What is the best adhesive for installing ceramic tile for the shower floor?

I'm looking for specific brands/products that we can purchase at Home Depot or Menards.

Recently got a shower done professionally from a local tile shop. The guy they contracted out to lay the tiles used type 1 on all the shower walls. Only after he finished did I find out there’s some controversy over whether this is actually okay.

I asked him about this and he said “I used the painted moisture barrier so that the type 1 would be safe to use. If using type 1 on a waterproof membrane that doesn't repel moisture that could cause issues but I used the roll on paint for that purpose. Type 1 isn't good if it's exposed to water so outdoor places big no no, in showers as long as you used a moisture absorbent and waterproof membrane you're golden!”

I contacted the tile company who hired him, and they said they wish he hadn’t used it, but technically you can and it should be fine. They have a guarantee for 1 year after installation, and he said if anything goes wrong it would be in the first year anyway.

Should I trust what they’re saying?

If you're looking for the best tile adhesive for a long-lasting and secure tile installation, it depends on the type of tiles and surface you're working with. Here are some recommendations:

✅ Cement-Based Adhesive – Best for ceramic & porcelain tiles, ideal for floors & walls.
✅ Epoxy Tile Adhesive – Super strong, waterproof, and great for high-moisture areas like bathrooms.
✅ Ready-Mix Adhesive – Perfect for small DIY wall tile projects, easy to use.
✅ Polymer-Modified Adhesive – Offers extra flexibility & bonding strength, great for larger tiles.

For outdoor areas, go for Megicrete waterproof and weather-resistant adhesives to prevent damage. Also, proper surface prep and curing time are key for a durable installation!