Crystalline Waterproofing Explained: How It Stops Concrete Leaks

You’ve had someone look at a leak in your building, and the quote says “crystalline waterproofing system.” Maybe it names Kryton Krystol. You’re nodding along, but what does that actually mean? Is it a paint? A sealer? Something that goes on the outside?

Crystalline waterproofing is how we stop most of the leaks we deal with, so here’s a plain-language explanation: what it is, how it’s different from coatings and membranes, the products we use, where it works best and, just as important, where it doesn’t. For how we apply it on the job, see our crack repair and waterproofing page.

What crystalline waterproofing is

Concrete looks solid, but under a microscope it’s full of tiny pores and channels (capillaries) left behind as the concrete cured, plus hairline cracks. Water moves through those paths, especially when it’s under pressure from wet soil.

Crystalline waterproofing fills those paths from the inside. The products contain active chemicals that react with water and with unhydrated cement particles already in the concrete. That reaction grows insoluble, needle-shaped crystals inside the pores and micro-cracks. The crystals block the paths water would use, so the concrete itself becomes the waterproofing barrier.

Kryton, which makes the Krystol products we use, puts it this way: Krystol technology “reacts with moisture to form insoluble needle-shaped crystals that fill capillary pores and micro-cracks in the concrete and block the pathways for water and waterborne contaminants.” Kryton also says that any moisture introduced later on will start crystallization again (Kryton, Krystol T1).

Two things follow from that:

• Water is part of the process. Crystalline materials need moisture to work, so a wet wall or an active leak isn’t a problem to wait out. It’s the right condition for the treatment.
• It’s in the concrete, not on it. There’s no separate layer to peel, puncture or wear off.

How it differs from coatings and membranes

There are three broad ways to keep water out of concrete, and it helps to know the difference.

Membranes are sheets or thick fluid-applied layers bonded to the surface of the concrete, usually on the outside (the positive side, where the water comes from). Applied properly at construction, they work well. But they’re a separate layer. They can be punctured during backfill, torn by settlement, debond from the concrete over time, or simply be impossible to reach once the building is up.

Coatings and sealers are rolled, brushed or sprayed onto a surface. Many work fine on sound, dry concrete. On the inside face of a leaking wall, with water pushing from behind, a surface coating tends to blister, lift and peel.

Crystalline waterproofing becomes part of the concrete. Because it works inside the pores rather than as a film on the surface, it can be applied to the wet side or the negative side, the inside face opposite the water. Kryton describes its Krystol T1 treatment as usable on either side of the water pressure. That’s what makes waterproofing concrete from inside practical on existing buildings, where the outside is buried. For more on that choice, see interior vs exterior waterproofing.

The products we use and what each does

We use Kryton’s Krystol system. Kryton is based in Vancouver, B.C. (Kryton, About). Here’s what each product does on a job:

• Krystol Plug. A rapid-setting hydraulic cement used to stop flowing water. It’s pressed into a cut-out crack or hole and sets in a couple of minutes, which lets us stop an active leak before the main repair. It’s part of Kryton’s Krystol Leak Repair System.
• Krystol T1. A surface-applied crystalline slurry treatment, brushed onto prepared concrete. Where more protection is needed, a further Kryton crystalline coat goes on over it. We use it on cracks and joints and across areas of concrete that need treatment.
• A Kryton crystalline top coat. A high-strength crystalline coating used to resurface and repair concrete, including as a waterproofing parge coat over spalled or honeycombed concrete.
• Plasti-Patch repair mortar. Used to rebuild damaged or missing concrete as part of the repair.

Where a crack’s width or movement calls for it, we also use compatible injection alongside the crystalline materials.

How a typical crystalline repair goes

1. Find every active leak path: cracks, cold joints, tie holes, honeycomb and penetrations.
2. Cut the leaking crack or joint out into a clean channel (a chase).
3. Stop running water with Krystol Plug.
4. Pack the chase with crystalline repair material.
5. Apply crystalline treatment to the surrounding concrete.
6. Inject any crack that still needs it.

