Bike Shed Base Problems

[chris101]

We bought a bike shed for our front garden and put it up today.
The advise that was given prior to purchase was we need a level base for the bike shed otherwise we would have issues with it closing and locking it.

I wasn't sure the shed based would be suitable however my wife was adamant that we would be able to get away with it.
Lo and behold, whilst the bike shed is now built, we have issues with alignment when closing/locking due to the uneven base.
We have installed the bike shed on slate slabs in the front garden which are intentionally laid at a gradient to allow rain water to flow away from the house.
This along with the natural surface of the slate slabs has caused the current faced problems.

We are able to close it however I have to put pressure on the sides each time I close it to get it to align up correctly.

What would be the easiest, quickest and most cost effective way of resolving the levelling of the floor?

Thanks

 

[Burnerman]

Pack the low corners up with thin pieces of roof slate Chris, until you get the base perfectly level.
You can then pack the bottom horizontals to spread the weight and fill the gaps.
If you dont have any bits of slate kicking around, Screwfix do plastic packers in a variety of thicknesses to a maximum of 10mm.
John