Sealing walls and expanding

[basuranephilim]

Hi there. Me and my consorts managed to get our palisade up and have a semblance of what might become a decent place to live.
I've sealed the gate posts, for obvious reasons, but i'm reluctant to seal the corner posts, since we (might) want to expand at some point.

My question: how do I deal with griefing / sealing / expansion in such a way that prevents me being griefed but allows me to expand when ready?

As I understand it, sealed posts are non intractable, which puts a stop to expanding from the posts.
Help much appreciated =)

____
Edit
Much appreciate the help!

[Teleskop]

if the pallisade is all on claim its impossible for anyone to expand it,unless he has claim rights

[basuranephilim]

if the pallisade is all on claim its impossible for anyone to expand it,unless he has claim rights

Even if they have Vandalism unlocked?

[Teleskop]

if the pallisade is all on claim its impossible for anyone to expand it,unless he has claim rights

Even if they have Vandalism unlocked?

yup