mix the dirt with pea gravel for the first 8-12" horizontally from the wall. This aids in drainage, and will prevent a lot of your erosion problems.

[jerrymrc]

A couple of things for if you just rebuild using the natural rocks...

1. Get some terra-grid (lots of different names for it). It gets buried horizontally and then laid between layers of rocks to tie it into the soil behind it.
- It can be used with interlocking blocks, but isn't necessary depending on height and design of the blocks.

2. When you back fill, mix the dirt with pea gravel for the first 8-12" horizontally from the wall. This aids in drainage, and will prevent a lot of your erosion problems.

I had forgot about the gravel. When I put the wall in I used about 6" or so of gravel behind the blocks before I back filled it.