Radiant Pool semi-inground...concrete blocks for the collar?

[IAHawkeye02]

Hi! Long time reader, first time poster....

Background:
- We purchased a Radiant, rectangle pool 16' x 32', it has shipped and we are expecting it next week (fingers crossed). We opted for no deep end (52" max height) and plan to bury the pool somewhere between 24" - 30" (we are still discussing depth).
- This project will be all DIY (as all the local pool installers were booked for most of the summer). We have the equipment to do the job, experience with outdoor projects and have owned an in-ground pool before, just not built one.

Issue - Concrete Collar:
- Our pool requires a 8" concrete collar around the perimeter of the pool along with concrete footers. Because we have a newer 330' concrete driveway that is only 4" or 5" in most spots a concrete truck cannot drive on it or get near the pool build site or we risk the truck will crack our driveway.
- We looked into hiring a pumper truck, but because of how our property sits, the pumper truck company said they could *probably* do it, but they would have to charge us a "ton of money" to do it (their words). Also using a concrete hopper or two is out, because round trip from the concrete truck parked on the street to build site is close to 15 minutes and risk things tipping over because of rough terrain in certain spots on the way to the pool build site.

Options:
(FYI, I couldn't find any threads regarding this topic)
1. Use 2 electric concrete mixers (one rented, one my dad owns) near the pool site and mix and pour the concrete ourselves (with the help of friends/family and likely some paid college kids lifting the concrete bags into the mixers). It will likely take around 500 bags of concrete for this project, with most being used for the collar.
2. Use 1 row of concrete blocks, stacked and leveled on rock, around the entire pool perimeter and fill them with concrete. This was recommended by my dad. This approach reduces our overall costs and tedious effort of mixing and pouring such a huge amount of concrete. Since our pool is a rectangle, it seems like this should work fine.

Does anyone have any advice or concerns re: using concrete block (not cinder block) filled with concrete for our pool collar? Keep in mind this is only 1 row of blocks as the collar only has to be 8". We plan to follow the directions/guidance on back-fill around the pool, leveling, etc. This question is just about the collar.

Any help is appreciated!

 

[RETIREDGENCON]

Hi! Long time reader, first time poster....

Background:
- We purchased a Radiant, rectangle pool 16' x 32', it has shipped and we are expecting it next week (fingers crossed). We opted for no deep end (52" max height) and plan to bury the pool somewhere between 24" - 30" (we are still discussing depth).
- This project will be all DIY (as all the local pool installers were booked for most of the summer). We have the equipment to do the job, experience with outdoor projects and have owned an in-ground pool before, just not built one.

Issue - Concrete Collar:
- Our pool requires a 8" concrete collar around the perimeter of the pool along with concrete footers. Because we have a newer 330' concrete driveway that is only 4" or 5" in most spots a concrete truck cannot drive on it or get near the pool build site or we risk the truck will crack our driveway.
- We looked into hiring a pumper truck, but because of how our property sits, the pumper truck company said they could *probably* do it, but they would have to charge us a "ton of money" to do it (their words). Also using a concrete hopper or two is out, because round trip from the concrete truck parked on the street to build site is close to 15 minutes and risk things tipping over because of rough terrain in certain spots on the way to the pool build site.

Options:
(FYI, I couldn't find any threads regarding this topic)
1. Use 2 electric concrete mixers (one rented, one my dad owns) near the pool site and mix and pour the concrete ourselves (with the help of friends/family and likely some paid college kids lifting the concrete bags into the mixers). It will likely take around 500 bags of concrete for this project, with most being used for the collar.
2. Use 1 row of concrete blocks, stacked and leveled on rock, around the entire pool perimeter and fill them with concrete. This was recommended by my dad. This approach reduces our overall costs and tedious effort of mixing and pouring such a huge amount of concrete. Since our pool is a rectangle, it seems like this should work fine.

Does anyone have any advice or concerns re: using concrete block (not cinder block) filled with concrete for our pool collar? Keep in mind this is only 1 row of blocks as the collar only has to be 8". We plan to follow the directions/guidance on back-fill around the pool, leveling, etc. This question is just about the collar.

Any help is appreciated!

Response:

If I understand your description of constructing the cap itself, filled concrete block sitting atop a rock base is not only a concern, but likely a source of a potential real problem. Backfill will be entirely insufficient to hold in place what you are describing. I went to the Radiant site to examine the installation instructions. The cap as shown is monolithic, or poured integral with, the concrete footing and is illustrated to cover a portion of the pool side construction up to the weld point of the A-frame struts surrounding the exterior. This is most certainly to compensate for the force of structural deflection being imposed upon that point by the considerable water weight against it. So with respect to your alternate proposal, it's not possible anyway because the cap needs to be monolithic with the spread footing in order to be structurally sound. The consequence otherwise will likely result in an ultimate blowout at a point or points between the A-frame struts or even at a strut itself. As I mentioned, the required backfill will not prevent movement of a cell-filled cap arrangement.

