Retaining Pool Walls

[mentalscastle]

So my backyard has this ledge and not the biggest backyard so the idea was to have the pool also serve as the retaining wall along with the infinity edge which will need the return which will also go further back and lower ultimately serve as a retaining wall. Would love your thoughts on the design. Do you see this being a good idea, problematic or any other suggestions here as I am a first timer.

Here are pics of the original property as it is now along with my renders, keep in mind the return will not be that open.

 

[Blackdirt Cowboy]

I am just starting construction in a yard similar to yours. We are putting a retaining wall between the house and the pool. The pool surface will be on a lower plane than the house. The lower pool wall will be about 2 feet out of the ground. We don’t have an infinity edge, but we will have a deck below the pool. Your house is constantly trying to push its way down the hill. I certainly feel more comfortable with it trying to push on the retaining wall versus pushing on my pool.

 

[JoyfulNoise]

Be very careful with the engineering of these infinity edge pools. If you don’t balance the flows correctly and make sure the long walls are extremely level, the effect you’re looking for will not happen. You also need to make sure the exterior walls and capture basin are completely waterproofed and sealed with some kind of fascia (plaster, tile, stone, whatever) as concrete is not water proof. You will get a lot of weeping and efflorescence if this is not properly executed.

Calling in @setsailsoon who just completed a GORGEOUS infinity and zero edge entry pool build. Also calling in @JamesW for hydraulic design.

 

[mentalscastle]

Also in terms of references should I ask to visit these places and talk to the owners. Not sure how far is over stepping the line. I am honestly down for anything since this project is going to cost a lot.

 

[JoyfulNoise]

What you’re showing is a very high-end pool, 6-figures easily. This is not a pool that can be built by a novice builder. You are going to want someone that knows how to build these types of overflow pools and has the references to back it up. You are going to want to find at least three builders to get quotes from and you are going to want to provide them with YOUR design and requirements so that they are all bidding on the same specs. Otherwise you’re going to get apples-to-oranges comparisons. Once you lock-in on a builder you think you can work with, you are going to want references, at least three builds. I suggest asking for both recent references and older ones so you can get a feel for how their work has stood the test of time.

Good luck. The bidding process is going to take a lot of work. Be careful of slick-talkers promising you the moon and the stars … lots of good people in the business but definitely bad apples too.

 

[mentalscastle]

Thanks soo much for the advice for sure. It is in the six figures for sure. I did some research on the company as well and even had my lawyer do the same. They been around for over 30 years. The company also offers a lifetime warranty as well as long as they open and close the pool. The line item where they mention retaining wall that was something separate if we were going to have one on the left and right of the pool back there. Would love your thougths on this too. Once again thanks soo much and I am loving the community on here, this is really special!

 

[Buggs]

What you’re showing is a very high-end pool, 6-figures easily. This is not a pool that can be built by a novice builder. You are going to want someone that knows how to build these types of overflow pools and has the references to back it up. You are going to want to find at least three builders to get quotes from and you are going to want to provide them with YOUR design and requirements so that they are all bidding on the same specs. Otherwise you’re going to get apples-to-oranges comparisons. Once you lock-in on a builder you think you can work with, you are going to want references, at least three builds. I suggest asking for both recent references and older ones so you can get a feel for how their work has stood the test of time.

Good luck. The bidding process is going to take a lot of work. Be careful of slick-talkers promising you the moon and the stars … lots of good people in the business but definitely bad apples too.

Looking back at our build, Newdude's advice is spot-on. We built our pool along the edge of a 40º slope. We didn't want it to crack or shift in this earthquake-prone area. We hired an engineer to design the foundation. Our builder does a lot of commercial pools and was the prime contractor on our regional waterpark.

The lower patio is actually a 2nd foundation to support the primary. The base of this lower foundation begins 24' below the water level. The waterfall header tank is buried in the hillside.

A quarter-century later, it is still in great shape. If you're going to do it - do it right!

 

[mentalscastle]

WOW! What a beautiful pool!!!!!!! And the infinity edge never needed any work done over the 25 years to make sure it has that edge still. I figured if one little thing is off it wont have that look. More questions to come.

 

[JoyfulNoise]

Chris’s thread is here -

16 July 2024 Finishing Up my OB Pool

As the original post states, the first 30 pages are his custom home build and the last 36 pages or so are his pool build. The finished product is amazing. The pool build contains A LOT of specific information on how he went about his owner/builder process as well as the detail specs for his overflow. His pool is both a zero-entry pool with perimeter gutters to channel water to the overflow basin as well as an infinity edge along the west facing wall. It’s a huge run length that requires a commercial grade 5HP pump to give enough flow and the edge is level across the entire span. If you want something to read, that’s the thread I would send you too.

