log cabin sheds without sticky out bits

[saaby93]

Looking at log cabin sheds on ebay. Why do they all have an interlocking end to each wall that sticks out about 100mm in both directions?
Can you get sheds without

[saaby93]

plug said:

Search for loglap sheds.

Thanks
How does log lap work - are they tongue and groove or can you get gets to let in water
in windy conditions