Concrete Repair Plus

Concrete 101

White Stains on Concrete: Efflorescence in Toronto

The white haze is not mould and not paint failure. It is your concrete telling you where the water is.

June 3, 2026 · 4 min read

The short answer

The white staining on your concrete, some people describe it as a white fur or fuzz growing from the floor, is efflorescence: water moving through the slab dissolves salts, carries them to the surface and evaporates, leaving the minerals behind. It is cosmetic, but it is also a moisture report, persistent efflorescence means water is moving through the concrete and is worth investigating before coating or sealing anything over it.

A weathered porch floor with pale mineral deposits and rust staining across the surface
Pale deposits on the surface are salts the concrete carried out with it. The deposit is the symptom, the moisture path is the problem.

What efflorescence is

Efflorescence is the chalky white deposit that appears on concrete, brick and parging, when it crystallizes it can even look like a white fur or fuzz growing out of a basement floor. It forms when water moves through the material, dissolves soluble salts inside, and carries them to the surface, where the water evaporates and leaves the salt behind. It is cosmetic in itself, but it is a reliable sign that water is moving through the concrete.

Why it matters

The deposit is harmless, but the moisture behind it is not. The same water travel that leaves efflorescence also feeds freeze-thaw damage and, over time, corrosion. Persistent efflorescence on a foundation wall, a slab or parging is worth tracing to its source (grading, a downspout, or moisture from below) rather than just wiping off.

How to deal with it

Light efflorescence often brushes off dry or rinses away; heavier deposits may need a proper efflorescence cleaner. But cleaning treats the symptom. The lasting fix is addressing the water: correct the grading or downspout, repair cracks letting water in, and seal the surface so moisture stops migrating through. On a coating or paint job, dealing with efflorescence and moisture first is what stops the finish from failing later.

Key takeaways

  • Efflorescence is mineral salt left behind by water moving through concrete.
  • The deposit is cosmetic; the moisture behind it is the real signal.
  • Cleaning removes it; fixing drainage and sealing keeps it from returning.
  • Recurring efflorescence is worth tracing to a water source.

Frequently asked

Is efflorescence the same as mould?

No. Efflorescence is a mineral salt deposit and brushes off as powder; mould is biological. If white deposits keep returning, the issue is water movement, not mould.

Will sealing stop it?

Sealing helps by reducing water migration, but only after the water source is addressed, sealing over an active moisture problem can trap it.

Reviews

Five stars, in their words.

Google Reviews

Real reviews from our Google Business Profile, verbatim, verifiable.

David

3 reviews

TodayNew

Huge shout out to this company. Our concrete porch was showing significant wear and tear and we wanted to take action before a total rebuild would have been required. The team at Concrete Repair Plus was extremely patient, came to the house several times to provide a quote and share Graniflex samples, did fantastic work and (bonus) actually refused payment until every last touch up was complete on our newly finished porch (which looks amazing, BTW). We had spoken to other repair companies but did not love that they used "in-house" epoxy porch repair coatings for which we could not find industry info / reviews. Very happy we chose Concrete Repair Plus to refinish our porch with the Graniflex system, a well-known and very well reviewed product. Thank you!

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Jodi Leigh

6 reviews

4 days agoNew

We redid our porch and the process was seemless from asking for a quote, to scheduling the work, and then the work itself. The workers were friendly and knowledgeable so made the whole process easy for us. Reasonably priced compared to others we compared to and very happy with the final product. Would use them again!

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James B

Local Guide · 25 reviews · 20 photos

2 weeks agoNew

Our experience with Concrete Repair Plus was nothing short of exceptional. The crew was extremely professional, on-time and neat. Finished product was above expectations. Crew was knowledgeable and kept us informed all the way through the process. Equipment used was best-in-class. We would strongly recommend Concrete Repair Plus to anyone thinking about replacing their garage slab or interested in doing concrete repairs. Pricing was competitive. We would use them again.

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Natalie F

Local Guide · 27 reviews · 6 photos

A week agoNew

Needed to repair a concrete porch and steps in Vaughan for a detached home, they did a fantastic job prepping and repairing then using the graniflex system. from quote to scheduling everything was easy! All the neighbours were coming over to check it out and say it looks fantastic. Definitely elevated and refreshed the homes curb appeal.

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Daniel Marinelli

2 reviews · 7 photos

2 weeks agoNew

I contacted Concrete Repair Plus a few weeks ago to tear-out and repour a concrete porch and steps leading up to the front of my house in North York. I contacted them after having an awful experience with a previous concrete contractor who took my deposit and strung me around for over a month, never to return. The level of care and respect I received from Concrete Repair Plus was incredible. After explaining the situation I was in, they sent me Nick and his crew (Jeremy and Milton) and told me I would be in good hands; they were absolutely right. Nick was so respectful; always taking the time to ensure he messaged me exactly when he was coming and what he'd be doing. He had a vision for how this job would look and made sure to include me in the planning of it come time for the formwork. Watching Nick work with Milton and Jeremy was really something. They paid attention to small details: perfect corners on the steps, a gentle slope to drain water away from the house, the first step that meets the driveway was deep enough to be paved around properly, the really nice full broom finish. The form work was done so meticulously, ensuring that the final product would be perfect. Milton and Jeremy always cleaned up at the end of every day, leaving the site looking better than when they arrived. And they were just such nice guys too. What more could I ask for? It's now been a couple of weeks since the job was finished and it looks fantastic. I couldn't be happier with the result! I'm looking forward to contacting them again for any future projects.

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Glen Johnstone

Local Guide · 13 reviews · 3 photos

Edited 2 days agoNew

Excellent experience with Concrete Repair Plus! They removed the old concrete jewel stone finish from our porch and applied a Graniflex System, and the results look fantastic. The crew was professional, efficient, and paid great attention to detail. They took great care to remove and reinstall the existing railing, protect the surrounding property, and cleaned everything up when the job was finished. I highly recommend Concrete Repair Plus and will definitely call on them again - Scarborough, ON

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Clive A

9 reviews · 7 photos

a month ago

I recently had Concrete Repair Plus at my residence in Whitby to remove and replace the 66 year old garage floor. It was explained to me that it was not a good idea to grind and epoxy the floor but complete replacement was the way to go. The price was reasonable and the advice was excellent. Staff were on site had the floor removed and repoured the same day. The driveway was covered to prevent concrete spills/splashes. Saw cuts were completed next day. We are now in the process of covering the walls to clean it up. Definitely a five out of five and I would recommend you reach out for a quotation.

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Richard Fawcett

7 reviews

2 weeks agoNew

We have owned our home for over 40 years and needed to change the garage floor. Last week Concrete Repair Plus removed the old garage floor and replaced it with a new one. The work was done in 2 days. Their team was professional and courteous, and the price was reasonable. We give them 5 stars. R. Fawcett Mississauga July 2026

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Johnny

4 reviews

a month ago

I had these guys out to my property in Bowmanville to do a complete garage floor replacement, and boy am I glad I did. They did an excellent job on the entire project and after one little hiccup they went WELL above and beyond to make sure I was satisfied with the final product. My polished concrete floor looks amazing. Never realized how much better polished concrete can look versus epoxy. I wouldn't hesitate to use Concrete Repair Plus if I ever have another concrete project again

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