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Thread: Retaining Wall...

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    Casey's Avatar
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    Retaining Wall...

    Hi Guys n' Gals!

    I would like some input on my new yard... Just so happens I live on a hill and I really want to put up an above ground pool this summer. I'm adding some pics for your opinion. You have all been so very helpful in the past so here goes...

    This is where I'd like the pool. It's really the only place I can put a 24ft round agp.


    Here is a look from the road...


    What do you all think? Retaining wall or not? Need more info, just ask and I'll try to answer...
    I'd bet you my bikini you'll never get TFP water from a pool store!

    24' Sharkline Venture De Filter

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    JasonLion's Avatar
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    Re: Retaining Wall...

    Yes, I'd say you are certainly going to need a retaining wall. You are actually likely to need two, one above the pool and one below. You will probably need a soil engineer as well, to confirm that the retaining wall design is sufficient to prevent the pool from sliding down the hill.
    19K gal, vinyl, 1/2 HP WhisperFlo pump, 200 sqft cartridge filter, AutoPilot Digital SWG, Dolphin Dynamic cleaning robot
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    Re: Retaining Wall...

    Hi, Casey,

    How ya' doin'? It's good to see you on the forum.

    Yeah, Jason is right. That is a pretty darn steep yard and it will take some modification (walls) to make it workable. Like everything else, it can certainly be done at SOME price. It may end up a little pricey.
    Dave S.
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    Re: Retaining Wall...

    I'm doing well Dave! It's been awhile but I've been lurking... I want a pool but this hill seems to be in my way!

    I did figure I'd need a retaining wall. Looks like I'll be busy! My first initial thought was two walls too. I certainly don't want to be floating on a raft going down the hill at 100 miles an hour through town!
    I'd bet you my bikini you'll never get TFP water from a pool store!

    24' Sharkline Venture De Filter

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    Mod Squad Bama Rambler's Avatar
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    Re: Retaining Wall...

    Pictures (and even eyesight) can be very misleading when it comes to guessing grades. However, you're probably right about the two walls. The good news is that it's definitely doable.
    Dave J. TFP Moderator
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    Re: Retaining Wall...

    My back yard is no where near that steep for that distance..........and my AGP is 16x32 with the 16 ft running perpendicular across the grade of the slope. My pool is dug down 2 feet on the high side of the slope............and 16 feet further down the grade............it is only about 1 foot dug down. Just an option to consider if it could possibly work for you. 24 feet stretched out across that grade is a whole lot different though. Maybe a combination of digging down on the highest side to minimize the height (cost) of the retaining wall(s) Good Luck!
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    Re: Retaining Wall...

    Quote Originally Posted by Bama Rambler
    Pictures (and even eyesight) can be very misleading when it comes to guessing grades. However, you're probably right about the two walls. The good news is that it's definitely doable.
    I know it's doable. My chains have been grinding for a year now just thinking about "how" I want to do it. I definately want to do it myself to cut down the cost and installing the pool myself too.

    There is no way I'd venture on putting an end stamp on this as it may take me awhile. It'll be an after work/weekend project. I can invision the end result in my mind though... It looks nice!
    I'd bet you my bikini you'll never get TFP water from a pool store!

    24' Sharkline Venture De Filter

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    Re: Retaining Wall...

    Hi Casey

    What you want to do is called terracing. The idea is to make a flat, level surface that you can set an above ground pool on. How big that level pad is will be dictated by how big you want to pool to be and if you want an area large enough for a deck of some type or sitting areas, etc. I think everyone so far has the right idea. Two walls will be needed to do what you want; one on the high side, one on the low side. The way to do this is to dig down on the high side and build a wall to hold that material back and build another wall on the low end so as to make the level pad. How deep you dig on the high side and how high the low side wall needs to be will be determined by how much fall there is where you want to put the pad.
    My situatiion was pretty similar. Even tyhough I have an incround pool, i still had to make a level pad in which to sink the pool. Below are a couple of pictures on my back yard before:




    What we did was to build a curved wall on the back of the low side like this:


    Level a pad and sink the pool (yours would be a flat pad to set an ABG pool on):



    Then build a wall to hold back the soil where we dug down the high side:




    Now mine as a lot of extras with multi tiered walls, steps, etc that you really dont need in your case to get the desired terrace, but you get the idea. One wall on the high side, aand one on the low side (probably curved to maximize the space) to make a flat area for the pool.
    14,000 gallon IG, Vinyl. Hayward 3/4 hp superpump, Penatair IC40 SWCG, Pentair automation, Hayward sand filter, Aqua Comfort heat pump, Hayward 400k Lo-Nox LP heater.