Where it works best

Crystalline waterproofing is at its best where concrete is rigid, below grade and wet, and where you can’t get to the outside.

• Elevator pits. The lowest point in the building, often sitting in groundwater, with an outside face you’ll never reach again. This is classic negative-side work. See our elevator pit waterproofing page.
• Sumps. Sump pits and the pipes and barrel rings around them are often installed with little or no waterproofing, so water backs up where it shouldn’t. Read about our sump repair.
• Parkades. Leaking cracks, cold joints and below-grade walls, repaired from inside the parkade.
• Foundation walls. Basement leaks through cracks, the floor-wall joint and pipe penetrations, without digging up the yard.
• Tie holes and cold joints. Two of the most common leak points in poured concrete, and well suited to chase-and-pack crystalline repair.

All of this matters more here than in drier places. The Lower Mainland and Fraser Valley get a long, wet season, and many buildings sit in low-lying ground where groundwater is high for months at a time. Below-grade concrete in our region spends a lot of its life wet, which is exactly the condition crystalline materials need.

Limits (be honest)

Crystalline waterproofing is a strong tool, but it isn’t the answer to everything. Here’s where it falls short.

Moving or structural cracks. Kryton’s own data sheet for Krystol Plug says it is for rigid structures and may not reliably seal cracks that experience variable loading or repeated movement. A crack that’s still opening and closing, or one that’s offset or growing, needs an engineer first, and may need injection or a structural fix before waterproofing.

Drainage and grading problems. If gutters overflow, downspouts dump against the wall or the ground slopes toward the building, crystalline treatment will stop water at the concrete but won’t fix the cause. Deal with those too.

Surfaces that need a traffic membrane. Parkade decks, plaza decks and other surfaces with vehicle or foot traffic exposed to weather usually need a membrane or traffic coating on top. That’s a separate, top-side job a contractor may recommend alongside leak repair; ask us whether it suits your building. This article covers leaks through the concrete from below.

Non-concrete materials. Crystalline technology relies on cement chemistry. It’s made for concrete and cement-based materials.

Common questions

Does crystalline waterproofing work on old concrete?

Yes. The chemistry reacts with water and unhydrated cement particles that are still present in older concrete, and Kryton says its T1 treatment can be applied to new or existing concrete. The concrete does need to be sound. Badly deteriorated, spalled or honeycombed areas are cut back and rebuilt first, then treated.

Can it be applied when water is actively leaking?

Yes, and we prefer it. Running water shows us exactly where the leak path is. We stop the flow first with Krystol Plug, a rapid-setting hydraulic cement made for flowing water, then pack and treat the crack with crystalline materials. Because those materials need moisture to react, a wet crack is the right environment for them.

Is it the same as a sealer from the hardware store?

No. Most hardware-store sealers form a film or fill the surface. On a leaking wall, water pushing from behind can lift them off. Crystalline products react inside the concrete to grow crystals in the pores and cracks, so the concrete itself resists water. They’re professional products, cut into and packed into the concrete, not painted over it.

How long does it last?

Crystalline treatment becomes part of the concrete rather than a layer that wears off. Kryton says that any moisture introduced over the life of the concrete will start crystallization again. How a particular repair holds up depends on the structure, especially whether cracks are still moving, which is why we assess that before we recommend anything.

Is Kryton a Canadian product?

Yes. Kryton International was founded in Vancouver, B.C., in 1973 and is still headquartered there, according to the company. Its Krystol crystalline technology is used on projects around the world, and the products we use come from that Krystol line.

Book a free inspection

If you’ve been quoted a crystalline system, or you have a leak you want looked at, we’re happy to walk you through what it would involve for your building. We repair concrete leaks from the inside across Vancouver, Burnaby, Richmond, Surrey and the Fraser Valley. Read more about our crack repair and waterproofing, then call (778) 686-2221 (Mon–Sat, 8:30 AM–5:00 PM) or request your free inspection.