Retaining Wall question

[RibbleConstruction]

Hope this is the right spot to post this.
I rarely do retaining walls. Almost always contract them out. Long story, but I cant contract this one out. Home owner wants me personally to do the work. So can someone tell me how to do it?
It is right next to a driveway, and he will be parking his car there. Its 32 feet long. And it starts out 34 inches tall. And for the first 12 feet it stays 34 inches tall. And then it tapers down to nothing. I would assume I need to bury one full coarse and set it on about 6 inches of crushed rock. Then would I put some kind of drainage rock behind it? Would I need a draintile? The space behind it is gettin 10 feet wide of 6 inch deep one inch rock. Any Advice?

[Big Dog D]

What type of wall? Block, Stone, Timber?


Is the parking area being held up by the wall? Or is the area being held back from the parking area?

[RibbleConstruction]

block 18x12

[RibbleConstruction]

The parking is held up by the wall.

[Big Dog D]

block 18x12



What type specifically? It makes a difference.

[GMC Driver]

If you are using a manufactured concrete retaining wall product (you said block - 18x12) then use the following steps:

Excavate for base, plan on burying one course below grade. Blocks interlock from course to course? Some of the walls we use have a pin system, or clips. Place base course on a level compacted aggregate base, aggregate used here is a 3/4" crush and run. Make sure next course(s) incorporate some sort of a setback per course - dependant on what the product is. Be sure to place geo-textile fabric at the back of the wall, and along the back of excavated bank. Be sure to bury weeping tile along the base of the wall, with an outlet for moisture. Backfill with a clear granular to allow drainage. For wall systems that require a grid/mesh tie-back system, be sure to place at the reccomended heights/courses.

Some extra things that may want to be considered - use a high quality adhesive for corners and coping/cap stone. Granular backfill should be compacted at regular intervals.

If I missed anything, I'm sure someone will chime in - Matt!!! When are we supposed to start in Erie?!?

[2_DJinn]

Without knowing what kind of block you are working with i can only offer some broad advise. I used the use fabric and #73 limestone ( base stone, i know everyone calls it a lil different in different regions ) in the past however due to small issues and the quest of delivering a higher quality product ive gone to pouring a footer. Saves time and manpower once ya look at the time you spend messing with the stone , leveling ect ect. Just something to think about.


While this isnt a tall wall it will still carry a load and you will want to use geo grid (however you already know this..lol )

When working with a type of block that you dont have experience with most mfg's will send out a rep that will work onsite with you and more times then not show ya some tools and tricks that make life easier.

Note- All the block and stone reps have been great however the James Hardie siding rep knew way less then we did and all we got out of it was some cool tools , hats and hoodies.

Just a few points to think about.

[MDsnowPRO]

I agree with everything GMC Driver said, kinda took the words right out of my mouth

A few tips for concrete block walls.

Level is so important, check each block as you go.
Good compaction is a must or the wall WILL fail!
If possible get a engineer to look at the wall site. With the height of this wall being under 36in that may not be needed if the site is pretty normal traffic, drainage and layout wise.
Look into the geo-grid product from US Fabrics.

http://www.usfabricsinc.com/products/geogrids.shtml

I have used the Uniaxial GeoGrid many times with great results.

[RibbleConstruction]

http://www.reimerskaufman.com/reimers_kaufman/products/segmental_retaining_walls_anchor/residential/anchor_diamond


Those are the blocks I am using. I figured I would use a 6 inch base of crushed concrete fill. Since the wall is basically 3 feet tall at the tallest, I dont think I need an engineer. However, It will need to carry a load. It is right next to a residential driveway, in which he parks a buick lesabre daily. Right now he has railroad ties there and they aren't doing the trick. I though I would dig them out and start all over. I figured a good base was the most critical step. The biggest question I have is the drainage issue. What do you put behind the wall, pea gravel? Thanks for your help guys.

On a side note, we had a similiar experience with our Hardi rep too. We even showed him a few tricks.

[Alan]

Those blocks are virtually identical to the Rockwood "Garden Wall" in both size and appearance.

Will the car be parallel to the wall or nosed up towards it? If it's parallel then it's probably safe to assume it is parked far enough away so passengers can enter/exit.

I think,, and this is going from memory that Rockwood says 3' max before you need grid on those blocks. Personaly I don't like that design if you're going over 3-4 courses,,,, that's just my gut reaction,,, you're depending on the rear key to hold it all togehter.

Is your soil a type that changes volume a lot with moisture changes? That a can be a big factor in the pressure on the wall. A soil that expands has a lot of force, that might explain why the timber wall is going west.

I think I'd want more than a 6" base,, again,, just my opinion. Bury at least one course of block. Behind that wall I'd use what we call "Inch minus", 1" down to maybe 1/2" crushed stone. Stay away from round stone, it doesn't chink at all well. Run a drain down at the base and daylight it. Leave plenty of room for stone when you dig.

