Liquid Rubber vs DRYLOK
Unlike most waterproofing match-ups, these two genuinely compete for the same job. One is rigid and becomes part of the wall; the other is flexible and stretches over it. The right answer depends on whether your wall stays still.
Alex Rivers
Home Improvement Editor
Last Updated
September 8, 2026
In This Guide
Ask one question before you buy either: does this wall move? A rigid coating on a stable wall is cheaper, tintable and rated for pressure. A rigid coating on a wall that cracks seasonally splits along the crack and takes your weekend with it.
1. What Each Product Actually Is
DRYLOK
DRYLOK, made by UGL, is a cementitious latex masonry waterproofer — Portland cement suspended in a latex binder. Brushed into bare masonry, the cement fraction reacts with residual moisture and free lime in the concrete, so the coating becomes chemically integrated with the top layer of the wall rather than sitting on it. That integration is what allows the Extreme formula's 15 psi hydrostatic pressure rating and its ten-year warranty.
It is applied in two full coats, needs bare and thoroughly prepared masonry, and dries to a slightly textured, paint-like finish that can be tinted or topcoated. Coverage runs about 75 to 100 square feet per gallon per coat on block.
Liquid Rubber
"Liquid rubber" covers a family of high-solids elastomeric membranes — Ames Blue Max and Liquid Rubber's foundation sealant are the two most commonly bought for basements. They are applied thickly by roller or brush and cure into a genuinely elastic membrane with substantial elongation: the cured film can stretch materially before it tears.
It bonds mechanically rather than chemically, tolerates a damp substrate better than DRYLOK does, and can be used on the exterior face of a foundation below grade as well as inside. The cured surface is rubbery and matte, and it will not take ordinary wall paint.
Head-to-Head Comparison
| Category | Liquid Rubber | DRYLOK |
|---|---|---|
| Type | Elastomeric membrane | Cementitious latex coating |
| Bridges hairline cracks | Yes — stretches across them | No — cracks with the wall |
| Published pressure rating | Varies by product | Up to 15 psi (Extreme) |
| Exterior below grade | Yes, designed for it | Primarily interior |
| Damp substrate | Tolerated by many formulas | Needs a dry wall |
| Paintable afterwards | No | Yes, and tintable |
| Cost per square foot | High | Moderate |
| Finish | Rubbery, matte, thick | Textured but wall-like |
3. The Question That Actually Decides It
Everything else on this page is secondary to one property: elongation. A cured elastomeric membrane can stretch by a significant percentage of its own dimension before it tears. A cementitious coating cannot stretch at all — it is rigid by design, because rigidity is what lets it integrate with the masonry and resist pressure.
So when a wall opens a hairline crack, which most block and poured walls do at some point through seasonal movement, the two coatings behave completely differently. The membrane stretches across the gap and keeps water out. The cementitious film splits along the crack, and water arrives through the split.
That is the entire decision, and it means the useful question is not "which product is better" but "has this wall cracked before, and is it likely to again?" Look for hairline cracks in the existing surface, for cracks in a previous coating, for stair-stepping through mortar joints, and for any history the house has of seasonal movement. A wall with that history wants a membrane. A wall without it is DRYLOK territory, and DRYLOK will cost less, look better and carry a published pressure rating.
One caution in both directions: a wall with wide, moving, or stepped cracking is a structural question, not a coating question. Neither product is the answer to a bowing wall, and covering the evidence makes the eventual diagnosis harder. Our basement crack repair guide covers which cracks matter.
4. By Use Case
Damp Interior Wall Being Finished as Living Space
DRYLOK. It costs less per square foot, it takes a tint or a topcoat so the wall can be a colour rather than a coating, and it holds a real pressure rating. Liquid rubber's rubbery finish would need framing and board over it, which is fine if that is the plan and wasteful if it is not.
Wall With a History of Hairline Cracking
Liquid rubber. This is the case it exists for. A rigid coating will fail at the crack no matter how well it was applied, and reapplying it every couple of years costs more in time than the membrane costs in materials.
Exterior Foundation During an Excavation
Liquid rubber, without hesitation. Exterior waterproofing works with the water pressure rather than against it, and elastomeric membranes are formulated for below-grade burial, cure seamlessly with no laps to track behind, and stay flexible through freeze-thaw. If the digger is already there, this is the right side of the wall to be working on — our exterior waterproofing guide covers the full build-up.
Basement That Never Fully Dries
Liquid rubber, on tolerance grounds. Several formulations are rated for application to damp masonry, which is a practical advantage in a wall that has not been genuinely dry in years. DRYLOK applied to a damp wall is one of the more common causes of early failure.
