Sikagard-400 Enviroseal is a commercial-grade penetrating water repellent for concrete and masonry. If the name looks unfamiliar, that’s because it has changed twice: it was sold for years as Enviroseal 40, then as BASF / Master Builders MasterProtect H 400, and it now carries the Sika name.
| Type | Penetrating water repellent |
| Chemistry | Water-based, 40% alkyl alkoxy silane |
| Finish | Invisible, no change in appearance |
| Best for | Parking decks, bridge decks, ramps, plazas, exterior concrete and brick |
| Application temp | 40–110°F |
| Where to buy | Commercial construction-supply distributors (typically 5-gallon pails) |
What It Is
It’s a single-component, water-based sealer containing 40% silane. Silanes are small molecules that soak deep into concrete and react to form a water-repellent layer inside the pores, protecting against moisture, chloride (salt) intrusion and freeze-thaw damage without leaving a film. It’s used on parking garages, stadiums, bridge decks and other reinforced structures, and it’s listed as an Alberta DOT Type 1b sealer.
Pros
- High 40% silane content, the level many transportation specs call for
- Doesn’t change the look or traction of the surface
- Works on horizontal and vertical surfaces, indoors or out
- Water-based, with less odor than solvent-based silanes
Cons
- Sold mainly through commercial distributors, not big-box stores
- No oil or stain repellency; a silane alone mainly blocks water and salt
- Can’t be applied if temperatures will drop below 40°F within 12 hours
- The name changes make it harder to find and compare
Who Should Buy It
It’s a good fit for contractors and property managers protecting large areas of exposed concrete from road salt. Homeowners can get the same 40% actives level in a product that’s easier to buy and apply. See our best silane/siloxane sealers and best concrete sealers.
Application Tips
- Apply to clean, dry concrete with no standing water.
- Crack repair and joint sealants can go in before or after the sealer.
- Follow the label for coats and coverage, since porous surfaces absorb more.
How we reviewed this product: this review is based on the manufacturer’s current technical data and product listings, along with our experience with this type of sealer. Product details were last checked in October 2026; always confirm against the current label before you buy.