Those things normally last a long time, like 15-20 years. You just need to take a look at it after 15 year every year to make sure it has no obvious big crack. Normally it last way longer than that.
-jeffrey815(Smartiecat);
2020-7-29(#13113497@0)+1
And normally if you want to redo it, you need to remove the old one first. Rather than just apply on top of it...
-jeffrey815(Smartiecat);
2020-7-29(#13113551@0)+1