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Greg Jenkins
05-05-2010, 01:29 PM
Does anyone know how far an above ground pool should be from the house foundation and the below grade basement walls.
I am concerned about the load and the affect it could have on the basement foundation walls.
I don't see many pools and I can't find any info. on the subject.

John Dirks Jr
05-05-2010, 02:46 PM
The local code jurisdiction will usually address the distance from house requirement. Have you checked with your local AHJ?

Rick Hurst
05-05-2010, 04:47 PM
Having a best friend in the above pool business that carries a pool brand called Doughboy, I asked him and he said the only thing the manufacture recommends is the pool wall to be (6)ft. from the property line and (10ft.) from a street.
http://www.doughboy-pools.com/ServiceSupport/Images/documentsearch/AG02DOUGHBOYRND.pdf

As far as being constructed next to the house, there is nothing in the manufacture that states minimums. That pool wall is designed to hold and support that water *if* installed per the manufactures installation directions.

I've seen a number of these installed over the years and I have not seen too many AHJ even require a permit or inspection because they are not considered a permanent pool.

rick

Greg Jenkins
05-05-2010, 07:19 PM
I have not checked with the local ahj. I am not concerned about the pool structure. I am concerned about the load that the filled pool is placing on the below grade, rear foundation block wall. The weight of the water in the pool could exceed 50,000 lbs. (a wild guess). Some of that weight is located close to the rear foundation. See my point?

Raymond Wand
05-06-2010, 03:30 AM
Is the foundation poured concrete or block? Me thinks it may make a difference, but then again I would want to know how long the pool has been in this position, and if there are any signs of distress on this foundation wall.

H.G. Watson, Sr.
05-06-2010, 07:22 AM
Its proximity to electrical (AC and Service Lateral (or overhead) feeders, other services, and other - too close as pictured) is addressed in the Electrical Code (sections on pools, spas, fountains, etc.).

Proximity/obstruction for means of egress also addressed in Fire Code or Life Safety Code. Set-back to property lines usually addressed in Zoning - permitted uses. Set-backs to structures, others (pools, sheds, garages) also addressed in codes.

Body of water + electricity. This is the first issue of problem code-wise.

Your weight concern is negligable - A man standing on the dirt will exert more PSI or PSF on the soil than the water in that pool:

A U.S. liquid gallon of water is 3.785 liters weighs roughly 8.34 pounds. 42 inch depth would be for a sq. inch of area 42 cubic inches of water, which equals 0.181818 U.S. gallons or 0.181818 x 8.34 = 1.51656 pounds per square inch. A square foot of above ground pool footprint area that would be 42x12x12 cu. in. of water or 6048 cu. in. of water per sq. ft. of pool area, or 26.1818 U.S. gal. 26.1818 x 8.34 = 218.3562 pounds per square foot.

Another way to look at density and weight of water is to use approx 7.48 gallons per cubic foot of water.Area of a circle in square feet. Pi x radius squared (radius is half the diameter). So take a 16' perfect circle pool - radius = 8 feet. 8 squared is 64, 64 times Pi (we'll use rough 3.14) is about 201 square feet, lets multiply that by the height of the water (in this example 42 inches, or 3.5 feet) that would give us 201 x 3.5 = 703.5 cu. ft. of water. A cu. ft. of water is roughly 7.48 gallons. 703.5 cu. ft. x 7.48 = 5262.18 U.S. gallons x 8.34 pounds/gallon = roughly 43,887 lbs., but so what? That's still for an above ground pool, 42" water height, just 1.517 pounds per square inch, and 218.4 pounds per square foot with 3-1/2 feet of water.

I don't see a problem with the weight just the proximity as to electrical (and outlets), any controlls/pumps for the pool - unknown, emergency egress/exit path, encroachments to the required distance from the structure & its overhang (too close to house), Protecting the kids in the neighborhood from its dangerous/hazardous 'nuisance attraction' with a secure locked high-enough, and not easily climable, safety fence/gate as it is an "attractive nuisance" to other kids in the neighborhood, and potential flooding damage to the home should the pool fail.