For the parking area I would not use the 1" stone. If that's what I'm thinking it is, graded stone of a uniform size it's going to let water soak down behind the wall. I wish there were universal names for this stuff, around here it's either "Plant Mix" or "O5A" in a coarse grade or it's a finer material usually "Shur-Pack" or "#2 Stone". Both of those are mixes containgin either 1 1/2" down to dust or 1/2" to dust sizes and they pack hard. The coarser material is more resistant to getting mushy when the frost comes out. The finer is easier to grade smooth and generally looks better. Standard practice is 6-8" of coarse with a 2-4" layer of the fine on top. The compacted result will shed water pretty good, not 100% but still enough to keep it dry behind the wall.

I'd fill behind the wall to all but the last course of block with 1"- and then use filter fabric on that and finish off with either of the road stone mixes. 1"- won't compact for the most part, and even if it did I would not want to run a compactor right behind that wall anyhow.

Whatever you use behind the wall needs to have enough void area so that it will not retain water. Anything that is compactible is not going to meet that criteria.

If you want I'll try to find my Rockwood CD and try to find their specs on that similar block.

[Chuck Smith]

I wish there were universal names for this stuff, around here it's either "Plant Mix" or "O5A" in a coarse grade or it's a finer material usually "Shur-Pack" or "#2 Stone". Both of those are mixes containgin either 1 1/2" down to dust or 1/2" to dust sizes and they pack hard.

Here it's called QP (Quarry Process).

~Chuck

[MDsnowPRO]

As far as drainage, we use rigid pvc with holes in the top of it (face the holes down). We wrap the pipe with a sleeve made of landscape fabric. The fabric keeps soil from entering and clogging the pipe. I usually make the highest point of the pipe in the middle of the wall and then slowly slope it down in both directions towards the ends of the wall. At the ends we ether day light the pipe with a pop-up emitter or work it into a drain well.

[4evergreenlawns]

How did your wall turn out. Any pics??

I have some ideas and suggestions but to be honest I have a question.

Why would you even think about doing a wall install under these conditions without having the knowledge and or experience?

I can hardly think your client who wants you to do the work personally would feel the same way if they knew you were looking for advice on the internet.

I truly respect the fact that you openly admit you contract out most of you wall work. I guess it is because you do not have the experience or you would already be doing it yourself.

The first thing I would have done would be get my local outside sales rep. to come out and look at the job and then have him tell me how the Manfacture of the block I was going to use wants the block installed. Then I would follow those directions to the letter. If you wre going to upgrade the install like lets say put drain outlets every 5' in stead of every 10' like most manfactures require. I think you would be safe. But for my first couple of wall job I did exactly as I was told and based all future job off that model so I knew how to cost the project correctly.

No one here with all the expereince in the work can tell you how to install the wall without have expereince with the soil content, conditions, actually Sq.Ft. of load, and block manufacture being used.

Being SRW certified I still ask for help in the design phase of most walls I do. Now with that being said the walls we are installing are load bearing walls over 4' tall and usually over 50 linear feet. They have arleady been engineered and have minimum specs. So the method of construction although most steps are basic change from location to location and usage. I might be doing two walls of similar specs but two totaly different type of construction.

Furthermore, ANYTIME you do an install and do not follow the manufactures spec for that install you own the wall, and any damages that result. This season I have done two repairs on structural walls and in both case the wall were less than a year old and the original installer was charged back for the repair. If you build a wall and it comes down due to faulty install why would the property owner allow/authorize you to perfrom the repair under warranty??

So again I have to add I am talking about commercial work and I realize residential clients might not be so demanding and somewhat more understaning, but this is not the case when you do a commercial job in the 10's of thousands of dollars.

I truly hope your project went off without a hitch. I am not sure how long you warranty your walls but we do a 5 year warranty. You can bet I do not want to be returning or getting a call about a section of 10' x 100' wall came down 3 years after the install. Good luck and if you want to start taking on these type of project the $$$ is great but you might want to get some training to aviod having something come back and bite you in the arse later.

Not ure it is what you wanted to hear but maybe you can take something away from this that you have not already considered and add value to your business from it.

Best, Ron G.

[hlntoiz]

Dave (GMC Driver) is right on.

Most important factors:

Because the wall is holding up a driveway, a 3' wall must have geo-grid. Engineered or not. It dosn't hurt to spend a little extra to over beef the wall. Even at 3' the weight of the vehicles will have a temendous surcharge on the wall. At least 2 rows of grid. at 1' and 2' at least 3' into the bank. Stay level course by course. if you are off a 1/8" on the bottom it will multiply by the time you get to the top (even on a 3' wall) But most important you must back fill at least a 1' behind the wall with crushed stone. This will provide drainage and prevent the wall from "pushing" over from frost.