 

[setsailsoon]

M,

Been perusing this thread for a few minutes and need to do a lot more but here are a few initial thoughts:

• Gorgeous concept, I have a thing for infinity pools and would even go further to incorporate a zero edge. It would look great on your property.
• You have a LOT of civil work to do outside the pool. The contractor only does rough grading 4' outside the pool.
• The civil work includes a very long retaining wall that is going to have an interface with the pool structural work. Ideally a single structural engineer would do the whole thing. If that's not possible both engineers should accept the interface details of the other's.
• Things I liked about this proposal:
  • Some of the pricing details seemed pretty reasonable to me such as the automation being a $3500 adder, engineering/design are similar to mine for similar pool, well points.
  • I liked that the PB identified a lot of extra cost items and many, maybe all will apply to your build.
• Things I didn't like about this proposal:
  • Project progress terms are unacceptable. You are required to pay each one before the milestone is achieved with no reference to the quality and how to measure the milestone.
  • Warranty has hooks in you for services you have to purchase from them and there's no reference to what these will cost
  • They seem to define very clearly their scope included and at a minimum what your costs will be. Prices for extras have a huge premium. For example, $200/hr for extra excavation sounds OK until you realize that's $1600 per day then another $1500 (or $1600 in the fine print) for hauling not including the dumping fees. Wouldn't surprise me at all if you had 4 loads of haul out. By the way, get them to define how large a load is.
  • Hauling off fill is 4 times what my cost was including dumping fees and the proposal does not include dumping fees.
  • I don't see any specifications for quality. For example, elevation variance along your rather long infinity wall. As Matt mentioned this is critical.
  • I think you're gonna need a bigger pump. @JamesW was kind enough to do this for my pool and I'm very glad he did. The water would barely trickle over with the original designer's 2.7 hp pump. I got a commercial grade 5 hp vs pump he suggested and the pool operation is off the charts spectacular. Your infinity wall is exactly the same length as mine.

I know this sounds sort of negative but you have to be skeptical. The fact these people have been in business for 30 years gives hope that you can negotiate a fair price for this job but this contract needs a lot of changes to make it something I'd sign. One think I've thought about is a slightly different approach for this job. Engage an engineer to perform the design directly with you so you own the design. Then allow PB's to bid. This allows you to get a lot of the uncertainties out and understand the full scope of the work. Have this engineer do the entire retaining wall and civil design for the rest of the dirt work. This allows you to optimize the overall project. There may be things you can do that might increase cost of one part but reduce the total. If you're open to alternatives you can let the engineer know this. For example a retaining wall may be one choice. Another may be a gradual slope to the back of the property with small retaining walls at each end of the basin to keep dirt out from the sodded areas.

I'll keep looking at this and add more if I find anything. In the meantime, please do keep us posted on this very interesting project!

Chris

 

[setsailsoon]

Chris’s thread is here -

16 July 2024 Finishing Up my OB Pool

As the original post states, the first 30 pages are his custom home build and the last 36 pages or so are his pool build. The finished product is amazing. The pool build contains A LOT of specific information on how he went about his owner/builder process as well as the detail specs for his overflow. His pool is both a zero-entry pool with perimeter gutters to channel water to the overflow basin as well as an infinity edge along the west facing wall. It’s a huge run length that requires a commercial grade 5HP pump to give enough flow and the edge is level across the entire span. If you want something to read, that’s the thread I would send you too.

Thanks for the kind words Matt. I'll also recognize the many TFP expert contributors that made it better.

Chris

 

[mentalscastle]

@setsailsoon first off I can't thank you enough for everything above. You're a true GEM!

Just a few things that were mentioned with my meeting with this company.

1. He suggested that the pool would be the retaining wall and we would not need one as we would use all the extra fill and pour it over the edges. As you did mention 4 truck loads, the good thing about living where I live as you can see in the aerial is I do own the property down the slope. Either way I am going to have a structural engineer come and see what is possible here as the contract states his engineer is only for the pool. With that said how wide do you think this retaining wall needs to be? The whole width of the whole cliff or more so around the pool area?

2. Also once they do provide me with referrals that I visit is it fine to ask them about how much over did they end up paying based off the original quote.