It is too close to the egress windows, the overhang of the house, and the AC (equipotential grid for 36 in. near a/c disconnect; all directions beyond required path within 'zone' of pool) and electric disconnect & required outside receptacles. GFCI for all recps in 'zone' required ground bond.
Provisions to prevent syphoning/backflow (vac breaker, etc.) to the hose bib in place (contaminate water supply). The AC is under the low overhang from the roof, etc. Exterior lighting, receptacles, and AC electrical too close to pool. What provisions have been made to protect adjoining properties from inadvertant pool drainage/failure (lined swale, etc.) drainage or diversion from the rear lot pitch (pool location proximity to rise in slope leads me to believe this may not exist or has been compromised by placement of pool). The required slope away from the foundation likely has also been compromised to flatten the area for a level pool on the soil/rocks/pad (6-10 feet out) These are the more important issues.

Weight impact of the water in the above-ground pool itself upon the soil and thereby the nearby foundation is negligable. However, if you are in an area with soil that should be regularly and evenly wetted to avoid foundation damage - it (the pool covering the soil) would negatively impact. Near total yard coverage ratios (for absorbing versus redirecting rainfall, etc.) may also be of issue (zoning/codes, density, storm water, etc.). What I do see is an indication of a sloped lot pitched towards the pool, home, foundation & AC (first picture right foreground follow fence line to right goes uphill), which leads me to think hydrostatic pressure to soil and surface water runnoff & accumulation against foundation is likely, long shot from home behind you towards that area of higher elevation beyond the pool might further confirm that concern of a snow-melt, rain, or pool wall/liner failure to flooding the AC area and low foundation.

See also Article 680 NEC Parts I and III, see esp. Definitions in Part I for 'Pool' and 'Storable Swimming, Wading, or Immersion Pool' 10' zone outwards (horizontal) from walls upwards for overhead, 5' zone outwards from walls for underground, 6' zone for receptacles. Bonding and Grounding Requirements (GFCI receptacles must have ground in 'the zone'. Under eave protected receptacles, etc. that may have been formerly 'damp location' may have become 'wet location' in 'the zone' of the side walls of the errected semi-permanent or storable pool.

Greg Jenkins
05-06-2010, 10:58 AM
Wow - More info. than I bargained for. Lots of good stuff to contemplate.
Thanks for you insight.
Greg

Randy Mayo
09-07-2010, 05:54 PM
Greg

Without doing the engineering calculations you would be OK if the pool is as far away as the foundation is deep. For example if the foundation footing is 6-foot deep keep the edge of the pool 6-feet away.

Jess Moznot
12-06-2010, 11:33 AM
Having a best friend in the above pool business that carries a pool brand called Doughboy, I asked him and he said the only thing the manufacture recommends is the pool wall to be (6)ft. from the property line and (10ft.) from a street.
rick

I think this would be correct so far as the foundation is not more than 6 ft. deep. Also, keep in mind where you are going to run your spa filters (http://www.familyleisure.com/Pool-Spa-Filter-Cartridges/) as this will also greatly effect the placement of your pool. Cheers!

Marc M
12-30-2010, 07:20 PM
The local code jurisdiction will usually address the distance from house requirement. Have you checked with your local AHJ?

JD's correct...

Phil Brody
12-31-2010, 12:51 PM
As an engineer, what you perceive might be existing and what is are two different things. The lateral loading on the foundation will be virtually nonexsistent since the load will be rapidly dispersed throughout the surrounding soil. Remember the load will go straight down, so any load on the foundation would have to come from soil compression.

Door Guy
01-01-2011, 10:28 AM
As an engineer, what you perceive might be existing and what is are two different things. The lateral loading on the foundation will be virtually nonexsistent since the load will be rapidly dispersed throughout the surrounding soil. Remember the load will go straight down, so any load on the foundation would have to come from soil compression.

Totally agree... and it's not likely the soil will be compressed unless it was fill.

H.G. Watson, Sr.
01-01-2011, 11:36 AM
old threads being revived!

Which was already pointed out isn't much more than an average guy walking around on the soil.

