Hi chabang-- I just installed those same Ann Sacks pennyrounds on my floor in Rice Paper (white with a gray halo). Love them so far-- and I was surprised how affordable they were despite being Ann Sacks. We almost used that gorgeous Cornflower blue color, and I bet yours are going to be great. Anyway, to answer your question... To me, the beauty of those tiles is the halo effect and the shape, so I'd want to choose a grout color that highlights those things. I went with a gray grout because I didn't want the hassle of cleaning white. But, in hindsight, I regret that the grout color blends so closely with the halo, and that there isn't more contrast. I also am not a huge fan of dark grout lines. Those things might argue against using the Waterfall, and might suggest using a color closer to the Biscuit. On the other hand- the benefit to using grout with little color contrast was that it masked imperfections in the grout job. We DIYed the installation, and found it was challenging to get the mosaic laid evenly depth-wise in the thinset. The other benefit to darker grout is that its easier to keep clean. Perhaps since you already bought the Waterfall you could do a test sheet? Also, I don't think you need Waterfall caulk, the Warm Gray should cover it. Good luck!

Good question and comments. This is often the leakiest transition in most homes, mainly at foundation to framing. The typical sill sealer used here is too thin. Best to use thicker sill sealers, gaskets or caulk the top and bottom of thin sill sealer during installation. Since most architects and builders miss this detail, it can help to caulk the sill to the foundation while there is still access from the inside. If you can't reach the sill plate, it can still help to caulk the drywall to slab, subfloor or finished floor. This can help mitigate moisture, bugs, dust and energy loss. If your wall cavities aren't spray foamed, dense packed, or SIPS, then they are probably acting as air pathways to some degree. Air can be pulled through them from the basement, attic or floor framing cavities and with it can come dust. Stopping this sort of unwanted air movement is better from a moisture management standpoint as humid air traveling through cold building cavities leads to hidden moisture problems. Acoustical caulk, urethane caulk or high quality one part spray foam are good materials for sealing. I wouldn't bother with Dap's and other water based spray foam, I've seen it turn to dust with light touch, just days after installing.

My advice about caulk in general is this: water does find its way behind the best caulk jobs. So you must leave the water some way out, or you'll be replacing wood within a few years. We just replaced all the brick mould and a few window sills on a 9 year old house, because there was an abundance of caulk trapping water. Where to leave areas of no caulk: bottoms of vertical trims that rest on horizontals, up under protected areas (under soffits, etc.) This is a shed, so I assume you are caulking for a seamless appearance rather than energy efficiency, so you can really take the "less is more" approach. I would remind people that barns never rot away for lack of caulk. The carpentry should be tight enough so that paint seals the woodwork joints, and caulk should basically be used where dissimilar materials intersect, such as wood/masonry, or wood/metal. Casey

You can ignore any advice you want. You have a change of plane there. It is industry wide specs that call for a silicone joint at all change of plane. Care not what the handyman used or is saying, its obvious you doubt their novice advice and its obvious by the quality of the work they are incompetant. Your big concern now is the proper way in which you remove all residue so Silicone can bond properly and so that you dont leave behind any MOLD prone residues under the new silicone install. So many clowns come here with mold under their poor attempt to correct a change of plane by improperly cleaning out latex based caulks and replace with the proper material. Then later claim their un-mold-abale silicone is producing mold. Its an age old mistake and ive told you exactly how to approach the repair. Now im not looking for likes here or thank you's . But if you speak to any one single tile professional that follows the TCNA/ansi youll see what im saying. The way forward is in your hands. Acetone . Use it. and since you are spanning a larger than industry standard 1/8" joint you need to choose your flash point and type silicone properly theres no less than hundreds of 100% silicone blends/types out there.