Hope my $.02 helps:grinz I have a tendency to "over build my walls" but I know they will last for ever.

[PSDF350]

How did your wall turn out. Any pics??

I have some ideas and suggestions but to be honest I have a question.

Why would you even think about doing a wall install under these conditions without having the knowledge and or experience?

I can hardly think your client who wants you to do the work personally would feel the same way if they knew you were looking for advice on the internet.

I truly respect the fact that you openly admit you contract out most of you wall work. I guess it is because you do not have the experience or you would already be doing it yourself.

The first thing I would have done would be get my local outside sales rep. to come out and look at the job and then have him tell me how the Manfacture of the block I was going to use wants the block installed. Then I would follow those directions to the letter. If you wre going to upgrade the install like lets say put drain outlets every 5' in stead of every 10' like most manfactures require. I think you would be safe. But for my first couple of wall job I did exactly as I was told and based all future job off that model so I knew how to cost the project correctly.

No one here with all the expereince in the work can tell you how to install the wall without have expereince with the soil content, conditions, actually Sq.Ft. of load, and block manufacture being used.

Being SRW certified I still ask for help in the design phase of most walls I do. Now with that being said the walls we are installing are load bearing walls over 4' tall and usually over 50 linear feet. They have arleady been engineered and have minimum specs. So the method of construction although most steps are basic change from location to location and usage. I might be doing two walls of similar specs but two totaly different type of construction.

Furthermore, ANYTIME you do an install and do not follow the manufactures spec for that install you own the wall, and any damages that result. This season I have done two repairs on structural walls and in both case the wall were less than a year old and the original installer was charged back for the repair. If you build a wall and it comes down due to faulty install why would the property owner allow/authorize you to perfrom the repair under warranty??

So again I have to add I am talking about commercial work and I realize residential clients might not be so demanding and somewhat more understaning, but this is not the case when you do a commercial job in the 10's of thousands of dollars.

I truly hope your project went off without a hitch. I am not sure how long you warranty your walls but we do a 5 year warranty. You can bet I do not want to be returning or getting a call about a section of 10' x 100' wall came down 3 years after the install. Good luck and if you want to start taking on these type of project the $$$ is great but you might want to get some training to aviod having something come back and bite you in the arse later.

Not ure it is what you wanted to hear but maybe you can take something away from this that you have not already considered and add value to your business from it.

Best, Ron G.

Not trying to stur the pot here, but you say dont do without experiance. But then go on to say my first couple walls. Everyone needs to start somewhere.

Sorry but it aggrivates me when people want to tell someone not to do something just because they have never done it before. Then turn around and talk about the first time they did there own. I have done many things I have never tried before, some came out great with little effort. Some came out exceptable with alot of trial and error. Just because someone doesn't have experiance does not meen they shouldn't do something. What a sad pathetic world this would be if no one tried anything they had never done before.

Now I am not saying jump in without research (which he is doing) or talking with a engineer if necissary(sp) or others in the know. Common sence will get you along way.

Good luck on the wall.

[4evergreenlawns]

David,

I possed some questions. Yes, I started somewhere, a couple of years ago. My first wall was not a load bearing structarual wall.

Even now I still seek addtional information on each and every wall job I do. I also offered some ways to get the expereince needed. Nowhere did I ever say DO NOT DO THE JOB or DO NOT EVEN THINGK ABOUT DOING IT.

Did you miss the part about walls that I have repaired due to others not doing a proper install?? So I would say that maybe I do have expereince in starting out somewhere and developing into a guy that is fixing others mistakes. Might just give me the background to offer some advice that is helpful to someone actually doing a wall job.

It also pisses me off that the indusrty is full of companies that just go out and practice at something and call it a professional job. So much as it is needed for people to TRY NEW THINGS it is equally important for compaines to give their client a realistic view of their capabilities. I know nothing about wood work or cabinet building and if one of my clients was really happy with a brick job and asked me to re-finish their cabinet I would not come to the Cabinet builders forum and ask for advice after committing to a job I have no idea about.

So your statement about common sence applies, if you are going to try something new learn about what you are doing before you go out and sell a job.

Did I miss where you offer any advice about building the wall, not to stir the pot. IF you read what others have offered you can see there are many differnt views and experience level. I can tell you that Anchor (the block manfacture he listed he was going to use) does not REQUIRE GEO-GRID on anything less that 4' and that is the engineering spec on GEO GRID, BUT I TOO WOULD USE GEO GRID as other reccommended IF it was feasable, BUT no one has told him how to install the GEO GRID.

Futhermore, how much projection is between the driveway and the wall? Is there even enough room to propoerly install the GEO GRID? Take into consideration GEO GRID is just ONE of many factor that need to be taken into consideration.