However both LI and Mich overlook the discussion elements regarding the topography of the region, ledge, expansive soils and the presence of the large area soil covering's possible effect on same, and/or drainage, in regions prone to such issues.

I really think the subject was already pretty fully explored and exhausted long ago, specific to the OP's questions and photos.

Phil Brody
01-01-2011, 06:01 PM
True this was an old thread and I'm not sure how it came to light, but it really didn't seem the question was fully answered. The one thing I don't understand about these boards is a poster will ask a question which may or may not be answered but many will chime in to many tangential or colateral issues as if to show how thorough they can be. I totally apreciate their throughness but think it would be more constructive to limit the response to the question at hand unless the poster queries "any additional items that might be in question".

H.G. Watson, Sr.
01-02-2011, 08:02 AM
True this was an old thread and I'm not sure how it came to light, but it really didn't seem the question was fully answered. The one thing I don't understand about these boards is a poster will ask a question which may or may not be answered but many will chime in to many tangential or colateral issues as if to show how thorough they can be. I totally apreciate their throughness but think it would be more constructive to limit the response to the question at hand unless the poster queries "any additional items that might be in question".



Interesting. Seems you missed the actual original overall question, the poster's location, the provided photos, and the summarization/conclusion.




Does anyone know how far an above ground pool should be from the house foundation and the below grade basement walls.
I am concerned about the load and the affect it could have on the basement foundation walls.
I don't see many pools and I can't find any info. on the subject.

H.G. Watson, Sr.
01-02-2011, 08:39 AM
As an engineer, what you perceive might be existing and what is are two different things. The lateral loading on the foundation will be virtually nonexsistent since the load will be rapidly dispersed throughout the surrounding soil. Remember the load will go straight down, so any load on the foundation would have to come from soil compression.

Explain yourself!

http://www.inspectionnews.net/home_inspection/attachments/pool-spa-home-inspection-commercial-inspection/17655d1273091305-above-ground-pool-close-house-foundation-dscn2993.jpg


http://www.inspectionnews.net/home_inspection/attachments/pool-spa-home-inspection-commercial-inspection/17656d1273091305-above-ground-pool-close-house-foundation-dscn3005.jpg

Rod Butler
01-05-2011, 11:34 AM
Explain yourself!




If I understand him he is in complete agreement with your May 6th post.

Heron Longoria Jr.
01-13-2011, 10:41 AM
Don't know if anybody's mention the "water bonding" now required by the 2008 N.E.C...Section 680.26(C)....intentional bond of the water from the rest of the bonded system of he pool...
This is something everyone needs to start looking at and probably no one is at all...

Rick Hurst
01-13-2011, 01:14 PM
Don't know if anybody's mention the "water bonding" now required by the 2008 N.E.C...Section 680.26(C)....intentional bond of the water from the rest of the bonded system of he pool...
This is something everyone needs to start looking at and probably no one is at all...

Mr. Longoria,

As a pool inspector, please don't assume we all fell off the turnip truck this morning.:D

rick

mikevador
07-09-2022, 07:18 AM
http://www.inspectionnews.net/home_inspection/attachment.php?attachmentid=35157&stc=1 Hello,

I have the similar question, so i'm from EU, i try to translate my dimenssions to US values

So i want to place a litle pool near to my house.
I have very small garden.
I have a garden zone of 16x10M agains the house.
So i can put the pool near to 3 feet of house

The pool 2x4x1 meters => 6,5x13,2 water lever 3,3 feets.

My house have a -1 level to groud (cellar) and the garden is on 0 level.

I'm affraid about the wieght of pool 18000 lbs.

So i'm worried about cellar wall to have some horizontal pressure maked by the pool
So H.G. Watson said that not be a big problem.

Can you confirm, i tried to contact engeneering company to have an advice but my project is to small to have any return of information.

Best regards.

Jerry Peck
07-09-2022, 05:08 PM
Typical code and engineering will state to figure a 45?angle down and outward for load bearing forces.

Nature likes an equilibrium and that 45? angle typically provides for that.

From the pool edge at the bottom, go down and out 45? for the weight of the pool and water in it, do the same from the top of the pool for the horizontal load on the pool walls.