3. Even though they proposed around $130k without electrical, landscaping, masonry, surveys, etc. which will prob be around $160k or so how much over do you see this project being? My biggest fear/bad dream is they keep coming back saying we going to now need X and X to get this done week after week. I am going to have a lawyer red line the contract. Do you think it makes sense that they are responsible for everything they are proposing except digging up boulders which we know is both out of our hands.

Would love your thoughts. Sorry I sound super rookie.

 

[JoyfulNoise]

1. He suggested that the pool would be the retaining wall and we would not need one as we would use all the extra fill and pour it over the edges. As you did mention 4 truck loads, the good thing about living where I live as you can see in the aerial is I do own the property down the slope. Either way I am going to have a structural engineer come and see what is possible here as the contract states his engineer is only for the pool. With that said how wide do you think this retaining wall needs to be? The whole width of the whole cliff or more so around the pool area?

That sounds like a REALLY BAD idea. Whatever they excavate is going to be loose soil at best. It will have no compaction whatsoever and so it will not stay in place. The very next big rainstorm will see all that soil pouring down the hill. When the winter precipitation melts and spring temperatures rise, that loose soil won’t hold back anything.

Get a civil engineer to look at it. You don’t want to half-azz that part of the project.

2. Also once they do provide me with referrals that I visit is it fine to ask them about how much over did they end up paying based off the original quote.

Yes, absolutely. They don’t have to give you a detailed price breakdown but you should definitely ask them if there were any overages, change-orders, last minute screw ups, etc, that drove up costs.

3. Even though they proposed around $130k without electrical, landscaping, masonry, surveys, etc. which will prob be around $160k or so how much over do you see this project being? My biggest fear/bad dream is they keep coming back saying we going to now need X and X to get this done week after week. I am going to have a lawyer red line the contract. Do you think it makes sense that they are responsible for everything they are proposing except digging up boulders which we know is both out of our hands.

Typically you want to have a very well defined payment schedule that leaves AT LEAST 10% on the table until your final punch list is complete. The builder needs cash to pay the subs at certain points but you can ask that each payment be contingent on completion of the specific job when a quality metric has been met - “shell is fabricated, all measurements are within spec and level edges are achieved … etc, etc”. And you should insist on getting copies of all lien-releases for every sub that has completed their part of the job. You can consider using an escrow account to make payments but some builders prefer cash in hand … that’s a detail you can work out as long as all payments are documented.

Changes and unexpected surprises happen on any complex project. Communication is essential to cost containment. Make sure you establish good rapport up front with the builder and require them to be onsite for each major checkpoint of the project. Last minute change-orders are expensive and should only be considered if there is a really good reason to make the change.

 

[tgurske]

The nice thing about your area is that there is affordable stone everywhere. You might have to blast some away for that pool. And your soil might actually be clay. Make sure you find out what’s there before starting on any project and if it was my house I would prefer a stone retaining wall, resting on the stone under the dirt.

It is going to be nice though. Post pics when you do it.

 

[Bill1974]

Looks great!

Other than what has been said by others:
•Managing rainwater that falls between the house and the pool or come off the house is very important. You may need some minor swale or drainage in this area.
•Ensure the ground is stable and the slope in't going to move. Any movement will change how the infinity edge works.
•The location of the shower seems a little off with the bay window near it and no access to house, need to walk on the grass and no screening around it.
•Maintaining the grass between pavers and near the pool will be a challenge. Does the back of the house face south? Grass does not grow well if it is in the shade all the time or gets baked from the sun reflecting off the house.

 

[setsailsoon]

@setsailsoon first off I can't thank you enough for everything above. You're a true GEM!

Just a few things that were mentioned with my meeting with this company.

1. He suggested that the pool would be the retaining wall and we would not need one as we would use all the extra fill and pour it over the edges. As you did mention 4 truck loads, the good thing about living where I live as you can see in the aerial is I do own the property down the slope. Either way I am going to have a structural engineer come and see what is possible here as the contract states his engineer is only for the pool. With that said how wide do you think this retaining wall needs to be? The whole width of the whole cliff or more so around the pool area?

2. Also once they do provide me with referrals that I visit is it fine to ask them about how much over did they end up paying based off the original quote.

3. Even though they proposed around $130k without electrical, landscaping, masonry, surveys, etc. which will prob be around $160k or so how much over do you see this project being? My biggest fear/bad dream is they keep coming back saying we going to now need X and X to get this done week after week. I am going to have a lawyer red line the contract. Do you think it makes sense that they are responsible for everything they are proposing except digging up boulders which we know is both out of our hands.