So no matter what anyone here offers as advice without knowing the experience level of the installer, the actaully condition of the job site what good is it really. That is why I reccommended to get someone local to look at the job and tell him exactly what needed/should be done to PROPERLY install that wall. Maybe even get the guy he usually contracts out to do the work to give him some tehc help, BUT why would the guy have any interests in teaching the guy that is hiriing him to do the work in the first palce other than putting himself out of business.

I am just no sure how you read what I posted and get I am telling him NOT NOW NOR EVER should you try to install a wall.

[RibbleConstruction]

Ron
First off, why would I not take work? I dont care if I have never done it before. There is a first time for everything. The wall turned out great. I did a lot of research, and actually followed a step by step from the guy I normally use. The only reason I didnt use him was the client didnt like my landscaper. He had an issue with him some years ago. So he wanted me to do it.

How about this. (I am not bragging just stating a fact) I do quality work. If I cant do it right I dont do it. I dont advertise and most of my work comes from referalls. So I have a reputation for doing good work. So my client was confident I would do it right.

I way over built this wall. And I didnt make much money on it. The way I see it is I got paid to learn. I researched this a lot. And I talked to the supplier. I asked advice here because I know there are a lot of competent landscapers here.

I will try to get over and get some pics so I can post them. And I will never say no to work. Unless I know I cant figure out how to do it. Right or wrong I like what I do. And when I tell people no, it gives them a reason to find someone else.

[4evergreenlawns]

Well I am gald to hear the wall turned out and you did get the tech help you needed to be sure it will stay up. Over building in the begin and even today is the way to go. I know I do not want any of what I put my company name on to come down.

Again, I just stated I wanted to ask some questions. If you did you homework and did a quality job that your company will benifit from it.

I know what it is like to say NO to a client and think the guy they bring in to do the job that I said no to is going to seal my account. BUT, I also know that the Client, if they are worth having, will also respect me much more for stating "My company is not in a position to do that just yet, BUT here is a guy that I can refer". I have done it over time and as I have grown I have taking on the work I know I can handle. Sometimes you have to turn work away. It hurts but not as much as when you fail should that happen.

The service I do provide speaks for itself. If I have a maintenance contract with a client it does not mean I automaticly get any other type of landscape work nor do I think I am owed it. I never over extend myself by implying that I can do something I can not. When I see the opportunity to do more work I seak out a chance to earn it. I never forget the primary reason why I am on the property in the first place is the exisiting contract and those services come first. I have replaced other contractor that see the big $$$ jobs and than slack on the maintenace. Maintenace is re-occurring and keep the $$ come in season after season. A brick job, pond, plantings, and so on are a one time hit. I never saw any bennifit from risking the maintenace contract to do a one time job if I was not in a position to do it just as good as the maintenance.

I do feel I offered some good advice and I know I had to learn too. In the off season I go to as many Training courses as I can and I earn all certification that are offered.

I want to be sure I know what I am doing and I want to be sure that when I give a Client my word that the job can be done by my company I can stand behind it for years to come. I have worked hard to earn the reputation my company has today. I am will not compromise that for anyone, anything, or any price, ever.

Good luck in the future. :cash :cash :cash :cash

[Chuck Smith]

Somewhat on topic. This has nothing to do with the wall, just that sometimes we as professionals have to say no to the customer. I had a guy come into the shop with a driveshaft off a tractor. A previous owner replaced the shear pin on it with a bolt much stronger than the pin. It was a square shaft for a PTO on a tractor, to drive a flail mower (only now it was round :D ). Customer wanted the shaft rebuilt. I told him to go to Tractor Supply and buy a new one. He said why, and I explained we can do it, but we can't balance it. He said it only runs @ 540 RPM (which I knew) so I tried to explain that it will eat U Joints if not balanced, especially being that it is always under constant load. He said he was going to the steel supplier and would be back. He never came back. I hope he went to Tractor Supply like I suggested, and not to some other welding shop who doesn't care and just did it. Either way in the end he will know I was right, and hopefully return with a job we can do. Like Ron said, I am not about to do a poor, half assed job for any price.


~Chuck

[RibbleConstruction]

Just because one is less experienced then others does not mean he will do a less quality job. I wont take something I cant handle. But When It came to this wall, I was pretty sure I could handle it. Not to mention, If I learn on this one then maybe I can do another one in the future. I have told customers no. And I normally try to get bigger jobs then this one was. But because of my relationship with this customer I felt like I could offer a quality job, and he would be happy with. I told him right from the start that this is not something I do regularly. And that I had someone else I would like to recomend. He asked me if I could bend the rules and do it myself. I told him I would. I have enough of a background in this type of work to know how to do it. But, I thought I would come here to get advice from guys that do it all the time. Figured it cant hurt to ask. Now if this was a taller wall, or a lot longer. Or signifigantly more structural I may have passed. But a wall that is a total of 100sqf is a good place to start.