Concrete may appear dense and solid, but it is naturally porous. This means water, vapour, and dissolved salts can move through it over time. If not properly managed, this moisture movement can affect both the concrete itself and any materials applied to it.
This is why membranes, sealers, and moisture barriers are commonly used on slabs, walls, balconies, and wet areas: they form a protective layer that stops water from penetrating and causing problems.
Every risk has a solution. See our concrete moister barrier range built to handle them all.
A concrete surface membrane is a protective coating applied to a slab to prevent water, moisture, and chemicals from seeping in. It protects the concrete itself as well as any finishes, floor coverings, or structural elements attached to it.
These membranes can be applied as liquid coatings, sheet membranes, or resin systems:
While surface membranes provide excellent moisture protection and durability, they can be labour-intensive, require skilled installation, and in some cases may alter the appearance of the concrete or add cost, making them less practical for every project.
A penetrating barrier (such as our DeepCure – Cure & Seal) is a liquid treatment that soaks into the pores of concrete and chemically bonds with its structure. Unlike surface coatings like epoxy or acrylic, it works from within rather than sitting on top, providing internal protection against water, oil, and contaminants.
Once absorbed, the sealer forms an invisible, hydrophobic shield that blocks & repels moisture while allowing the concrete to “breathe,” letting trapped vapor escape. This reduces surface deterioration, cracking, and freeze-thaw damage without changing the natural look of the concrete.
By strengthening and protecting the concrete from the inside out, a penetrating barrier offers long-lasting, invisible protection that keeps slabs durable, resilient, and low maintenance.
Aspect | Surface Membrane | Penetrating Barrier |
| Location | On top of the hardened concrete surface | Within the slab or directly below it |
| Installation time | After the slab is poured and cured (often before finishes or as remediation) | During construction (at pour stage or under‑slab prep) |
| How it works | Forms a coating/film near the surface to block upward moisture and protect finishes | Blocks or greatly reduces moisture movement through or under the slab as it forms |
| Protection focus | Primarily protects floor coverings, adhesives, coatings, and top surface zone | Protects the slab‑finish system from ground/sub‑slab moisture overall |
| Depth of effect | Mostly the surface and top few millimetres | Acts through the slab thickness or at the slab–ground interface |
| Vulnerability | Exposed to wear, traffic, preparation damage, and detailing issues at joints | As penetrating barriers do not stop floods from traveling from room to room, they are now considered a wet area waterproofing system |
| Relation to finishes | Directly interfaces with and conditions the surface for floor finishes | Creates a base condition so the slab is less prone to moisture problems overall |
Need a quicker breakdown? Check out our earlier post comparing them here.
DeepCure is a penetrating barrier, not a surface membrane. Unlike membrane-type curing compounds that form a layer on top of the concrete, DeepCure works from within the slab. When applied, the translucent, water-based liquid penetrates the concrete and reacts with the free alkaline to form a gel inside the capillaries and microfractures. This reaction locks in moisture, densifies the concrete, and creates a permanent internal barrier that prevents water and contaminants from migrating through the slab. Because it works inside the concrete rather than on the surface, DeepCure does not leave any film or residue, meaning it won’t interfere with coatings, adhesives, or floor finishes.
Our DeepCure moisture barrier retains over 95% of slab moisture for 28 days (tested to AS3799 standards), assisting in curing, preventing efflorescence, and improving surface hardness and abrasion resistance. Its internal penetration also makes it resistant to damage during construction, allowing tradespeople to work on the slab without compromising its effectiveness. The result is a durable, long-lasting moisture barrier that strengthens the concrete and provides fail-safe protection from moisture and contaminants, while leaving the natural appearance of the slab unchanged.
If you want to make a real difference to the durability and performance of your concrete slabs, now is the time to act. Avoid the costly and time-consuming fixing process. Get in contact with our team today to discuss how we can provide the right solution to protect your slabs, prevent moisture issues, and ensure a long-lasting, high-quality finish for your project.