Retaining Walls, Planters and Water Features
Liquid rubber for anything holding water in, or anything that moves with temperature — a planter, a pond wall, a concrete water feature. DRYLOK for a large stable masonry retaining wall keeping soil moisture out, where the economics of covering a big area matter.
Whole Basement Perimeter on a Budget
DRYLOK, with liquid rubber reserved for the one or two walls that genuinely need it. Coating an entire perimeter in a high-solids membrane is expensive, and most basements do not have a movement problem on every wall. Our basement waterproofing paint guide covers the products across both categories.
5. Application and Cost
Applying DRYLOK
Strip the wall to bare masonry, wire-brush efflorescence off dry, vacuum, and fill cracks with hydraulic cement. Brush the first coat in hard with a masonry brush — rolling bridges the pores rather than filling them — then wait a full 24 hours and apply the second coat in the opposite direction. Both coats are mandatory: every published pressure rating assumes two.
Applying Liquid Rubber
Clean the wall thoroughly, but you do not need the same bone-dry, chemically-bare surface. Apply with a heavy-nap roller or a brush in two thick coats, respecting the recoat window on the label. The material is much thicker than paint and goes on more like a heavy mastic — expect to work slower and to use noticeably more product per square foot than you would with a masonry paint.
What It Costs
DRYLOK covers roughly 75 to 100 square feet per gallon per coat on block; a typical basement perimeter needs somewhere in the region of 16 to 20 gallons for two coats. High-solids liquid rubber covers considerably less per gallon because it is applied thickly by design, and costs more per gallon to start with, so the same wall can run to a multiple of the DRYLOK figure. That gap is exactly why the sensible strategy is to use the membrane where flexibility is genuinely required and the cementitious coating everywhere else.
How Long Each One Lasts
DRYLOK Extreme carries a ten-year warranty on properly prepared masonry, and in practice a wall that was stripped, brushed and given two full coats commonly goes well beyond that before anything needs attention. Its failures are almost never gradual: it either holds for years or it lifts within the first season because the surface underneath was not right. That makes preparation, rather than the product, the variable that determines the lifespan.
Elastomeric membranes fail differently. Buried on the outside of a foundation, protected from ultraviolet light and abrasion, a high-solids membrane is effectively a permanent part of the assembly. Applied inside, its enemy is mechanical damage — a shelf bracket, a scraped wheelbarrow, a dragged appliance — because the film is soft enough to gouge and a gouge is a hole. Neither product wears out in the way an exterior deck finish does; both are undone by specific events rather than by time.
6. Can You Use Both Together?
In one direction, usually yes. Most liquid rubber products will bond to a sound, fully cured DRYLOK coating, and several manufacturers explicitly allow it — useful when an existing DRYLOK wall has developed a crack and you want to add flexibility over the top rather than strip everything.
In the other direction, no. DRYLOK bonds by reacting with bare masonry, and a rubber membrane underneath prevents that reaction entirely. Nothing cementitious will hold on cured liquid rubber. This asymmetry is worth knowing before you start, because it means the membrane is effectively a one-way decision for that wall.
Always check the specific data sheet. Elastomeric formulations vary, and "liquid rubber" is a description of behaviour rather than a single chemistry — what one manufacturer permits over an existing coating, another may not.
There is also a sensible middle path that neither manufacturer advertises: treat the crack, not the wall. Bridge a known problem crack with a band of membrane a foot either side, let it cure, and then coat the whole wall with DRYLOK up to and over the edges of that band. You get flexibility exactly where the movement is and a paintable, pressure-rated surface everywhere else, for a fraction of what a full membrane would cost.
Common Mistakes With Both Products
Choosing on Price Rather Than Movement
DRYLOK is cheaper per square foot and irrelevant on a wall that cracks. Establish whether the wall moves first; the cost comparison only means something once both products are actually candidates.
Applying DRYLOK Over Paint or a Damp Wall
It bonds chemically with bare masonry or it does not bond at all. Old paint, efflorescence and residual damp are the three reasons it peels, and all three are preparation failures rather than product failures.
Coating a Whole Basement in Liquid Rubber
It is expensive, it cannot be painted, and most walls do not need it. Use it on the walls with a movement history and finish the rest with a cementitious waterproofer.
Assuming Either One Fixes Drainage
Water arriving after every rain, or coming up at the wall-floor joint, is a drainage problem. Gutters, downspout extensions and grading come first, then a perimeter drain if needed. Coatings handle seepage, not volume.
