How do I make tiles erased when something collides with them?

Im making a game with many objects used as walls, so to optimize performance i need them to be a tilemap. However, no matter what I do the tiles wont erase with any method. Help would be appreciated!

Try reading the doc first.

https://www.construct.net/en/make-games/manuals/construct-3/plugin-reference/tilemap

A few things is that collisions can be enabled/disabled on individual tiles in the editor. So make sure that data is set up correctly. Also erased tiles always count as "not colliding".

If that's set up correctly then also make sure you're computing the correct tile indexes.

If that's all correct then just use one of the many "erase tile" actions.