Most exterior concrete, especially driveways and walkways exposed to freeze-thaw cycles or road salt, benefits from sealing, and a penetrating sealer is usually the right choice because it protects without sacrificing traction. The exceptions are brand-new pours that need time to cure, already-damaged slabs that need repair first, and decorative surfaces where a film-forming sealer is chosen on purpose for colour. This guide covers sealer types, costs, timing, and how to check what you already have.
TL;DR:
- Penetrating sealers typically last three to five years, acrylic coatings one to three, and premium polyurethane or polyaspartic coatings five to ten years or longer.
- Wait at least 28 days after pouring, then allow a dry 24 to 48 hour period before and after application, within the product’s temperature range.
- Glossy film forming sealers can become slippery on wet slopes and pool decks; add a traction additive if appearance requires that finish.
- Water beading suggests an existing sealer, while tape that lifts flakes signals a failing coating that should be stripped before recoating.
- Ask contractors to itemize square footage, sealer type, coats, and preparation; cleaning, degreasing, and crack filling can cost more than the product.
Table of Contents
- What sealing actually does to concrete
- Why sealing helps: durability, stains, and curb appeal
- The real downsides of sealing concrete
- How long sealers last and what resealing actually costs
- When to seal new concrete, and when to leave it alone
- How to tell if your concrete is already sealed
- Keeping sealed and unsealed concrete looking its best
- Field tips for getting sealing right the first time
- Our take on choosing a sealer
- Professional concrete cleaning and sealing from YearLong
- FAQ
- Sources
What sealing actually does to concrete
Concrete is porous by nature, and that porosity is the root of most of the damage you see on driveways and patios. Water gets into the pores, freezes, expands, and over repeated cycles that pressure causes scaling, cracking, and surface flaking, a process Cement describes as a central durability concern in cold climates. Sealing does not change the concrete itself. It changes how much water and chemical exposure actually reaches those pores.
There are two broad sealer families, and the difference between them matters more than the brand on the bucket.
Penetrating sealers (silane and siloxane) soak into the surface and react chemically within the pores, leaving the concrete looking almost unchanged. Silanes typically penetrate deeper and suit dense concrete, while siloxanes have slightly larger molecules and work well on medium-porosity surfaces, and both let moisture vapour escape from below, which is why they’re called breathable.
Film-forming sealers (acrylic, epoxy, polyurethane) sit on top of the slab and create a continuous surface coating. They add gloss, enhance colour, and resist stains more aggressively, but that coating also blocks vapour transmission and can turn slick when wet.
- Penetrating sealers suit driveways, walkways, and garage floors where traction matters most.
- Acrylic sealers suit decorative patios and pool decks where appearance outweighs slip concerns.
- Epoxy and polyurethane sealers suit garage floors and commercial surfaces that need heavy chemical and abrasion resistance.
Concrete Network’s overview of penetrating sealers notes that penetrating products are commonly recommended for driveways and walkways precisely because they provide protection without changing how the surface behaves underfoot.
Why sealing helps: durability, stains, and curb appeal
The clearest benefit of sealing is slower water and chloride penetration, which directly reduces freeze-thaw scaling and the pitting that road salt causes on driveways. The Portland Cement Association notes that in freeze-thaw climates, moisture trapped in concrete’s pores causes scaling and cracking, and that high-quality, air-entrained concrete combined with sealing helps block both moisture and chloride from penetrating the surface.
Sealing is a secondary defence, not a replacement for good concrete. Severe freeze-thaw and deicer environments call for concrete with a suitably low water-cement ratio and proper air content within recommended ranges, and sealing works best layered on top of a slab that already meets those standards rather than as a fix for concrete poured without them.
Beyond frost protection, sealing brings a few everyday advantages:
- Oil, wine, and vehicle fluid spills wipe off more easily instead of soaking in and leaving a permanent stain.
- Efflorescence, the white chalky residue from minerals leaching through the surface, shows up less often on sealed concrete.
- Colour deepens slightly on penetrating sealers and significantly on film-forming ones, which helps stamped or coloured concrete look fresher for longer.
None of this makes concrete stain-proof or waterproof in an absolute sense. Penetrating sealers are hydrophobic but still breathable, and they don’t block every chemical or petroleum product that might hit a driveway, a point Concrete Network makes clearly when comparing sealer types. If you deal with road salt regularly, resealing every two to three years helps limit the cumulative damage that chloride exposure causes over several winters.
The real downsides of sealing concrete
Sealing isn’t risk-free, and most of the horror stories you hear about peeling or slippery driveways come from a handful of predictable mistakes rather than a flaw in the products themselves.
Slipperiness is the most common complaint, and it’s almost always tied to film-forming sealers. A high-gloss acrylic on a sloped driveway or a pool deck can turn dangerous when wet. The American Society of Concrete Contractors recommends weighing appearance benefits against function, and suggests avoiding high-gloss finishes on steep or heavily trafficked exterior surfaces unless you add a slip-resistant additive to the mix.
