5 Important Reasons to Seal Broom Finish Concrete Driveway
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Do You Seal Broom Finish Concrete Driveway?
Yes you must seal broom finish concrete driveway. Spray a high quality penetrating sealer once the concrete has fully cured (typically 28 days). Reseal every 7 – 10 years or earlier if required.
Concrete slabs need to be sealed, irrespective of the concrete finish. For all its strength, concrete is a porous material. If not sealed, rainwater and snowmelt will soak into the pores.
Water ingress into the concrete pores is extremely damaging in the long run.
“The most destructive agent of concrete structures and components is probably water”.
Quote from Wikipedia
If you do not keep your concrete driveway sealed at all times, its strength & durability will be seriously compromised.
What Happens If You Do Not Seal Broom Finish Concrete Driveway?
If you do not seal broom finish concrete driveway then its strength & durability will be compromised.
Water damages broom finish concrete driveways in 3 ways:
- Acidic Chemical Corrosion: Rain and groundwater has acidic chemicals that corrodes both the aggregates and the steel reinforcement.
- Alkali Silica Reaction (ASR): Water also contains alkaline chemicals. Alkalis react with silica in the aggregates to form a hygroscopic gel. The gel expands, stressing the aggregates and even cracking them.
- Freeze Thaw Cycle: Water within the concrete pores freezes when temperatures fall and thaws when temperatures rise. This cyclical stress can ultimately lead to structural failure.
A sealer protects concrete from the damaging effects of UV radiation, as well. Polymer and other bond chains make concrete strong and long lasting. However, long exposure to harsh sunlight breaks down these bonds over time.
UV radiation weakens the concrete, turning the top layer into fine dust. Broom finish concrete will start to lose its roughness and skid resistance. Cracking and spalling may also occur.
Car tires are abrasive as they have dirt & grit on their surface. A bit like sandpaper. Car tires can wear down the ridges of the broom finish concrete driveway pretty fast. The skid resistance of the broom finish concrete decreases with prolonged exposure to vehicular traffic.
Topical sealers adhere to the broom finish concrete surface and form a fine film. The sealer coat acts as a buffer between the tire and concrete. The sealer protects the concrete from abrasion.
The strength & life of a broom finish concrete driveway is enhanced by sealing it and resealing it regularly.
When Should You Seal Broom Finish Concrete?
So, what is the best time to seal a broom finish concrete driveway? Seal it once the concrete has fully cured, typically 28 days after the pour. This is the initial sealing. Thereafter, you need to reseal as and when the existing topical sealer loses its efficacy.
Initial Sealing
After concrete has been poured for the driveway you need to wait for 28 days for full curing before applying sealer coats for the first time.
Sealers, both penetrating and topical, will interfere with the curing process by trapping water. So never apply sealers before the concrete has fully cured.
However, you should not wait too long to apply the sealer, after the concrete has fully cured. Delay in applying the sealer, after full concrete curing, exposes the broom finish concrete driveway to the possibility of moisture & water penetration.
This moisture will get trapped inside the concrete, once sealer is applied. You want to keep trapped moisture as low as possible.
Resealing
Both Penetrating & Topical Concrete Sealers have a lifespan. They get depleted from natural wear & tear. Sealers will lose their ability to protect the concrete over a period of time. Concrete slabs therefore need to be resealed periodically.
Penetrating Concrete Driveway Sealers last 7 – 10 years. Acrylic Topical Concrete Driveway Sealers last 1 – 3 years. Epoxy or Polyurethane (PU) Topical Concrete Driveway Sealers last 5 – 10 years.
There is a very simple test to find out whether the existing sealer is still effective or not. Wipe the sealed concrete surface with a damp rag to remove dust. Place a few drops of water on the surface.
If the water beads up the way it would on a sheet of glass or a lotus leaf, then the sealer is still effective. Do not reseal the concrete driveway.
If the water does not bead up and flattens out or gets absorbed by the concrete, then the existing sealer is no longer effective. It is time to reseal the concrete driveway.
Based on my experience, you should reseal your broom finish concrete driveway every fall, with just one coat of topical sealer. This will protect your concrete driveway from the winter snow and rain.
Do not overdo the topical sealer as a thicker film will fill up the valleys in the broom finish texture. This will make the driveway slippery.
Does Sealer Make Broom Finish Concrete Slippery?
A penetrating concrete sealer does not make broom finish concrete slippery. Why? Because it does not form a film. A Penetrating Concrete Sealer penetrates into the capillaries of the porous concrete slab, reacts with the free lime & calcium and blocks the pores from within.
A topical concrete sealer, on the other hand, does make the broom finish concrete slippery. Not only does it form a film, it also forms a thicker film in the valleys and a thinner film on the ridges of the broom finish grooves.
Topical sealer is still required to protect the concrete from UV radiation and abrasion. But it is not critical.
You should minimize the use of topical sealer on broom finish concrete and rely more on the penetrating sealer for protection from moisture & water ingress.
What Is the Best Sealer for Broom Finish Concrete?
A silane / siloxane water repellent penetrating concrete sealer is the best sealer for broom finish concrete.
A penetrating concrete sealer penetrates into the concrete pores and chemically reacts with compounds in Portland Cement to form a hydrophobic barrier.
Penetrating sealers repel water, moisture, salts, chemicals, dirt, etc. so that they can not find their way into the concrete pores. As a result they protect the broom finish concrete driveway, not only from corrosion & degradation, but also from mold, mildew, fungus, freeze thaw and efflorescence.
Occasionally a fine coat of UV resistant topical sealer can also be applied on the broom finish concrete. It will protect the concrete from abrasion and polymer breakdown.
RECOMMENDED PRODUCTS
The Best Sealers for Your Concrete Driveway or Patio
A topical sealer is essential for protecting concrete surfaces from water permeation that can damage the concrete from within and compromise its lifespan.
I highly recommend Foundation Armor Concrete Sealers. Pick the one that best meets your aesthetic and application preference.
Thank you very much for reading this post. I do hope you found it informative and helpful.
