Metal Shed - to stop foxes getting in

Concrete floor

As gamekeepers do, dig a channel around the perimeter of the shed. place chicken wire from knee height down into the channel. Fix at the top edge and bend the bottom outwards. If a fox begins digging it will only get to the chicken wire underneath.

I think the more helpful answer would be to ascertain firstly what you are keeping in the shed ? Why are they breaking in ? Have you got chickens or something? Foxes kill poultry for fun not hunger. If you have chickens you might want to think about a rooster as they are extremely territorial and will protect his clutch or group of birds ! If you are keeping feed or something appetising to the fox maybe you should consider moving the attraction to a secure form of storage? Guard dog is a good option for land owners. Metal sheds are readily available to view on Google. Chicken wire buried under the parameters is always a good deterrent as Foxes can't dig. Hope that helps.

Having put in fox proofing before, dig a channel, and install fine mesh as a foundation under it and pin it to the base. Alternatively, a concrete type foundation or hard foundation will do it.