Peeling, hazing, and blushing usually trace back to timing. Sealing over damp concrete traps moisture beneath the coating, and as that moisture tries to escape it pushes the sealer up in cloudy patches or flakes. The same thing happens when a sealer goes down before the slab has finished curing, since the concrete is still releasing water vapour at a rate the coating can’t handle.
Sealing over spalled or cracked concrete doesn’t fix anything. A sealer bonds to the surface it’s given, and a surface that’s already flaking or cracked will keep flaking and cracking underneath the coating, often faster, because trapped moisture now has fewer places to escape. Repair comes first, sealing second, always.
- Check for existing cracks, spalling, or pitting before buying any sealer.
- Test a small, inconspicuous area and let it cure fully before committing to the whole surface.
- Avoid sealing within 48 hours of rain or when the forecast calls for rain soon after application.
Pro Tip: If you’re unsure whether your slab is dry enough to seal, tape a sheet of plastic over a small section overnight. Condensation underneath means the concrete is still too wet.
How long sealers last and what resealing actually costs
Lifespan varies a lot by sealer family, and that gap is the main thing that should drive your choice if long-term cost matters to you.
Penetrating sealers typically last three to five years or more, acrylic film-forming sealers tend to need reapplication every one to three years, and premium polyurethane or polyaspartic coatings can hold up for five to ten years or longer under normal residential traffic. A detailed breakdown of reseal cycles and the warning signs that it’s time is worth checking before you assume a sealer has failed when it might just be due.
Cost depends heavily on surface prep, repair needs, and which sealer family you choose. For a sense of what professional sealing runs in a market with real freeze-thaw exposure, typical pricing in Calgary ranges from budget options to premium professional sealing, with most homeowners paying a mid-range price for a standard double-car driveway after reasonable prep work.
- Surface prep (cleaning, degreasing, crack filling) often adds more to the bill than the sealer product itself.
- A professional bid should list the sealer brand and family, square footage, prep steps, and number of coats.
- DIY sealing can cut material costs, but mistakes in prep or timing often cost more to fix than hiring a pro the first time.
Local climate conditions also change how often resealing makes sense, since stronger UV exposure and harsher freeze-thaw cycles shorten the practical lifespan of some sealers compared to milder regions.
When to seal new concrete, and when to leave it alone
Timing matters more than most homeowners expect, and getting it wrong is the single biggest cause of sealing failures.
- Wait at least 28 days after a new pour before sealing. Concrete continues curing and releasing moisture well past the point where it looks and feels solid, and this 28 Day Rule gives the slab time to reach a stable moisture level before you trap anything underneath a coating.
- Check the weather window. Most sealers need a dry stretch of 24 to 48 hours before and after application, and temperatures within the product’s recommended range, usually above 10°C and below 32°C.
- Avoid sealing late in fall in freeze-thaw climates. A sealer applied too close to the first hard frost may not cure properly, leaving it vulnerable to peeling once winter sets in.
- Skip sealing on slabs with active structural issues. Deep cracking, heaving, or settlement needs repair or replacement, not a coating.
- Consider skipping sealing on low-traffic, low-exposure surfaces, such as a shaded interior courtyard slab that never sees salt or direct freeze-thaw cycling, where the cost may outweigh the benefit.
Spring and early summer tend to be the safest windows in most climates, since temperatures are stable and there’s usually a predictable dry stretch before fall rains return.
How to tell if your concrete is already sealed
Before you buy a sealer, it helps to know whether one is already on the surface, since applying a new coat over an incompatible existing sealer is a common cause of peeling.
- Water bead test: splash a small amount of water on the surface. If it beads up and sits on top, the concrete is sealed; if it soaks in and darkens the surface, it’s likely unsealed.
- Visual clues: a slight sheen, a darker or richer colour compared to bare concrete, or a faint plastic-like look usually point to a film-forming sealer.
- Adhesion test: a simple 30 Second Tape Test, pressing a strip of tape firmly onto the surface and pulling it off quickly, can reveal whether an existing coating is still bonded or already failing.
If the water beads unevenly in patches, or the tape pulls up flaking material, that’s a sign of partial sealer breakdown rather than a clean, intact coating. In that case, a professional moisture or adhesion test is worth the call before you commit to a full reseal, since applying new product over a failing old one usually just speeds up the peeling.
Keeping sealed and unsealed concrete looking its best
Maintenance routines diverge quite a bit depending on whether your concrete is sealed, and knowing the difference saves both money and wasted effort.
Unsealed concrete needs more frequent attention because it absorbs everything that lands on it. Spills need to be cleaned up fast, and a mild detergent with a stiff brush works better than harsh acidic cleaners that can etch the surface further. Sealed concrete, by contrast, mostly needs a rinse and an occasional mop, since most spills sit on the surface rather than soaking in.