Would love your thoughts. Sorry I sound super rookie.

Here are my thoughts on your questions:
1. Retaining walls I've seen are used for two reasons. One is to prevent erosion of soil when you have a steep slope. In my area that means more than 1' drop in 5' according to the building department guidelines. This probably varies depending on soil. Mine is 85% sand and remainder organics. The other place I've seen them used is to prevent material from contacting water like you have at the water edge. You see this a lot at docks where sheet piling is driven to prevent water from undermining the structure. It's important to know what you don't know and your idea to contact a structural engineer is a good one. That's what I'd do. They deal with this all the time and will help define alternatives that are structurally sound and then you can choose which ones look the best and/or are most cost effective for you. The engineer should be able to help on the cost side as well. It makes sense to me that the pool is a retaining wall since fundamentally the pool is designed to retain the wall. But what happens at the overflow basin (sometimes called a trough)? If you don't have some kind of retaining wall beside the pool you'll likely have dirt washing into the basin. I saw a LOT of this before I put in the short retaining wall at each edge. I'll send photos later today.

2. Definitely ask the references anything you want to especially about cost. I would also ask about the communications with their construction manager and how was he on site. The right answer is he should be on site every day at least to check progress/quality. It's way more cost effective to find/correct quality issues, compliance with design early. He should also be there for the entire time at critical junctures like layout of the pool, initial forming work, just prior to inspections, gunite, tile, plaster. If I'm paying a PB I want him to do at least what I'd do to manage the construction.

3. It's hard to tell what the final cost will be until you define scope. In your case the pool scope is partially defined and the rest of the job is not defined at all. I would get the pool scope completely defined and the rest of the scope that has to be done to complete your project. In order to develop your cost estimate you need two things nailed down:

• Scope of the entire job
• Basis of estimate (this describes estimate assumptions like weather impact, type of contract, wage scale, rentals, etc)

All this said, I think your costs could total a number that is $200K+. Rough estimates for a high end pool from a quality builder are about $320/sq ft. in my area. This includes about 40% gross margin based on my cost to build vs quote from them. This would be about $163k for your pool so this correlates to your $160K number. But I would caution when you have major open items like your scope has right now your estimate should be considered +30/-10 %. I know that sounds absurdly high but I will also tell you most of the time from this stage of scope maturity projects usually come in closer to the top of the range. This is why I think it's soooo important to mature your scope with more complete engineering to support the scope. What does that mean? Here's and example: you don't know what the scope is for the retaining wall until you do enough design work to find out what the options are that will work, what the cost, and what you like. Right now, your electrical design could be very standard or could require major changes if your current load is at the design capacity. Same for gas. If you don't want a spa, sundeck, or any other features your piping design allowances are probably good. I don't see anything locked in on your plaster selection but there's a big variance for type and even some colors. Automation appears to be selected so you're good there. Unless you decide you want state of the art and better future flexibility of an Intellicenter. Same for Jandy vs Pentair for several other equipment items. I could go on and on but this is what I mean when I say your scope is not nailed down yet. All of the impactful design disciplines need to be at least 50% complete before you can say you have a +10% estimate. This includes civil/structural, mechanical, electrical, instrument/automation.

I mentioned I'd keep looking at the contract and I've noticed some other things:

• Hidden conditions like rocks and boulders. These are always hard to deal with because nobody knows what's down there 'till they dig. You can get indications from engineers/excavation contractors with experience in your area. If you try to put all the risk of this on the contractor they have to guess high. Then you almost always pay way more than you should. I like to do the best I can to find out what's expected then lock in a reasonable "at cost" adder for extra time. Your quote attempts this but the adder isn't close to "at cost".
• I mentioned this before but it's so important I'll mention it again. The payment schedule is absurd. I'd never agree to this. You want progress payments to approximate work in place then have them earn their profit at the end after performance test is passed.
• The project schedule seems way too short. I worry this isn't really a high quality builder when they can start in 30 days. This indicates they have no backlog and that's not likely for the best builder in your area. Also, weather can have a huge impact to costs in your area. If this turns out to have design/permit delays then normal duration of 60-90 days you could be building at the worst weather in your area
• There are a lot of owner responsibilities but precious little builder responsibilities. They must have a requirement to build to applicable codes and standards.
• Indemnification is one-way, ask your attorney about this. Mine always advise me it should be two-way or none but never one-way in the contractor's favor for all small projects like this.

