questions on driveway retaining wall

[05wrangler]

So this year I would like to start on my shop that will be built behind my house. So I will be expanding my driveway over to the edge of my property close to being against my neighbors paved drive and going back beside the house to the back yard. The house is naturally sloped away so I need to install a wall so I can put in a level gravel driveway. My questions are what are your guys thoughts on block vs railroad ties? how would you install the stone or block? What would you do for the base, dig down and lay stone or pour it? How far down? The wall only needs to be maybe 3 or 4 feet max in some spots. I'll try to post picture tomorrow so you can get a better idea.

 

[jhelrey]

Block, 90#s each, 1 course buried, Geo Grid, drain tile, gravel to fill block cavities if hallow, etc.

 

[inphx]

I think the footer under block needs a design like this:

Do you need a permit?

 

[Milton Shaw]

Rail road ties will have to be redone in just a few years. The ties are already used and probably have been in service 30 years or more. The large landscape block properly installed with first block half buried and sloped back will support and last a long time. If you use split face block use the 12 inch wide and fill with concrete and rebar and you will never have any problems. They would require a footer but would be good for 100 years or more. That high a wall may require a railing if it's going to be inspected.

 

[machsnell]

Either really just know wood does rot. Block will last your lifetime if done right.

There is block like keystone wall block with grid that gets laid back into grade typically equal to the height of the wall. More excavation required.

Thenthere is a block wall where you have concrete footing rebar and then block up from there filling cells where vertical bars are.

Then there are timbers. You said rr ties. They are better and last much longer but they are so heavy they are a a pain to set.



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[Ty.]

Block, 90#s each, 1 course buried, Geo Grid, drain tile, gravel to fill block cavities if hallow, etc.

Bingo!

Those big heavy block are what are specified for DOT projects because they do not move once installed properly. The most important thing is to bury the first course below grade, and make sure you remove any organic material before you start installing, ie any sort of top soil. Your best bet would to be to remove a foot below grade and set a base out of road gravel or 3/4 inch aggregate for a solid base. Take your time setting your base row properly and level side to side, and slightly pitching back. Once that is in you can build the wall as fast as you can stack 90 lb blocks, haha.

 

[555]

Our Georgia house has railroad tie retaining walls. They were used when they were installed in 1994 and are rotten now. I'm in the process of replacing one long wall and one fairly short wall. The long wall parallels the driveway and I am replacing it with concrete blocks. It's approximately 25 feet long and 2.5 feet high (highest point). The short wall is 10 feet long and 18" high and I'll replace it with decorative block that mimics natural stone. The railroad ties are ugly and leach out creosote whenever the temperature gets in the 80s.

 

[M35A2]

I would use the stack block. I have several that I have done around my place using the 60lb block from Lowes. I always set mine on a 6" poured footing with rebar so you don't get the ripple effect years later. Drain and rock backfill is a must.

 

[padroo]

I built a large raised patio on the back of my house in 2009 and used Alen Block


http://www.allanblock.com/products/retaining-walls.aspx

To hold back 40 cubic yards of limestone. You don't have to dig very deep but you do need six to eight inches of compacted stone to start your first course of block. You need to install a drain the length of the wall at footer level, after that it is just stack the block, backfill with some stone on the backside of the block then dirt. My patio shows no sign of heaving after several cold winters. The compacted stone and drain are very important.

 

[rosesiegel]

Rail road ties will have to be redone in just a few years. The ties are already used and probably have been in service 30 years or more. The large landscape block properly installed with first block half buried and sloped back will support and last a long time. If you use split face block use the 12 inch wide and fill with concrete and rebar and you will never have any problems. They would require a footer but would be good for 100 years or more. That high a wall may require a railing if it's going to be inspected.

 

[bczygan]

You need an engineered retaining wall, especially since it will get loads from vehicles.

 

[ford33]

I don't recommend a wood wall. We have them in our townhome complex. They were installed in the mid-90"s and are falling apart. Replacement is with landscape block.

 

[05wrangler]

Thanks for the info guys. Ill.post pics today and go with blocks. How far down below the surface would you guys go? I see making sure one row is below but how much stone underneath and would it help to maybe put two rows in the earth?

