Should I still make a foundation for a pre-made shed that will be placed on backyard concrete?

Question

I am planning to purchase a shed from Wayfair, but I see a lot online about needing to build a base with concrete or gravel.
If I get a 4x6 or 6x8 metal shed, do I still need to build my own foundation base when it will be placed on flat concrete ground (no dirt)?
It will be in residential California and weather of periodic minor rain and wind.

Answer 1

It depends on what you want to store in the shed. A concrete floor is better than dirt. You can use a pre-existing concrete floor. However, one would normally allow drainage around it to stop water getting. If you are storing anything on the floor, you dont want it getting wet.

In the absence of drainage, I would raise the floor. I had a similar situation and in heavy rain, water was coming in. So I put down pallets on the concrete floor to keep things above the water. It was the cheapest and easiest thing to do, considering I had some to get rid off.

Answer 2

I think your question is, do you need a foundation to place the shed.

In most cases the answer is no. The shed is self contained and is not so heavy that it needs a foundation. ( On concrete is fine.)

The best way to find the definitive answer is to refer to the manufacturer for their installation recommendations.