There are two houses built twenty years ago, which have a classic six-foot ship-lap fence on the boundary in the back garden.
House #1 20 yrs ago installed classic shed along the boundary, close to the fence. House #2 still just has a patio.
The #1 shed was showing its age after 20yrs, and has been removed, revealing that much of its demise was caused by lack of access for maintenance to the rear (too close to the fence) and the fence is so rotten you can poke a hole in it with finger.
Occupants of #1 wish to install a brand new shed, and have suggested to #2 that it would be in both of their interests that the back of the shed became the structure facing #2's patio.
But #2 are insisting they replace the fence (which is theirs) with a new one.
What should #1 use to protect the back of their brand new shed, one inch away from the brand new fence, to avoid the ongoing maintenance issues. A liberal coating of Cuprinol won't last the next 20yrs.
Maybe some sort of plastic membrane glued to the back of the shed?
Suggestions welcome.