Your greenhouse is gorgeous! And it would be amazing to have a year-round place to grow veggies.

I am not an expert in this area, but will tell you what a client of mine did, and her reason. I'm sure I’ll be corrected if its inaccurate. There are many gardening experts on here.

I‘d do a large format tile that could be power-washed if necessary. I was told of a scenario where a disease happened in the plants and she was able to disenfect and powerwash the whole inside (assuming there is a drain too). Even without spraying it down, I think you'd want to use the most mildew resistant materials. And easy-to-clean is always a good priority. I understand you dont want to take away from the gorgeous exterioir, but there's is an almost unlimited number of tile designs that would go with anything.

nice project!

Details thank you for the info. Good point. This GH is 50% she-she’d and 50 growing. Yes has a drain. Will have heat but due to our super cold winters prob won’t use in Jan and Feb. I’m hopeful someone can suggest a porcelain tile that can take cold and heat for that matter that would work in here. I’ve looked at lots of tiles but cannot imagine a wall covered with them for some reason.

I would do the interior walls the same stone as the outside.

For floor this idea would be my top choice.

https://www.houzz.com/products/somertile-kings-17-63-x-17-63-ceramic-floor-and-wall-tile-damero-prvw-vr~46759734

Dawn, I understand that - I am in Michigan. It sounds like a great she-shed place to visit when it's still chilly outside but the sun will be warm enough to make a cozy book reading spot!

I would always defer to a tile expert for the exact specs on a particular option - or maybe visit a local showroom to get this info. There are different ratings for the hardness or durability of a tile listed just like there is for COF (slip resistance). In general I would say you would want to steer clear of ceramic, as it isn't going to be as strong and able to withstand the extreme temperature and humidity variations. Porcelain is more dense and wont have as much of an issue with freeze/thaw expansion and contraction (and then cracking).

Check out Crossville Tile. They have a lot of nice well-made, larger format neutrals that wont fight your beautiful stone and provide a nice backdrop for whatever you decide to do inside your space. They even have an option to search for outdoor rated products. Here is one option with a nice subtle pattern (and looking at the description, the leathered texture sounds amazing too!). https://www.crossvilleinc.com/Products/Owen-Stone

Edited to add - you could do as suggested above and continue the stone you have on the exterior as the base material inside as well. It's such a small section of wall that it would look great too!

Thanks for all the info!! Yes we have talked to a tile expert already. But good tips. Have a Happy Thanksgiving!!