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    Re: Retaining Wall...

    Quote Originally Posted by Casey

    I definately want to do it myself to cut down the cost and installing the pool myself too.
    HHMMM. A DYI wall like what you will need will be tough if you've never done something like this before. It's doable DYI, but there is a lot , and I mean a lot that will go into it. It's not as simple as putting in stacked blocks. Digging footings, bringing in stone for the footings, getting the base course level, potentially getting the bottom wall engineered, using geogrid if you need it. Like I said, its doable DYI, but man it'll be a challenge.
    14,000 gallon IG, Vinyl. Hayward 3/4 hp superpump, Penatair IC40 SWCG, Pentair automation, Hayward sand filter, Aqua Comfort heat pump, Hayward 400k Lo-Nox LP heater.

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    Re: Retaining Wall...

    I just got done doing a DYI wall with two terrace's required due to the slope. My slope doesn't appear to be as dramatic as yours but you will find out very quickly how much you'll be working with when you start digging. My recommendation is that you can certainly do it yourself, but without equipment, it is much more labor intensive. Also, you'll be spending a lot of $$'s on block wall. Here are pictures from mine: new-pool-construction-t28608.html
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    Re: Retaining Wall...

    Thats a nice looking wall! Who's system is it? I used Versa Loc. Does yousr use pins? I dont see any holes for them. Did you have to use any grid?
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    Re: Retaining Wall...

    Belgard Celtik wall, probably the most expensive wall you can get. If I knew the wall was going to be that big, I wouldn't have done it with Celtik due to cost (over $20K in material including stone). It's got pins on the bottom that rest behind the block below it. I did use geogrid on the walls. I had over 2' of gravel behind the walls, so I would suspect I wouldn't have had to use geogrid, but it's a cheap addition. It's done well through this harsh winter so far with all our freezing and I've got a grade where I'm probably getting a substantial amount of water coming my way. Got a lot of drainage in front and behind the bottom wall and behind the top wall.
    18 x 36 Inground Gunnite, White Plaster 21K gallon
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    Re: Retaining Wall...

    Yea, the Celtik is kind of expensive. The Versa Lok works pretty much the same except the plastic pins go in the middle. The walls i have went on 2' deep footings filled with 3/4" stone and back filled with about 2' of stone as well. The geogrid was used on anything over 3 feet tall (which was most of it). We put a french drain in behind every wall wrapped in filter fabric. On the big wall in the back, we ran the french drain out the base of the wall at the lowest point. In 3+ years, I've never seen the pipe wet yet. The key to the geogrid on a taller wall is to use a compactable material to put the geogrid in. I've seen walls that were 5 feet high that were bowed a little because the geogrid was in pure stone. With a high wall you need a more compactable material to hold multiplem layers of grid tighter. That back wall behind the pool was engineered. The landscaper that built it knew what need to be done, but the permit for it required an engineer to sign off on it. I have almost a 1000 sq feet of versa loc back there. Bought and installed it was about $32 a sq foot. Do the math
    Yea, well built retaining walls are expensive. Your Celtik and my Versa lok will be there after the house falls down! I thought about building it myself, but we were anxious to get the pool in, I had the money, and I wasnt too keen on lifting those 80 pound-a-piece blocks!
    14,000 gallon IG, Vinyl. Hayward 3/4 hp superpump, Penatair IC40 SWCG, Pentair automation, Hayward sand filter, Aqua Comfort heat pump, Hayward 400k Lo-Nox LP heater.

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    Re: Retaining Wall...

    HI CASEY

    I hope you know how much I want you to be able to have another pool!

    Though I don't know the comparative prices, I want to mention the option of concrete retaining walls. Given the time of year and the economy, a small, 1-3 man company, might rent you the forms you'd need or do the job for a discount/ reasonable price. [I've worked for a couple of them over the years]

    I truly hope that you and yours are well
    Luv& Luk
    -Ted

    Having done construction and service for 4 pool companies in 4 states starting in 1988, what I know about pools could fill a couple of books - what I don't know could fill a couple of libraries :-D

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    Re: Retaining Wall...

