What sealer to use
Recommended sealer: Miracle Sealants 511 Impregnator, Water Base — https://www.homedepot.com/p/Miracle-Sealants-511-Impregnator-Water-Base-511DEPQT6/300247617
Use a water-based sealer. Before treating the whole base, test a small area first and confirm you are happy with the result.
Do I need to seal my base?
Yes. We recommend sealing every base regardless of color, because it makes the surface easier to keep clean.
If your base is any color other than white, sealing will also make the color look richer and more vibrant. This is especially noticeable on graphite.
Why we recommend sealing
Sealing a CASTICO base is not about waterproofing or durability. The material is non-porous, so it does not need to be sealed in order to perform.
We recommend sealing for two reasons:
Easier cleaning. A sealed surface releases soap residue and soil more readily, so routine cleaning takes less effort. This applies to every color, including white.
Better color. On any color other than white, sealing deepens and enriches the finish. The difference is most noticeable on graphite.
In short, it is a cleaning and appearance recommendation rather than a protective one.
Why does a non-porous product need a sealer?
It does not need one to be waterproof — the material is already non-porous and will not absorb water.
Sealing is recommended because it makes the surface easier to keep clean and improves how the color looks. It is not sealing anything out.
The sealer label warns against silicone. Is that a problem?
No. That warning refers to silicone tile sealer, not the waterproofing silicone used at the joint between your walls and base. The two are different products, and the recommended sealer is fine to use on a normally installed CASTICO shower.
Can I use a solvent-based sealer?
We have not tested solvent-based sealers on our products and cannot recommend one, as there is a possibility of a reaction with the surface. We recommend a water-based sealer instead.
If you have already purchased a solvent-based product and intend to use it, test a small, hidden area first and wait to see the result before treating the full base.
When to reseal
Reseal after any buffing or polishing of the surface, so it stays easy to clean.
Beyond that, resealing periodically as part of normal upkeep will maintain both the cleaning benefit and the color depth.