Also, while a boom pump would undoubtedly be entirely cost-prohibitive for such a project, a towable 3" hose capacity concrete pump utilizing pump mix is ideal for this kind of project and might even be rentable in your state. Otherwise, freelancers are available with such a pump and are indeed reasonable in cost. The pump can be staged at the road to be filled by the trucks as necessary and can easily pump up to 1000 yards in distance or more to a reasonably equal in level project. Using bagged products for this would be a last resort in my opinion and concrete integrity can be challenged by the need to use a reasonably consistent mix over the span of such a large quantity of bagged concrete. The overall point here is that if you've spent a considerable amount on your pool, don't try to escape a reasonable cost and adherence to the manufacturer's instructions for establishing a suitable foundation. As a retired contractor, I've certainly observed my share of workarounds that most always result in the need for correction.

One last word regarding your pool liner. I've seen numerous issues with even the thickest of these vinyl liners regarding penetration by ants seeking water. To my initial astonishment, I have been shown the evidence of where these ants make their way to the underside of the liner and simply chew their way through until they reach the pool water, naturally ruining the liner. If your manufacturer provides any recommendations for preparations to inhibit ants from reaching the liner to damage it, I'd follow any recommendations rigidly. I've seen or heard of such instances many times, so just a word of caution in that regard.

 

[IAHawkeye02]

Thanks so much for your response. You definitely bring up some valid points for sure.

I want to be clear, we weren't going to use just concrete block to support the pool structure, we planned to do the full concrete footings, etc. but were considering using concrete blocks that look like cinderblocks (so they have openings in them) but are made from actual concrete and not a byproduct and then filled and surrounded with wet concrete and also positioning rebar as well, etc.to further support the collar requirements. We tried to get the full install instructions from Radiant (we found some from Canada, but we don't know if they are the most current version, etc.), but they will not send them to us in advance of pool delivery/directly and instead are requiring us to get them from our pool dealer (which is fine, I just requested they send them to him via email so we don't lose a weekend of building time as the is scheduled to be delivered this week still...our pool dealer is new to selling Radiant Pools, he's sold lots of other kinds of pools the past 30+ years, just new to Radiant so he can't tell us right off hand the installation recommendations). Anyway, I will update the post (or start a new one) with pictures and info re: final install decision.

Also it was interesting you brought up ants chewing through the liner, I read some posts about that a few years ago when we first started doing some initial research about putting in a pool and had been researching it in greater detail this past week as I was trying to figure out what we could do for soil prep and/or during install. One site recommended CYPERMETHRIN for ground prep for termites, but I need to do some more research for ants. I noticed a lot of the Radiant pool builders who post videos often use vermiculite for the pool base and wondered if that might help keep ants away, even though that is not what the manufacture seems to recommend for the pool base from what we could find so far. If the install instructions don't mention anything about it, I will definitely reach out to Radiant. We have 2 neighbors that also have vinyl lined pools and have for some time and when we spoke to them they did not mention any concerns re: ants causing holes, but we still want to be prepared for worst case scenarios.

 

[jscherrer18]

Thanks so much for your response. You definitely bring up some valid points for sure.

I want to be clear, we weren't going to use just concrete block to support the pool structure, we planned to do the full concrete footings, etc. but were considering using concrete blocks that look like cinderblocks (so they have openings in them) but are made from actual concrete and not a byproduct and then filled and surrounded with wet concrete and also positioning rebar as well, etc.to further support the collar requirements. We tried to get the full install instructions from Radiant (we found some from Canada, but we don't know if they are the most current version, etc.), but they will not send them to us in advance of pool delivery/directly and instead are requiring us to get them from our pool dealer (which is fine, I just requested they send them to him via email so we don't lose a weekend of building time as the is scheduled to be delivered this week still...our pool dealer is new to selling Radiant Pools, he's sold lots of other kinds of pools the past 30+ years, just new to Radiant so he can't tell us right off hand the installation recommendations). Anyway, I will update the post (or start a new one) with pictures and info re: final install decision.

