Cracked grout at shower floor/wall intersections - how much do I remove?

Question

The grout where the walls and floor meet in our tile shower was deteriorating. My project for the week is removing it and sealing the shower, then replacing with silicone caulk.

One big concern I have is how much grout to remove. I've got it now where there is a nice 90 degree angle between the surfaces, whereas before it was a 45 degree slope of grout. (I'm using a handheld grout saw just for this small area.) Also, when done, should I seal the remaining grout before caulking?

Here you can see a pic of halfway through a grout line, before and after.

In some places this is the best I can do (wall and floor almost flush), in others there is still more grout. Do I just stop here? I'm worried about going to deep and hitting the wall behind or the shower pan.

Here is an example of where I'm at now.

Answer 1

Pretty 'rustic' finish between the wall and floor! General rule is to use silicone at every change of direction (wall to floor or wall to wall in a corner etc.) or change of material, (tile to wood or tile to glass etc.). As you said, aim for a clean square corner or 90 degrees between the floor and the wall. No need to go deeper than the surface of the tile. You'd have to go pretty hard (or be using powered tools) to hit the substrate under the tiles, so don't worry about that. Cleaning and sealing the grout (plus the tiles if they are porous) before the silicone sealant is best practice. Silicone is usually the last job (unless you're doing something silicone will not stick to).