    You could try a concrete wall. But, concrete wont last. It will be ok for a couple three years or so, then it will start to break down and eventually it will fail in that application. A pinned wall or stone mason wall is about all you can do for a wall that will last over time. There is too much weight to use concrete. The top wall would most likely work just fine using concrete, but a bottom wall needed to hold up all that weight wont stand over time.

    Before anybody points out basement or celler walls are made of concrete, thats very true. The difference is that there is a framed structure that spans the basement that helps support everything over time. For a stand alone concrete wall, the hydrostatic pressure will push it over after a few years and it will fail. The only way you could possibly do concrete is to have it engineered, and even then its a **** shoot. A concrete retaining wall is not a DYI job for this application.
    14,000 gallon IG, Vinyl. Hayward 3/4 hp superpump, Penatair IC40 SWCG, Pentair automation, Hayward sand filter, Aqua Comfort heat pump, Hayward 400k Lo-Nox LP heater.

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    Re: Retaining Wall...

    Quote Originally Posted by waste
    HI CASEY

    I hope you know how much I want you to be able to have another pool!

    Though I don't know the comparative prices, I want to mention the option of concrete retaining walls. Given the time of year and the economy, a small, 1-3 man company, might rent you the forms you'd need or do the job for a discount/ reasonable price. [I've worked for a couple of them over the years]

    I truly hope that you and yours are well
    Hi waste!

    I've thought about them and I've also thought about railroad ties. I'm thinking of every option I have that will last and not cost me another mortgage.

    I have a couple guys calling me back wanting to do estimates too. *If you could imagine my thoughts on this right now, it would look like a 3" folder full of papers exploded!*
    I'd bet you my bikini you'll never get TFP water from a pool store!

    24' Sharkline Venture De Filter

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    Re: Retaining Wall...

    Quote Originally Posted by Casey

    I've thought about them and I've also thought about railroad ties. :
    Not to be a party pooper, but that really wont work. Gravity will pull those down really, really fast. Unfortunately, a retaining wall on that kind of grade is pretty complicated and expensive, if done properly. At the least it needs to be engineered by a professional. You need someone who knows how to shoot grades, excavate properly, and put in the footing. If you had a less steep grade it wouldnt be as complicated. With that amount of fall, without a pinned wall with geogrid, gravity will take it right down the hill.
    14,000 gallon IG, Vinyl. Hayward 3/4 hp superpump, Penatair IC40 SWCG, Pentair automation, Hayward sand filter, Aqua Comfort heat pump, Hayward 400k Lo-Nox LP heater.

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    Re: Retaining Wall...

    Like I said... I'm just thinking right now... just so happens to be out loud at the moment.

    I had a couple people call me today that want to come out and see what I've got. I'm sure they will be itching to jump all over it.
    I'd bet you my bikini you'll never get TFP water from a pool store!

    24' Sharkline Venture De Filter

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    Re: Retaining Wall...

    Its hard to tell from the pictures what your slope situation is like. Ideally, using a bobcat, you could push some earth down to create nice level, maybe 40' diamater "pad". The the retaining wall would hold the new earth back.

    With that said, I strongly second the idea of using engineered concrete block. Versa lok, mentioned above, is one manufacturer, probably more reasonable than Belgard. Whats more important is what brand you can buy locally. There's a lot of brands so visit your local garden centers/landscaping stores. Try to find the ones that sell plenty of landscaping supplies.

    I built a 60' x 4' wall behind my pool with this system. Its labor intensive so you'll need some hired help. But its not as complicated as it sounds (assuming your a little handy). This pdf kind of shows it all: http://www.versa-lok.com/sites/default/ ... ection.pdf. You need to factor things like fill dirt, rock, drain line, and equipment rental (tamper, bob cat, etc...).

    Since your wall will be taller, and its a new install you'll definitely need an engineer to come up with a plan.Some companies will work with you to create a plan that all you need to do is have a local engineer approve (disclaimer: that may only be for smaller jobs).

    When I did the math, this was definitely cheaper than concrete. But maybe concrete prices are cheaper in your area? Thing with concrete is you have to build the forms, make sure the mix is correct, etc....not very diy friendly.

    Check out some photos of larger walls at Versa Lok....http://www.versa-lok.com/. Not endorsing this company, just showing an example


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