 

[matt_i]

I would also build it with a curve or curves, as viewed from overhead. Its considerably stronger that way as opposed to a big flat plane.

 

[Jess]

I second the use of quality landscape blocks. Allan Block or similar should be available and the manufacturers web sites have installation guides on line to give you an idea of heights and foundation requirements. We did a wall replacement along the street at a place that was 4' high, with a crushed rock foundation below grade and a foot deep, well compacted. The original poured wall failed due to the cedar hedge roots pushing on it for years. Most walls of any significant height should have an engineered design for longevity and safety. Wood, so called landscape tie walls are a disaster in waiting. Railroad ties used to be big, but the leaching and eventual replacement is expensive with proper disposal of the old ties and timbers. Burning around here has been banned

http://www.allanblock.com/
https://www.lowes.com/projects/gard...guide/project?cm_cr=null_1_Design+With+Pavers

 

[05wrangler]

OK here are some pics, my house it on the left.the drive will extend up.to a foot away from the guys overhang. So about 11 feet off my house. I roughly measured it and looks like the Lowe's pint is about 25 inches difference

 

[05wrangler]

Well I guess my house is the one on top lol sry

 

[bczygan]

Landscape blocks will not do for a driveway.

 

[05wrangler]

Landscape blocks will not do for a driveway.

What type of block should be used?

 

[Kaizen]

What type of block should be used?

It is fine. I think he thought you were talking to drive on not a retaining wall.
Can you legally put your driveway that close? That's gonna be a long wall. use string lines to lay it out straight.

 

[05wrangler]

It is fine. I think he thought you were talking to drive on not a retaining wall.
Can you legally put your driveway that close? That's gonna be a long wall. use string lines to lay it out straight.

I called to have the County "driveway engineer" guy come out and have a look but I was also told that there are no restrictions on a driveway being that close where I live

 

[rburke65]

Yes. I don't think he has read the previous posts.

 

[05wrangler]

Do you guys just use stone to fill in the block? Would it be worth it to mortar them together? "Slush" a row or two like a normal block wall?

 

[Kaizen]

Do you guys just use stone to fill in the block? Would it be worth it to mortar them together? "Slush" a row or two like a normal block wall?

hell no. these walls are designed to move with the frost and then settle back under its own weight. since this isn't really retaining much more then 1 or 2 feet you can do any size block. have one whole block below grade and 6 inches of stone under that. landscape fabric might stop some of the silt but after a year if you don't put it in there isn't any left.
most important thing on this project is 1st row has to be perfectly level. that it. you can do anything you want for a design as long as its level. because of the lay of your land you'll have say twenty blocks in a row that are level with blocks on top that lead into the next twenty that are level with each other.
use 16 inch ones so they go fast. 95 percent of the project is the first layer. after you do that you are done in an hour of moving block.

 

[kwschumm]

When a lot of weight will be behind the wall (like moving vehicles) I'd recommend geogrid fabric every other course, sandwiched between the blocks and embedded and compacted in the gravel behind the wall.

 

[padroo]

Thre term landscape block to me implies mostly for looks, commercial retaining block are what you build a wall out of.

Unilock is another major supplier of retains block. Go to a place that sells brick and block to contractors, some of the home centers may sell them.

 

[metalmagpie]

We built a railroad tie structure in our yard. I would never do it again.

metalmagpie

 

[ms fowler]

Do you guys just use stone to fill in the block? Would it be worth it to mortar them together? "Slush" a row or two like a normal block wall?

The landscape blocks are an engineered product. You should have someone qualified to look at your plan. There is liability if your wall causes problems for your neighbor. The block supplier may be able to make recommendations. Having a local geo-technical Engineer design the wall shouldn't be more than a few hundred dollars.
Do not try to "improve" the design of the blocks by mortar or anything else. The clean stone used to fill the blocks locks the courses together and permits drainage. You want the water behind the wall to drain out. Holding that water behind the wall adds to the earth pressure on the wall and causes overturning.
The height of your wall does not appear to present any problems.

 

[kbs2244]

You are going to have a problem with your neighbors rain run off.
That downspout is dumping a lot of water right on the lot line.
You will need a lot of drainage at the foundation level.