Please don't take this the wrong way. I think you're doing a great job asking questions and sadly too many prospective pool owners don't ask the questions then are shocked and maybe in financial hardship when the get too far down the road to stop. You're doing exactly the right thing. Ask many, many questions. Right now you have the ability to define the scope you want and what's affordable. This is right where you want to be. Keep up the great work on this. Start slow and finish fast is a great principle to use for successful pool building.

I hope this is helpful.

Chris

 

[mentalscastle]

@setsailsoon @Bill1974 @tgurske @JoyfulNoise @Buggs @Blackdirt Cowboy
Hey guys, really wanted to thank you from the bottom of my heart for all the amazing feedback above. Honestly didn't know a place like this exists and its beyond amazing and inspiring at the same time.

With that said I am in the process of getting some more bids and putting together somewhat of a document to shoot out to these companies with somewhat of a summarization of what is discussed above, what I discussed with some others outside TFP and my lawyer will most likely add in a few things and hopefully this weeds out some builders and puts me in the best possible situation. I plan on sharing the same images at the top of this thread as well.

If there are more to be added. Please chime in. I cannot thank you all enough. Yall all gems!!!!

 

[setsailsoon]

@setsailsoon @Bill1974 @tgurske @JoyfulNoise @Buggs @Blackdirt Cowboy
Hey guys, really wanted to thank you from the bottom of my heart for all the amazing feedback above. Honestly didn't know a place like this exists and its beyond amazing and inspiring at the same time.

With that said I am in the process of getting some more bids and putting together somewhat of a document to shoot out to these companies with somewhat of a summarization of what is discussed above, what I discussed with some others outside TFP and my lawyer will most likely add in a few things and hopefully this weeds out some builders and puts me in the best possible situation. I plan on sharing the same images at the top of this thread as well.

If there are more to be added. Please chime in. I cannot thank you all enough. Yall all gems!!!!

Mental,
Glad to help and great summary. I've tweaked a little and show this in red on attachment below. Don't be afraid to make this very clear. For example, use "will" or "shall" instead of "should". Also, listen to builder's comments. They will appreciate your willingness to let them comment/change your wording based on their experience. This also lets you develop a constructive relationship early. The best outcomes always are delivered with a cooperative relationship between you and the builder. Also when you think about a lump sum approach remember this transfers risk from you to them. If the risks are difficult to quantify, the builder needs to always price in more than they think they may incur to avoid taking a loss. Risks they are best at taking are items under their control such as labor, construction bulks, equipment, productivity. Risks they can't control like unknown underground conditions, weather etc are ideal candidates for a different approach like " included and expected cost plus adder/deduct for actual incurred".

I hope this is helpful.

Chris

 

[mentalscastle]

Thanks soo much @setsailsoon , also not sure if anyone ever heard of www.swimmingpoolsteve.com who is a consultant and based off the features of building he offers to be part of the process and go over all aspecs in terms of moving forward and all. Let me know your thoughts on this one. I am trying my best to do this the right possible way.

Another company came back to me and tried talking me out of gunite and suggested going with metal with a liner but after researching the company more thats their sweet spot so of course try to sell what you know. Anyway he did share some pics which are attached here that look amazing but at the same time I am unsure it will sit properly or be as heavy or sturdy as needed which I would also like some opinions here. The final image with the rocks on the side is prob the vibe id go for because since my ledge is soo steep I dont see any socializing down there, lol. Also what are the downsides of metal with liner?

Another thing thats crossing my mind is if the infinity edge thing might be a bad idea since its soo wide and the drop is soo much I think I am ok without it, but as long as the pool is still in this same area because taht view will still be beautiful no matter what. Also not sure if to maintain the catch will be a pain.

Once again I can't express my gratitude for the community here. I am involved in sneaker collecting and a lot of other things and all have communities but this one tops it all, which was soo surprising.

 

[JoyfulNoise]

So one of those pictures tells me I’d never want to work with the vinyl liner guy. There’s nothing wrong with vinyl and it might work better in your location than gunite/plaster but …

Notice the build picture that shows the skid loader and pipes. First - flex PVC is terrible and it’s used a lot where you are. Second, the plumbing work is sloppy - pipes laid over pipes crisscrossed and getting filled in with excavation dirt. That’s a big red flag. Finally, the shirtless dude squatting on the wall doing some kind of work on the pool wall … that’s a serious worksite safety violation. If that guy fell backwards and cracked his noggin on the edge of the pool wall below, there would a liability lawsuit out the waazoo … that’s sloppy site management.

But, you’d never know all that just by looking at the finished work product.

The more info you can get upfront, the better. Take your time, it’s important.