A 1.5 meter deep pool, go horizontal 1.5 meters and down 1.5 meters, that angle (45?l from the bottom of the pool is where the load (weight) of the pool goes.

If the basement floor is 2 meters below ground level, the load of the pool will be against the lower part of the basement wall if the pool is placed only 1.5 meters from the basement walls, and the horizontal load of the pool walls will also be against the basement wall from 1.5 meters down and lower.

Put the pool at least as far from the basement wall as is the depth of the basement wall is below ground level (2 meters in my ecample) to avoid issues.

If that is not possible, then the pool wall can be designed with reinforcement as needed to transfer the loads to the pool bottom (i.e., essentially an 'above ground pool wall' for an inground pool).

The engineer can design the pool wall to whatever is required for the distance the pool will be from the basement wall - the farther from the basement walls, the less reinforcement needed.

There will ... should .. ALWAYS be reinforcement in the pool walls, which will allow the pool to encroach on that 45? angle from the basement walls ... only your engineer will be able to tell you how close to the basement wall a pool can be for what depth pool it will be.

The bearing capacity of your soil also effects your pool location: soil rock - basically quite close; soft soil with limited load bearing - stay way outside that 45? angle.

I realize we're basically back where you started your question, but hopefully with some additional knowledge of things which need to be considered in the answer to your question.

Jerry Peck
07-09-2022, 06:34 PM
[So i want to place a litle pool near to my house.
I have very small garden.
I have a garden zone of 16x10M agains the house.
So i can put the pool near to 3 feet of house

The pool 2x4x1 meters => 6,5x13,2 water lever 3,3 feets.


I got mixed up on the above dimensions of "16x10M" and "2x4x1 meters => 6,5x13,2", thinking 6.5x13.2 meters and didn't know what the 16x10M meters was, so I went 'worst case scenario'.

I'm now thinking 16x10M is backyard? Or about 52'x33'?

With the garden pool being about 6'6"x13'3" and 3'4" deep.

I got the "near to 3 feet of house" part but it 'did not compute' at the time with the other thing - me bad.

If the pool is 6'x13' (rounded off) X 3' deep, that's 234 cu ft x 1,755 gallons x 8.3 lbs/gal = about 15,000 lbs, so we're close on that.

6'x13' = 78 Sq ft ... 15,000 ? 78 = 192 lbs Sq ft load on the ground.

Over here on this side of the pond, soil typically needs to have a minimum bearing capacity of 2,500 lbs sf ft, so you are well within that (making all kinds of presumptions here).

3' from the house, 3' deep, 45? angle, begins to put some load on the basement walls at 6' below ground if I'm doing the math correctly.

Bottom of pool is 3 feet deep, 45? angle from there at 3 feet out (to basement wall) is 6 feet down for pool weight; 3 feet to 6 feet down on basement wall for horizontal load on pool wall.

How much does 234 cu of your soil weigh? A Google search came up with 74-110 lbs cu ft, and about 78 lbs cu ft for loose soil (from here: https://dreamcivil.com/how-much-does-dirt-weight/#:~:text=A%20cubic%20foot%20of%20dirt,78%20lbs%20p er%20cubic%20foot ). Considering what is to be dug out is undisturbed soil (somewhat compacted by nature), let's use 100 lbs cu ft for the soil being replaced by the pool ... 234 x 100 = 23,400.

Being that concrete typically weighs 150 lbs cu ft one could calculate the approximate weight of the concrete (L X W X D of pool for pool water volume and L X W X D of pool adding 3" thick bottom and sides for total pool volume, the deduct water volume from total volume to estimate concrete volume).

If water volume is (from above) "6'x13' (rounded off) X 3' deep", total volume might be 6.5 x 13.5 x 3.3 = 290 cu ft - 234 cu ft water volume = 56 cu ft concrete volume x 150 = 8,400 lbs (guesstimated)guesstimate.

15,000 lbs water + 8,400 lbs concrete = 23,400

Which just happened to be the same weight as the soil being removed.

Honest, I didn't do the math and reverse engineer it to come out the same! I just typed and did the math as I worked through it.