Also it was interesting you brought up ants chewing through the liner, I read some posts about that a few years ago when we first started doing some initial research about putting in a pool and had been researching it in greater detail this past week as I was trying to figure out what we could do for soil prep and/or during install. One site recommended CYPERMETHRIN for ground prep for termites, but I need to do some more research for ants. I noticed a lot of the Radiant pool builders who post videos often use vermiculite for the pool base and wondered if that might help keep ants away, even though that is not what the manufacture seems to recommend for the pool base from what we could find so far. If the install instructions don't mention anything about it, I will definitely reach out to Radiant. We have 2 neighbors that also have vinyl lined pools and have for some time and when we spoke to them they did not mention any concerns re: ants causing holes, but we still want to be prepared for worst case scenarios.

I'm strongly considering a Radiant Pool and wondering what you ended up finding out about ants. I haven't come across this as a problem when researching pools here in Wisconsin.

 

[IAHawkeye02]

I haven't found much online (and did a lot of research). The instruction manual encourages you to treat the area for termites and ants around the forms, base and surrounding area before you install the liner, but to allow for time to dry before installing the liner. We are going to have our exterminator come out before we install the liner, but don't want it to wash away with a summer rain before we are at that part of the project (we are covering our work area with a heavy duty 30 x 50 tarp from Menards along with ground pins and additional weight such as 2 x 4s during stretches of rain to prevent undoing our progress). A few of the install videos I looked at used a special insecticide over their vermiculite base to prevent pests, but both have to be hand troweled and both are out of scope for our project -- as every pool builder is swamped this year, so it's all DIY for us, but if this is something you are going to have installed next year and are not doing it yourself, definitely something to look into. We are taking tons of pictures and taking notes of our project. Expect a post from us in the next few weeks outlining our project build.

 

[phonedave]

I will cast an other vote for looking into a concrete pump. It is going to be tough to make a monolithic pour with just two small mixers (they are electric, so they must be what, 2 maybe 3 sacks max) 500 bags is a lot of stress on both the body, and the mixer itself. I have a one sack electric mixer and have done a number of pours of 5 - 6 sacks, and I don't think I would go to anything larger - it gets old quickly (granted I am working by myself, but still, it's not fun working such small batches)

When you say concrete hopper are you referring to a power buggy?

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.

They handle some pretty rough terrain, hold a lot, and move pretty quickly. For it to take 15 minutes one way in one of those would give you a huge piece of property. How far and what sort of terrain are we talking about?

 

[IAHawkeye02]

Hi phonedave,
Yeah, the hopper I was referring to was a concrete buggy (my vernacular when it comes to building equipment and materials is not always on point, ha).

So my husband has a little experience with the concrete truck process as he worked for a company that owned several concrete facilities about 15 years ago. The problem with using the buggy is it takes so long to transport the concrete from the street to the pool site that most concrete trucks can't or won't sit the length of time for us to clear out a load (or even partial load) of concrete otherwise we would have gone that route (somewhere around 500+ feet from the concrete truck to pool area). So we estimated around 15 minutes round trip from load up, dump and back plus having to go over an area that is not perfectly sloped. We live on 3 acres, we live near the top of a bluff (but not on the peak), so when we had it graded when we built, it was done in a way that the water flows down the driveway and away from the house on the sides, so the sides of the house would be tricky in a buggy as we have some major ruts/run off spots on the side we use to access the backyard (the other side is a sloped ravine with trees and brush). We for sure would have used a buggy/buggies if we thought we could make it work.

We started concrete tonight, first corner trench support/footer took approximately 25, 60lbs bags of concrete/quikcrete mix. It was super fun (jk, it was terrible). But we figure it is what it is. Originally, it was implied in the directions we found online (and the 30+ YouTube Radiant install videos) that we wouldn't need to dig footers for this pool because it would be 30" underground. Since the directions weren't clear after we got them, we called Radiant and talked to someone there (who wouldn't "officially give us advice"), but said if it was him, he would dig footers (in addition to the collar) under the metal support brackets. He basically said don't skimp on the concrete and that concrete is our friend. So...we are becoming one with the concrete. All 500+ bags of it...I should also note, we only used the concrete blocks in very specific locations based on the recommendation from the Radiant person (and the directions), which was for any sections that were less than 24" below grade he recommended a long trench footer with blocks used for support between the l/a frame brackets. So that's what we are doing in one corner. The rest will be just footers under the metal brackets (as the rest are more than 24" below ground). We also get to pour a 8" x 12" collar around the entire perimeter of the pool. We are using rebar to tie everything together, etc. We are also considering hiring some strong college guys to help us open and pour the concrete bags into the mixer(s). Good times, ha!

 

[rcerf]

In the video , watch how they open the bags of concrete to put in the mixer. It works great and makes it much easier to handle. I’ve mixed three pallets of 80 pound bags at it makes it much more manageable.

 

[IAHawkeye02]

Rcerf - That's an awesome video! Thanks for sharing!