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I haven't seen any tables above 70PSF. Based on my calculations, a rain barrel full of water exerts about 168PSF. I live in the mountains in Colorado so I can probably expect additional weight in snow. Adding a 20% safety factor, puts me at a static load of 1.40PSI.

PI * (22.875" / 2)^2 / 144 = 2.85 SF 
(55gal * 8.34lb/gal + 21.5lb) / 2.85 = 168.49PSF
168.49 * 1.2 / 144 = 1.40PSI

I realize that the qualitative details of this question might be better answered in an off-grid forum, but I need the table data, which I though someone knowledgeable of a reference would be easier to find in the forum.

mreff555
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  • Pardon for asking, if you have 200 pounds weight spread over 2.85 SQF (the size of barrel), then the load is 70 PSF – asinine Sep 13 '23 at 06:26
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    I believe The Sagulator has a framing mode... FWIW, my platform is 2x6 framing on notched 4x4 uprights on concrete footings, diagonally braced at all corners, 2x6 decking, plenty of decking screws. I don't remember whether I used metal reinforcement for the joints; I don't think so. This is probably overbuilt, if anything; seems perfectly content to carry two 80G barrels static load plus 209 pound live load (me) – keshlam Sep 13 '23 at 08:16
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    Unless you like bursting barrels, snow load should only apply when the barrel is empty, so it's a non-factor (or only temporarily a factor until the barrel bursts, the liquid water remaining drains out, and then the next thaw takes care of the ice that didn't drain.) Correct value for PSI is 1.11 (you apparently multiplied 161 PSF by 144 instead of dividing by 144) – Ecnerwal Sep 13 '23 at 12:01
  • You could always build with steel. Also, I'm not sure what the question is here. – FreeMan Sep 13 '23 at 13:47
  • I'm assuming the 55 in the OP's calcs is gallons—which is 460 lb, not including the weight of the barrel. – Huesmann Sep 13 '23 at 13:47
  • @keshlam, I added units for clarity. I never said 200 lbs. I said 200PSF (pounds per square foot). – mreff555 Sep 13 '23 at 14:23
  • @FreeMan, you'd only have to read the first sentence to answer your confusion. I'm not a steel fabricator. I'd prefer build this from items I can get at the hardware store. – mreff555 Sep 13 '23 at 14:23
  • @Ecnerwal, I don't entirely follow your logic. If I have a closed barrel, regardless of its contents, snow is going to collect on top of it. If it isn't a factor, 200psf is probably still reasonable b/c of the barrel weight as Huesmann pointed out. Otherwise I may need to increase the safety factor. – mreff555 Sep 13 '23 at 14:29
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    Just because you _prefer_ to nail together some wood doesn't mean you can't bolt together some angle iron from a different aisle at the same hardware store. I can't weld either (though I want to learn), but I'd seriously consider some steel for this project. Also, your first sentence doesn't state that you _don't want_ metal or _cannot assemble_ anything from metal... We often do frame challenges here - you're up to your eyeballs in the project and sometimes can't see other options... Happens all the time (to me, even...) – FreeMan Sep 13 '23 at 14:37
  • Have you considered the weight of the water, it is over 8.3 pounds per gallon. I am assuming it is over the 50 gallon size. – Gil Sep 13 '23 at 15:10
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    I believe Ecnerwal's point is that if it's the season for snow, then you're not likely to have (and probably should not have) any water in the barrel (since it may freeze and burst the barrel). So calculating for both a full barrel and having snow on top at the same time is overkill. – brhans Sep 13 '23 at 16:44
  • The weight of the water that shouldn't be in the barrel in freezing weather is much greater than the weight of the snow that can build up on the barrel. – Ecnerwal Sep 13 '23 at 23:43
  • @keshlam, yes I did the same math above, except 55 gal plastic closed lid barrels are 22 7/8 diameter. This is a valid static load calculation. – mreff555 Sep 15 '23 at 17:03
  • I see you've corrected the original number, which was off by many orders of magnitude. Thanks. (Typing error?) So you're getting a static load (for a single barrel a bit less than mine. It sounds like a big number, but wood is strong stuff if you use something of adequate size. – keshlam Sep 15 '23 at 17:35
  • I see barely any deflection in my 5/4 (full 1") deck boards, even when my heavier barrel is full. The frame likewise seems rock solid. My conclusion is that I probably overbuilt by a substantial amount.) – keshlam Sep 15 '23 at 18:13
  • @keshlam, you seem very fixated on typos. – mreff555 Sep 16 '23 at 20:33

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