Advice needed: Building Foundation for a Shed?

[Johnnie1801]

Hi Guys, I ordered a new garden shed last week and I was just looking for a bit of advice on building the foundation for it. The base needs to be about 155"x120" (390x300 cms). Normally I would make a concrete slab but I'm thinking it might be more cost effective to build a deck made of composite/lumber boards. The shed will weigh about 1100 lbs (500 kgs).

All advice is kindly appreciated :)

Jon

[mqqn]

My shed, also 10x12', came with treated lumber on the floor timbers, along with the floor sheathing.

Since in my locale if you put in a slab it will raise your taxes as an improvement to the property, I chose to have 10 ton of unwashed large landscape stone brought in, and then I leveled it onto the area that would become my pad, and ran my truck back and forth over it to get it set into the ground.

The shed has been in place there for 15 years with no trouble at all, the timbers look great because the rock allows the ground to drain in that area very well, keeping the shed high and dry.

I would say that 10 tons of stone does not look like much until you begin trying to move it around with a shovel. ;^)

Good luck with your shed!

best

mqqn

[SpyderNut]

mqqn has some good adice regarding stone vs. concrete. My brother is a contractor and has done several pole barns either way (concrete vs. stone). Both have their merits, although concrete is perhaps the best route to go when considering longevity of use and durability (not to mention keeping vermin out). That being said, a garden shed doesn’t usually see a lot of traffic. :) I have a simple woodened-floored shed built by a previous owner (likely to save on cost and hassles with building permits). It works well, although I'm not sure how long it will last. Time will tell. I'd say if you can afford concrete, do it. If not, stone or treated lumber--like 3/4 marine grade plywood, is a good option.

[bdblue]

I have seen sheds built several different ways. Obviously a properly built concrete slab will be best in several ways. It will last longest, it will perform better, it will anchor the shed and resist wind loads better. (On our TV news yesterday they showed a guy whose shed was laying on its side from very heavy winds.)
I saw some photos online last week of a shed foundation made of wood joists setting on concrete pads, maybe concrete blocks. Something built like this would not be anchored to the ground and would be susceptible to blowing away in strong winds. It may be that lots of people build sheds this way. I don't have any experience with the lightweight metal sheds that you can buy at home improvement stores. I think they just set on the ground and it wouldn't take much for them to blow away.

[spyderg]

Does the shed have a floor? If so what kind? I put in a small shed, (5'x6') last summer, just a HD plastic/resin thing but it has a very solid floor. I just made a wood frame, put down some limestone, a layer of plastic shaped liked egg cartons and another layer of limestone. Packed it down and built the shed on top and screwed it to the wood frame that was staked into the ground. The shed itself doesn't weigh much but It's got 500lbs or so of junk in there and it sits in a part of the yard that gets and stays pretty wet all spring. We also get very strong winds and It hasn't budged and I don't expect it will.