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View Full Version : Novice building a retaining wall: Pics and drawings included


blkhawk661
05-21-2012, 03:14 PM
I am renting an excavator this weekend to take advantage of the holiday and I intend to start a retaining wall. I really appreciate getting some of the expertise from fellow board members.

Below are pics and a rough drawing of the back yard. My questions are such:

1) Changing elevations: If I only built the wall to the height of the current terrain i'd be changing the level of my base multiple times. Which doesn't sound right. Given my lack of experience, should I just make the the base the same throughout? I hesitate to do this given additional dirt removal and cost.

2) Drainage: I had planned on using a single PVC pipe behind the base layer running the length of the way and draining on the far side away from the patio. Open to the air by point F. Additionally, 12 inches of gravel will be placed behind the wall per mfg specs. Is this sufficient drainage?

3) How do I over build?: I plan on being in this house for some time (perhaps 50 years) and later building a paver patio on top of it. My son will play on this, so I want it to be fail safe. I plan to use geogrid every other level starting with base and bury the entire first layer. Is reasonable? Any other considerations I should make?

4) Stairs: I tenatively would like to put stairs in between points B and C (though not 12 ft wide of course). Do i need to dig out that entire area or just step cut with new levels of base? Any special drainage requiredments?

Many thanks to all that reply.

Other pertient information:
- i chose the base of the tree as the target height becuase the base of the cement pad is even higher and would require a much taller wall. I am not tied to this though.
- climate is northern KY (clay soil)
- product I plan to use is Mesa Block - Standard unit block since I can get it for $5.60 a block. Dimenstions are 18x12x8
(http://www.tensarcorp.com/index.asp?id=476)
- since I am impatient and cheap, I have not consulted a civil engineer

Questions comments? Any other considerations I should keep in mind?

shovelracer
05-21-2012, 04:55 PM
Adding stairs will greatly increase your time spent and also your cost. They also are more difficult to do properly. The wall will be 4.5' tall correct? This makes for a heck of a fall off the top. Will you be fencing it in? Perhaps you might want to build a double tier wall below the stairs and a single above. You can just lay a single elevation layer and it is generally faster and easier, but you will bury probably 2 pallets worth of block. Maybe just want to make a few steps of greater elevation.

All this said it generally is not recommended to build a wall of engineer required size your first time out. At least if you forked out a few hundred for the engineer you would know what certain dimensions to use. Sounds like you could pay for it out of the money you intend to use for overuse of geogrid and buried stone.

SSmith
05-21-2012, 05:39 PM
The amount of fill is going to be massive. Do not use pvc....use drain tile. I'm in Cincy and I feel like I should help you, but it's a holiday weekend and I'm taking it all off. I have a small child too and a soft spot in my heart for DIY's even if it means one less potential customer. If you plan on taking a while to finish this project then feel free to pm me and I can consult with you....maybe even drive down there and take a look.

blkhawk661
05-21-2012, 07:49 PM
pm me and I can consult with you....maybe even drive down there and take a look.

I think my low post count restricts my ability to pm. Nor can I reply to pms( or at least I can't re: to the admin's pms)

If you pm me, then I will happily email or call you. I appreciate your generousity with your time.

blkhawk661
05-21-2012, 08:00 PM
Will you be fencing it in?

No, I was going to plant rose bushes or boxwoods as a deterrent. My boy is only 14 months and nothing will completely prevent him from always being covered with bruises.

At least if you forked out a few hundred for the engineer you would know what certain dimensions to use. Sounds like you could pay for it out of the money you intend to use for overuse of geogrid and buried stone.


Agreed, but my decision to do this was recent. The equipment rental store is only charging 1.5 days for 3 days since they are closed for the holiday. I have the time and I was getting a deal so I switched into "obsession mode" .

So here I am. Trying to learn how to build a wall, buy the materials, rent the equipment and start building it all in a weeks time.

FYI - last week I didn't know how to use a chain saw and I ended up buying one for cutting down a 60ft tree that was 30 ft from my house. (the stump in the pics)

I don't have hobbies, i have obsessions.

DVS Hardscaper
05-21-2012, 08:18 PM
drainage chimeny should be no less than 18-inches wide.

with equipment rantal and all - it'll cost you more to do it yourself than paying a competent contractor :)

SSmith
05-21-2012, 08:33 PM
I think my low post count restricts my ability to pm. Nor can I reply to pms( or at least I can't re: to the admin's pms)

If you pm me, then I will happily email or call you. I appreciate your generousity with your time.

I can't even pm you. I believe you need 10 posts is all.

blkhawk661
05-21-2012, 08:34 PM
drainage chimeny should be no less than 18-inches wide.

oh geez. I just googled "drainage chimney" and I had no idea. I thought drainage was just going to be pvc or drainage tile with was backfilling 12'' of gravel.

with equipment rantal and all - it'll cost you more to do it yourself than paying a competent contractor :)

$300 for the excavator, and maybe $200 for my cousins to help me out.

You really think I can find a contractor who will put in such a long wall for only around $500 in labor?

blkhawk661
05-21-2012, 08:35 PM
I can't even pm you. I believe you need 10 posts is all.

half way tempted to cheat the system to get to 10

SSmith
05-21-2012, 08:36 PM
oh geez. I just googled "drainage chimney" and I had no idea. I thought drainage was just going to be pvc or drainage tile with was backfilling 12'' of gravel.



