Preventing spread of crimson/hallow?

[Noodlesinthehood]

So I recently started mining 3-block wide holes to stop the spread of the crimson and hallow before I enter hardmode. I’ve heard some people say to make 6-block gaps, but I also hear that 3-block wide holes work as well. I don’t want to spend too much time mining these holes, so what should I do?

 

[Sigma90]

Three block gaps are the minimum. Some people go for higher gaps for aesthetic or personal reasons and some line the gaps with wood or another non-convertible material.
Keep in mind that vines and thorns can further spread the C/C/H, so consider removing any grass near the gaps to stop vines and thorns from growing.

 

[Noodlesinthehood]

Three block gaps are the minimum. Some people go for higher gaps for aesthetic or personal reasons and some line the gaps with wood or another non-convertible material.
Keep in mind that vines and thorns can further spread the C/C/H, so consider removing any grass near the gaps to stop vines and thorns from growing.

Alrighty, thanks.

 

[The Storm]

What I do is make a 4 block wide gap and fill the side with the evil/ hallow with a non-convertable block such as wood or stone slabs, this is so I can still travel through it. Also making a bunch of 4 block wide hellevators with non-convertable blocks on each side will help as well.

 

[Sigma90]

Just to clarify: Non-convertible blocks will prevent thorns and vines growing, but it doesn't block the spread of C/C/H itself. If you had a three block setup like:
Stone | Wood | Crimstone
The Crimson would eventually jump over the wood and infect the Stone. You would need (at a minimum):
Stone | Wood | Wood | Wood | Crimstone
To make a hellvator out of it:
Stone | Wood | Empty | Empty | Wood | Crimstone
(The materials here are just examples.)