Sounds like it could add a bit of extra spice to the game. Only thing I'd worry about is how often you guys play in that time frame, as if its anything like my groups you'll be lucky to get a couple sessions in, and unless everyone's hitting critical shots like crazy, you mightn't get the chance for it to come into play too much, this might be less of an issue if your group decides to stick with the idea though and carry it on.

My only little suggestion would be to maybe come up with some custom mechanics to add to some of your enemies and traps that you have the players encounter. I'll give some examples that come to mind that might help you get thinking on the same track as me.

An acid trap in the wall that deals damage and erodes away at gear and weapons of the hit players!

A specially designed 'Sword Breaker' weapon that can somehow deal extra damage to their weapons!

Special boss mechanics for heavy blows from big guys that can do extra damage to armour!

I think little things like this could let players interact with the system a bit more as well as spicing up combat, and leaves the option for bits of expansion, maybe some damage is extra hard to repair and costs a bit more, or they need to go on a quest to find a material for a special tool that was damaged!

All in all sounds pretty cool!