Anyone want to check my math to see if we magically replaced the soil with heavier concrete and lighter water in the right volumes to offset the soil weight?

mikevador
07-09-2022, 11:55 PM
Hello Jerry Peck,

Thanks so much for your fast response to my question.

Sorry for the dimensions,

The pool dimensions is : 6,5 x 13,2 feets, and the deep (but deep outside the ground i mean the height of the pool) is 3,3 feets.
So the estimated weight is 17800 pound / lb.

My ground arround house have been moved 5 year ago, so now the ground have take time to be 'compressed/stabilise'.

I looking and see that the weight of ground is approx 2 time more heavy of water (for in groud pool case), so if remove ground aprox 3,3feet/2 , i can compense, but the pool is not inside ground is above ground pool (tubular / frame pool) placed on the floor.

Best regards.
http://www.inspectionnews.net/home_inspection/attachment.php?attachmentid=35158&stc=1

mikevador
07-10-2022, 12:32 AM
Typical code and engineering will state to figure a 45?angle down and outward for load bearing forces.

Nature likes an equilibrium and that 45? angle typically provides for that.

From the pool edge at the bottom, go down and out 45? for the weight of the pool and water in it, do the same from the top of the pool for the horizontal load on the pool walls.

A 1.5 meter deep pool, go horizontal 1.5 meters and down 1.5 meters, that angle (45?l from the bottom of the pool is where the load (weight) of the pool goes.

If the basement floor is 2 meters below ground level, the load of the pool will be against the lower part of the basement wall if the pool is placed only 1.5 meters from the basement walls, and the horizontal load of the pool walls will also be against the basement wall from 1.5 meters down and lower.

Put the pool at least as far from the basement wall as is the depth of the basement wall is below ground level (2 meters in my ecample) to avoid issues.

If that is not possible, then the pool wall can be designed with reinforcement as needed to transfer the loads to the pool bottom (i.e., essentially an 'above ground pool wall' for an inground pool).

The engineer can design the pool wall to whatever is required for the distance the pool will be from the basement wall - the farther from the basement walls, the less reinforcement needed.

There will ... should .. ALWAYS be reinforcement in the pool walls, which will allow the pool to encroach on that 45? angle from the basement walls ... only your engineer will be able to tell you how close to the basement wall a pool can be for what depth pool it will be.

The bearing capacity of your soil also effects your pool location: soil rock - basically quite close; soft soil with limited load bearing - stay way outside that 45? angle.

I realize we're basically back where you started your question, but hopefully with some additional knowledge of things which need to be considered in the answer to your question.


Perfect, i understand what you want to mean and confirm that i thinking,

In your example, i need minimum 1 meter pool height+ 2 meter height of fundations so need minimum 3 meter of distance of house fundation.

And more complex in my case the garden ground is sloping in house direction so i have already some more others loads to the fundations.

So the project is not possible for me bescause garden is too little and if install pool on the minimal 3meters of my house wall, i will be in the neighbour garden or forbidden building zone (cause de law here: must need 3 meter beween pool and neighbour garden).
So also wanted only a out ground pool for cost reasons (builded pool costs 30x of above ground frame pool here) 2000$ against 60.000$ builded.

I have annother litlle zone but here the border of the pool will be at 1 meter of edge land slope, so maybe generate a landslide.

The height of slope measures also 3 meters , so if a take the same calculs , the border of pool must be at 3 +1(height of above groud pool) so 4 meters minimal of edge of the slope (same if the sloop have an angular height not same that vertical ground wall) but take more security conditions.
The engeneering tests (house builder) of my ground said that my ground/soil is compressible and movable, so don't want to generate a landslide.

Thanks so much.

Jerry Peck
07-10-2022, 05:36 AM
... but the pool is not inside ground is above ground pool (tubular / frame pool) placed on the floor.

Ah, got it now.

It is an above ground pool. Which means everything is being added.

I haven't looked at above ground pool installation instructions in a number of years, but my recollection is that the manufacturer's installation instructions addressed the pool location, and where not to put the pool, in addition to how to assemble the pool, the wiring, etc.