$300 for the excavator, and maybe $200 for my cousins to help me out.

You really think I can find a contractor who will put in such a long wall for only around $500 in labor?

There probably are a lot of "beer money" guys who'd do it for that!

blkhawk661
05-21-2012, 08:40 PM
There probably are a lot of "beer money" guys who'd do it for that!

and with that, i have 10 posts and will try to pm you

SSmith
05-21-2012, 08:44 PM
There may be a delay

blkhawk661
05-21-2012, 08:51 PM
and with that, i have 10 posts and will try to pm you

and I failed.

SSmith, please just email me at "blkhawk661@aol.com" and i will email / call you back.

Obviously, this is my junk email address and people can spam it all day for all i care.

blkhawk661
05-22-2012, 12:34 PM
1) Changing elevations: If I only built the wall to the height of the current terrain i'd be changing the level of my base multiple times. Which doesn't sound right. Given my lack of experience, should I just make the the base the same throughout? I hesitate to do this given additional dirt removal and cost.

2) Drainage: I had planned on using a single PVC pipe behind the base layer running the length of the way and draining on the far side away from the patio. Open to the air by point F. Additionally, 12 inches of gravel will be placed behind the wall per mfg specs. Is this sufficient drainage?

3) How do I over build?: I plan on being in this house for some time (perhaps 50 years) and later building a paver patio on top of it. My son will play on this, so I want it to be fail safe. I plan to use geogrid every other level starting with base and bury the entire first layer. Is reasonable? Any other considerations I should make?

4) Stairs: I tenatively would like to put stairs in between points B and C (though not 12 ft wide of course). Do i need to dig out that entire area or just step cut with new levels of base? Any special drainage requiredments?


anyone else have opinions on my initial questions?

zedosix
05-22-2012, 09:58 PM
anyone else have opinions on my initial questions?

Once you get to 1000 posts I'll help you. :laugh:

AztlanLC
05-22-2012, 10:59 PM
No wonder you never reply to my posts zedo :)
Well honestly to help you tackle that wall we need to write about 30 pages worth of information if not more good luck finding someone willing to put that time and effort

SSmith
05-23-2012, 08:05 AM
No wonder you never reply to my posts zedo :)
Well honestly to help you tackle that wall we need to write about 30 pages worth of information if not more good luck finding someone willing to put that time and effort

Nonsense. It'd only be about 25 pages.

I talked to this gentleman on the phone yesterday for 35 minutes. Very friendly and smart fella. Seemed like he had a lot of common sense which isn't very common.

DVS Hardscaper
05-23-2012, 09:16 AM
You're gonna need more than an excavator. Unless you wanna hump 30 tons of gravel with a wheel-barr. I don't think you realize what you're about to get into.
Posted via Mobile Device

zedosix
05-23-2012, 01:14 PM
You're gonna need more than an excavator. Unless you wanna hump 30 tons of gravel with a wheel-barr. I don't think you realize what you're about to get into.
Posted via Mobile Device

Come on, 30 tons? At 2" base you'll only need a pick up truck full.

blkhawk661
05-23-2012, 01:25 PM
I don't think you realize what you're about to get into.

Correct, I didn't know. I thought a SRW was just building a base, adding drainage, and stacking block. I used to think that lots of time, sweat, and a little blood was all it would take. No longer.

I spoke with SSmith and then had a landscaper come out yesterday and they totally rained on my parade. :)

Given the following information, I have decided to cancel my venture
- the wall would be in a drainage field, requiring additional terraforming at the least
- the wall would take me weeks or months to complete
- it would be less expensive to have my entire hill side flattened out then to build a wall. Thus giving me 10 times as much flat space as the wall would have.

Thanks for all your help. I'll be doing some smaller projects this weekend. I've given up on this bigger wall, but will probably do some other smaller ones. *trucewhiteflag*

DVS Hardscaper
05-23-2012, 01:44 PM
We get a lot of calls for walls and we build a lot of walls.

Sometimes people say "we need a wall becuse we're tired of mowing this hill". Fact is - they can pay a mowing company to mow the grass for the next 10 yrs and it will be less money then the wall.

If you do end up doing grading, yes you can place fill over the existing drain field. But you may also hinder the area designated at your back up drain field. Which could pose a problem when your current field fails.
Posted via Mobile Device

SSmith
05-23-2012, 05:21 PM
I'm just glad that I was able to deter a potential nightmare for this nice engineer from NKY. Think about how many people don't consult professionals before undertaking such a project. I don't like to see anyone get in over their heads and cause undue physical/mental stress. I'm the hardscaping Mother Theresa, I guess.

blkhawk661
05-24-2012, 10:08 AM
If you do end up doing grading, yes you can place fill over the existing drain field. But you may also hinder the area designated at your back up drain field. Which could pose a problem when your current field fails.
Posted via Mobile Device

thanks. I will keep drainage at the forefront of my mind. The landscaper who suggested this seems very knowledgeable and I trust his expertise, though i will push him on drainage.

He was the one who pointed out to me the wall was in a drainage field and that i probably didn't have ideal grading away from my house.

blkhawk661
05-24-2012, 11:38 AM
I'm the hardscaping Mother Theresa, I guess.

Thanks mom :)