ᐅ Garden Shed/Moisture Issues with Flooring and Interior – A Common Problem?

I have installed a garden shed on a self-made paved surface in my garden.

The shed itself rests on pressure-treated frame timber. I still painted the wood and attached a 6mm (1/4 inch) thick rubber granulate strip underneath to ensure the wood doesn’t sit directly in damp water.

The strip is generally well seated everywhere, but there are some places where, for example, there is about 1mm (0.04 inch) of air gap around the paving. When it rains, some moisture seeps through here and through the joints into the garden shed. This doesn’t mean water is really running inside, but the stone does get wet.

Is this an issue that requires sealing from the outside with something like silicone, or is it fine to leave it as is? The garden shed is only used to store gardening tools.

Attached are two pictures for clarification.

Since it rained all night, here are some pictures of how it looks afterwards.

The moisture comes from below. This is normal. I would not seal that area to allow the humidity to circulate.

Thank you for the quick assessment.

I have the same issue with my steel garage on paving stones.
Water travels along the stone or through the substrate and spreads inside.
I still applied some sealing on the outside, and overall it has improved.

However, during the first 1-2 years, I also experienced rising damp in the middle of the garage when placing or laying larger items on the floor (mortar buckets/sacks). This gradually resolved over time.
The reduction at the edges may also be related to the decreasing moisture saturation in the substrate.