- Sweep or rinse unsealed concrete weekly in high-use areas to prevent dirt from grinding into the pores.
- Clean sealed concrete with plain water or a pH-neutral cleaner; avoid solvents that can dissolve film-forming coatings.
- Avoid rock salt on unsealed concrete whenever possible, since chloride ions are a major driver of surface scaling; switching to a calcium-based de-icer or removing salt residue promptly limits the damage.
- Reseal penetrating coatings on a three-to-five-year check cycle, and inspect film-forming coatings yearly for wear in high-traffic zones.
Pro Tip: Keep a small logbook of when you last sealed your driveway. It’s an easy detail to forget, and knowing the exact date makes it much simpler to judge whether wear is normal or a sign the sealer failed early.
Routine maintenance also means catching small problems before they become expensive ones. Regular cleaning, prompt spill removal, and proper jointing maximize the service life of both sealed and unsealed concrete, which matters whether or not a coating is involved.
Field tips for getting sealing right the first time
A lot of sealing failures come down to skipping a basic check, not a bad product. Two simple field tests catch most of the common mistakes before they become expensive.
- The 30 Second Tape Test works on existing sealers too: press tape firmly, pull quickly, and if coating flakes off with it, that surface needs stripping before any recoat.
- The 28 Day Rule for new pours isn’t a suggestion, it’s the minimum window most sealer manufacturers specify for curing before the surface can accept a coating properly.
- Temperature matters as much as the calendar date. A dry, mild stretch in spring or early fall gives a sealer the best chance to cure evenly before rain or frost returns.
- Professional crews typically bundle cleaning, minor crack filling, and exterior repair contractor hiring tips that save you money into one visit, since prep quality affects how long the sealer actually lasts more than the product choice itself.
Homeowners who try to shortcut prep, by sealing over a dusty or damp driveway, or skipping a small test patch, tend to be the ones calling back a year later asking why the coating is peeling. A short inspection before the sealer goes down catches almost all of that in advance.
Our take on choosing a sealer
For most driveways and walkways, we lean toward penetrating sealers because they protect against the damage that actually matters, water and salt intrusion, without turning a walking surface into a hazard. Film-forming sealers have their place on decorative patios and stamped concrete where colour and gloss are part of the point, but that choice should be made deliberately, with eyes open about the slip trade-off and shorter reseal cycle.
The habit we’d push hardest isn’t about which product to buy. It’s inspect first, repair first, test first. A sealer applied to a clean, dry, structurally sound slab will outperform a more expensive product applied in a hurry, every time.
— Lewie
Professional concrete cleaning and sealing from YearLong
If reading through cure times, tape tests, and sealer families sounds like more than you want to manage on a weekend, booking a professional visit handles all of it in one trip. Professionals inspect the slab, pressure wash and degrease the surface, fill minor cracks, and pick a sealer suited to the concrete’s finish and exposure before applying it correctly the first time.
Our concrete sealing service covers the full process from cleaning through application, and it pairs naturally with our concrete cleaning service if your driveway needs a deeper wash before sealing makes sense. A quote typically reflects square footage, current surface condition, and sealer type, the same cost drivers that apply anywhere.
- Inspection and moisture check before any product goes down.
- Pressure washing and degreasing to remove oil, dirt, and residue.
- Minor crack filling and surface prep included in the visit.
- Sealer matched to your concrete’s finish, whether broom, stamped, or exposed aggregate.
If you’re weighing a sealing job against other exterior upkeep this season, our concrete sealing page has details on what a visit includes and how to request a quote for your driveway or walkway.
FAQ
Can I mop unsealed concrete?
Yes, mopping unsealed concrete is fine, though plain water or a mild, pH-neutral cleaner works better than harsh acidic products that can etch the porous surface. Dry the area afterward when possible, since unsealed concrete absorbs moisture more readily than sealed surfaces.
Can you seal concrete that has already been sealed?
Yes, but only if the existing sealer is still well-bonded and compatible with the new product, which you can check with a simple adhesion test like pressing and pulling tape on the surface. If the old coating flakes off during that test, it needs to be stripped before resealing, since layering new sealer over a failing one usually leads to peeling.
How can I tell if my concrete is sealed or not?
Splash water on the surface: if it beads up rather than soaking in, the concrete is sealed. A slight sheen or darker colour compared to raw concrete is another common visual clue that a sealer is present.
What is the downside of sealing concrete?
The main downsides are increased slipperiness with glossy film-forming sealers and the risk of peeling or hazing if the sealer is applied over damp or uncured concrete. Sealing also does nothing for slabs that already have structural cracking or spalling, since those need repair first.
Sources
- Cement
- Concrete Network — Penetrating concrete sealers
- NAHB guidance on silane and siloxane water repellents