Skipping Crack Repair Because the Membrane Flexes
Liquid rubber bridges hairlines, not gaps. Anything wider than a hairline, and anything actively leaking, still needs hydraulic cement or a polyurethane injection before the membrane goes on.
Liquid Rubber vs DRYLOK: Who Wins?
Choose liquid rubber if: the wall cracks or moves, you are waterproofing the exterior face during an excavation, or the masonry never fully dries out. Its elongation is a property no cementitious product can offer, and on those walls it is the only one of the two that will still be working in three years.
Choose DRYLOK if: the wall is stable, the basement is being finished as living space, or you are covering a large area on a budget. It costs less per square foot, carries a published 15 psi rating and a ten-year warranty, and — unlike the membrane — it can be tinted or painted so the wall looks like a wall.
The Honest Bottom Line: This is one of the few waterproofing comparisons where both products are genuine candidates for the same wall, and the deciding factor is movement rather than quality. Rigid and integrated where the wall stays still; flexible and bridging where it does not. Most basements are best served by DRYLOK on the majority of the perimeter and liquid rubber on the one wall that keeps cracking — and by fixing the drainage before either goes on.
Frequently Asked Questions
Is liquid rubber better than DRYLOK?
On a wall that moves or cracks, yes — an elastomeric membrane stretches across a hairline crack where DRYLOK's rigid film splits with it. On a stable interior wall being finished as living space, DRYLOK is better: cheaper per square foot, tintable and paintable, and rated to 15 psi of hydrostatic pressure.
Can you apply liquid rubber over DRYLOK?
Usually yes, over a sound and fully cured coating — many manufacturers permit it. The reverse is not possible: DRYLOK must bond chemically with bare masonry and will not hold on a rubber membrane. Check the specific product data sheet, as formulations vary.
Which works on the outside of a foundation?
Liquid rubber. Elastomeric membranes are built for below-grade exterior use, cure seamlessly with no laps for water to track behind, and stay flexible through freeze-thaw. DRYLOK is primarily an interior product. If you are already excavating, the exterior face is the right side to waterproof.
Can you paint over liquid rubber?
Generally no — the cured surface stays rubbery and flexible, and ordinary wall paint either will not adhere or cracks as the membrane moves. A finished room over liquid rubber needs framing and board. DRYLOK is tintable and accepts a masonry-suitable topcoat once cured.
Which is more expensive?
Liquid rubber, clearly, per square foot. It is a high-solids product applied thickly, so a gallon covers far less than a gallon of DRYLOK, and it costs more per gallon to begin with. Across a full perimeter the difference is substantial, which is why it is best reserved for the walls that need flexibility.
Does liquid rubber stop hydrostatic pressure?
High-solids membranes resist substantial pressure and are used below grade for exactly that reason. But no interior coating solves water arriving in volume — a failed perimeter drain or a rising water table is a drainage problem. Coatings deal with seepage and dampness.
Can either be applied to a damp wall?
Liquid rubber is the more tolerant — several formulations are rated for damp, though not wet, masonry, which helps in a basement that never fully dries. DRYLOK needs a dry, clean, bare surface to bond, and applying it to damp masonry is a common cause of early failure.
Do you still need to fill cracks first?
With DRYLOK, always — it seals pores rather than bridging gaps. Liquid rubber bridges hairlines by design, but anything wider, and anything actively leaking, still needs hydraulic cement or a polyurethane injection before the membrane goes on.
Related Guides
Review
Best Basement Waterproofing Paint
Cementitious, acrylic, elastomeric and penetrating products compared.
Comparison
DRYLOK vs Flex Seal
The other DRYLOK match-up — and why it is not a fair fight.
Guide
Interior vs Exterior Waterproofing
Which side of the wall to treat, and what each approach costs.
The Bottom Line
Liquid rubber and DRYLOK are the rare pair of waterproofing products that really do compete for the same wall. The difference is rigidity: DRYLOK integrates with the masonry and resists pressure but cannot move, while an elastomeric membrane stretches over cracks but costs more and cannot be painted.
Decide on movement, not on price. A stable wall takes DRYLOK, two coats onto bare prepared masonry, and looks like a finished wall afterwards. A wall that cracks takes the membrane, and will still be dry when the rigid coating would have split. And whichever you choose, if water is arriving after every storm, the coating is the last thing to buy — the drainage outside comes first.
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About the Author
Alex Rivers, Home Improvement Editor
Alex has spent over a decade working on residential and light commercial property maintenance, and now tests every tool, coating and machine that appears in these guides personally.