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I'm considering getting an ~300 gallon (~1100 litre) intermediate bulk container (IBC) tote to use as a rain barrel, which at 8 lbs per gallon (1 kg per litre; 2500 lbs / 1100 kg total) can get quite heavy when full. I would need to store this near my foundation in order to collect water from my downspouts -- Is there any precautions I could/should take to avoid foundation damage? I suspect I'll need to contact a foundation company/engineer to get the "real" answer, but before I start with that I figured I'd start with the internet first.

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    Of course one important aspect of your question you haven't shared is the type, depth, and age of your foundation.
    – isherwood
    Commented Jun 19 at 20:32
  • I'd recommend keeping it a few feet away if possible for access. Commented Jun 19 at 20:45
  • This might not apply to your situation but if you have an older clay drainage system that wraps around the foundation, diverting water from it may cause the ground to subside near the foundation which could cause this barrel to tilt. I have a patio that sank about a quarter of an inch after diverting downspouts away from the old clay system.
    – JimmyJames
    Commented Jun 20 at 20:32

2 Answers 2

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There are specifications for load-bearing pressures of foundation materials.

International Building Code gives values between 1500 to 12000 lbs/ft² (7300 to 59000 kg/m²). Lowest for clay or sand, highest for bedrock.

A 3 feet (9 dm) high water tank is 190 lbs/ft² (930 kg/m²), so you are well below even the lowest limits.


The above values address the situation where the soil would start to shift due to the load, which wouldn't immediately affect the foundation but would be a long-term issue with e.g. drainage and any underground pipes.

In the comments a concern was raised that if the foundation wall was exceptionally weak, the horizontal forces from increased ground pressure could still affect it. Basically meaning that the wall would be weaker than the soil.

We can further compare this to the live loads table which gives design surface pressure of 100 lbs/ft² for "Yards and terraces, pedestrian" and 250 lbs/ft² for "Sidewalks, vehicular driveways and yards, subject to trucking". No margin here, though these are the minimum design limits which would typically be exceeded by a lot if there is no hollow structure underneath the yard.

I agree that the topic is more complex than what my initial answer presented. To properly calculate lateral earth pressure due to the surcharge load would require quite detailed analysis.

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    These values show how much the ground can support - it indicates that the soil itself is not going to give way underneath the load, but it says nothing about how strong the construction actually is. I'm not sure these values say anything at all about whether the load would exert enough horizontal pressure to affect the foundation. A retaining wall can get pushed over from the lateral pressure of the dirt alone even without any load at all - the fact that the soil could withstand 1500 lb/sqft doesn't imply that the wall stays up as long as you don't put >1500 lb/sqft on top of it. Commented Jun 20 at 17:58
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    There's no element addressing the foundation construction here - this answer would seem to suggest that if you put up to 1500lb/sqft on clay soil near a foundation, it doesn't matter at all whether your foundation is made of cinder blocks or toothpicks or cellophane, it won't fall over. I'm not sure the values given here are relevant, it suggests that what a foundation can withstand depends only on what kind of soil it's in, and not at all how it's built. Commented Jun 20 at 18:00
  • @NuclearHoagie wouldn't a foundation be stronger than soil? (If not why build it) Commented Jun 20 at 22:16
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    @NuclearHoagie I agree that it would be possible to build a basement with such weak walls that the ground would become weaker than it was before the building was put into place. But to do so by 7x margin sounds rather unlikely, and I think commonly the concrete/masonry foundation is easily much stronger than any clay.
    – jpa
    Commented Jun 21 at 5:44
  • As jpa's followup indicates, this is a complicated thing. To talk of relative strength in a casual venue like this is a bit silly. The factors and variables involved are plentiful. For what it's worth, I've seen a few block foundations show movement, but only after overzealous water compaction and before the weight of the home was entirely in place. Displacement of modern foundations later is extremely rare, barring seismic activity or natural disaster.
    – isherwood
    Commented Jun 21 at 12:46
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No. People park work trucks and hot tubs against their houses all the time. Unless you have a preexisting foundation problem, extreme rain events, a severe slope, or other obvious risk factors, don't worry about it.

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  • An above-ground oil tank is another good example of a similar size/weight object commonly found near a foundation, and additionally would typically have some type of inspection or installation approval from the municipality. Commented Jun 26 at 18:08

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