I would think about a professional install.

 

[05wrangler]

You are going to have a problem with your neighbors rain run off.
That downspout is dumping a lot of water right on the lot line.
You will need a lot of drainage at the foundation level.

I would think about a professional install.

I am going to step back about 12 to 18 inches back from his drive edge to keep the natural drainage going and poke out my gutter do spout through the wall. Also take a drainage tile down the wall to the back end where the land evens back out and let it daylight and drain to its original spot

 

[Radix2]

Your time and effort is too valuable to waste on wood walls. Installed properly, this can be a once and done project... never let material cost turn one of those into a maintainance and or recurring project is my advice.

I built a ton of walls out unilock's wall blocks 25 years ago. They still look the same as new... good thing too, because I have a stack of other stuff that needs doing...

 

[ms fowler]

More about segmented block walls...
I have inspected the construction of these for 20-30 years. When properly designed and constructed they are excellent. I have seen several that approach 100 feet tall...with traffic near the top surface.
I also have investigated a failure or two. One of these "failures' was particularly interesting. It was 10-15 feet tall and was located maybe 40' from the side of a Home Depot with a traffic lane between the wall and Home Depot. The footing was properly excavated, compacted and tested. Nothing unusual was observed. However, within a year of the wall's construction a zone of settlement was observed--about a 3-5' long section of the wall began to droop, about 8" total. Investigation disclosed a previously unknown drain pipe perpendicular to that section of the wall. That drain had been installed long ago, and without compaction. The years left no trace of surface disturbance and the compaction of the footing for the new wall in that area showed nothing different than the rest of the wall.
The wall and the Fill behind it remained stable. The traffic surface was leveled and re-paved. The "droop" is still obvious to this day and its been 10 years or so since it was built.
Here is my point--even with that flaw, the wall remained in vertical alignment and safe. The geo-grid and stone infill did the job they were design to do. The factor of Safety of these walls is very high.
This is why I suggest that no one tries to "improve" the design. They are good products when built as designed.

 

[reader2580]

Locally they make a retaining wall block that is flat and uses pins to hold them together. These style of block are ideal to use with a footing.

A neighbor of my parents probably 20 years ago put up a four foot tall retaining wall. It collapsed in under 30 days. He put a footing underneath and it still stands today.

 

[05wrangler]

Thanks guys for the info, I'm miles ahead from where I was when I started the thread.

 

[Bondo]

Ayuh,.... For what it appears ya wanta do, ya don't need any retainin' wall,....

For one thing, the last thing ya want is a Level driveway,....
It's gotta be pitched to carry the water away,....

If the lawn in the picture is boxed out, 'n refilled with stone, at the grades there now, the water will flow, as it does now,....

In the pictures, the grades are such that a retainin' wall is gonna be nothin' but a problem, in many ways,....

 

[ard]

It is fine. I think he thought you were talking to drive on not a retaining wall.
Can you legally put your driveway that close? That's gonna be a long wall. use string lines to lay it out straight.

Or curve it a few times, to create more visual interest, as well as potentially a few planting areas.... (and hide any 'wiggles' that creep in... )

 

[ptgarcia]

I recommend contacting the engineering department of your local governing agency (City or County, whichever applies) as they most likely have an approved wall design available for your situation. It will likely save you some grief in the future.

Also, be careful of the effects of your wall on your neighbors property. Understand the effects of wall loads underground if there are neighboring structures nearby and be sure to address drainage so that your water doesn't drain onto your neighbors property. Going from turf (pervious) to concrete/asphalt/gravel (non-pervious or semi-pervious) increases surface run-off and it's your responsibility to mitigate that. You don't want your water damaging your neighbor's property.

Good luck with your project!

 

[theoldwizard1]

3 things

1. Foundation
2. Drainage
3. Tie Back

1) If the wall is not more than about 4' tall AND each corse of blocks are secured (not glue or mortar) together you can probably get away with one block below the low side grade as long as it is resting on 6" on compacted gravel.
2) You need pipes to drain the water down hill. They need to be separated from the soil be HD landscape cloth. Back fill with gravel between the cloth and the wall. Weep holes in the wall
3) Anything over 4' need tie backs.