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One primary objective for many home owners is to seal the concrete of their garage floor in order to protect it from water intrusion, dusting, road salts, pitting, and most importantly, to help resist oil stains. If you want to do this at the best value and without concern about having the latest decorative finish or coating for your garage floor, then a siliconate penetrating concrete sealer may be all that you need.
Why? Although decorative garage floor coatings such as epoxy look great and do a good job of sealing the concrete, there are people who have simple “working” garages. They are not as concerned about how nice a concrete sealer looks, but rather how well it performs without a lot of expense and preparation. If you think this may be you, then here is why you need to consider a siliconate concrete sealer.
What makes a siliconate sealer different than a coating is the fact that it actually penetrates (hence the name) into the concrete floor to create a protective barrier at the sub surface. Other garage floor sealers such as acrylic, epoxy, and polyurethanes are topical in nature. They sit on top of the surface to form a protective film or coating.
Once applied, a siliconate sealer works by permeating into the pores of the concrete and chemically reacting with carbon dioxide. This reaction creates a cross-linking molecular membrane barrier that almost gel-like and hydrophobic in nature.
This hydrophobic barrier is effective at repelling water and other liquids such as chemicals, salts, and oil. In essence, water, automotive fluids, and most other liquids will tend to bead or sheet on the concrete instead.
How a siliconate penetrating sealer works on a concrete garage floor
Furthermore, the chemical reaction that fills the pores and capillaries within the upper surface of the slab has the additional benefit of slightly strengthening the surface of the concrete as well. While not as effective as a densifier for surface strength, it does help with surface wear none the less.
Concrete Siliconate Sealer Benefits
- Forms a hydrophobic barrier to help prevent intrusion of water and other liquids
- Reduces staining including oil, gas, and other automotive fluids
- Helps to prevent pitting, spalling, and surface cracks from water absorption
- Reduces concrete dusting and helps prevent efflorescence
- Helps to prevent the harmful effects of road salts and deicing fluids
- Inhibits mold and mildew growth
- Breathable, water based and low in VOC’s
- Excellent for garage floors, driveways, walkways, patios, and basement floors
- Low cost delivers one of the best values in concrete sealers
As stated, additional benefits to consider include mold and mildew resistance as well as protection from the harmful effects of road salts and deicing fluids. This means that if your garage temperatures drop below freezing overnight, the surface will be protected from the pitting and spalling that can occur due to the expanding effects of freeze thaw cycles from melted snow and deicing fluids that can seep into the concrete.
Siliconate sealers dry to a natural looking finish without any sheen. And because a penetrating sealer is non film forming, it allows for the same anti-slip protection as bare concrete.
Furthermore, you don’t have to worry about damaging the sealer if you drag sharp objects across the garage floor when working on cars or projects. They are also a favorite concrete sealer for driveways, walkways, and patios.
Other factors to consider are expense and ease of application. This is what makes a siliconate concrete sealer for your garage floor one of the best values you can find.
Most 2-car garages will require only one or two gallons of sealer depending on the manufacturer. Cost is usually less than $50 a gallon for a quality product and application is much easier than applying a coating or even paint for that matter. Expect it to last up to 10 years or more before a new application is necessary.
One thing to be aware of is that concrete penetrating sealers do not seal cracks. Cracks will still need to be repaired first in order to seal the garage floor properly.
Best Siliconate sealers that we recommend
There are two products we like to recommend that work extremely well and get great reviews.
The first is PS101 by Concrete Sealers USA
. This siliconate sealer has a strong reputation for great performance and is known for lasting years. In fact, the reviews are outstanding.
It only wears down as the concrete wears down and can also be used as a “cure and seal” for new concrete. Application is easy with no special mixing required. The coverage rate is 300 – 450 ft² per gallon for machine troweled and smooth finishes.
Purchase PS101 Concrete Sealer – 1 Gallon
Purchase PS101 Concrete Sealer – 5 Gallons
Important to note; if you plan on using a siliconate sealer for a broom finished garage, Concrete Sealers USA recommends their PS102 Multi Surface-Concrete Sealer.
PS102 also works extremely well for driveways, walkways, and patios. The reason for this is that these type of finishes are typically more porous that a steel troweled or machine troweled garage floor. PS102 is formulated for the more porous surface that these finishes provide.
Purchase PS102 Multi-Surface Concrete Sealer
Expect a coverage rate of 200-300ft² per gallon for these type of applications. Just as the PS101, it can be also be used as a “cure and seal” for newly poured concrete.
The second product we can recommend is Armor SC25 by Fountation Armor. Besides garage floors, this penetrating siliconate sealer is developing a strong reputation for use on driveways, walkways, patios, and basements.
The coverage rate is 200 – 250 ft² for machine troweled or smooth dense surfaces and 100 – 150 ft² for a broom finish or rough surface.
Just as the PS101, SC25 is water based and no special mixing is required. One note to make is that Foundation Armor does not recommend SC25 as a “cure and seal” for freshly poured concrete.
Purchase SC25 here from Amazon
One thing to pay close attention to is the spelling for penetrating sealers. For instance, a popular seller at home improvement centers is silicone sealers. Notice the difference? Silicone versus siliconate. It’s easy to miss this.
We do not recommend a silicone sealer for a garage floor or outside on walkways, driveways, and patios. The reason is that they tend to sit more on top of the surface and do not penetrate as well.
Though they have good hydrophobic and oileophobic properties, they wear down at the surface extremely quick and lose their sealing properties. Yearly reapplication is recommended. They also are not U.V. resistant and will deteriorate over time when exposed to sunlight.
Will a siliconate sealer stop oil stains in concrete?
This is one point that we want to make clear. Though siliconate concrete sealers can be fairly resistant to oil stains, they are not stain proof. In fact, there is not a penetrating sealer available that is. Only a commercial quality garage floor coating will provide close to stain proof oil protection.
The reason for this is that penetrating sealers are non-film forming. Unlike coatings, they seal the concrete at the subsurface. However, what makes a siliconate sealer unique is that they consist of a relatively larger molecular structure than many other types of penetrating sealers. This allows for better surface protection and better resistance to oil stains.
The best protection from oil stains when using a penetrating sealer is to clean them up as soon as you see them. Don’t let them dwell or sit for a long time. If they do sit, they will eventually seep into the very upper layer of the concrete surface and can leave a faint stain once cleaned.
If resisting oil stains are your primary concern with a penetrating sealer, then we suggest you read our review of PS100 Oil & Salt Repelling Sealer by Concrete Sealers USA.
In addition, GhostShield has a combination system for oil repellency that uses penetrating sealers as well. You can read our review of GhostShield 8510 and learn how this system works.
Applying a penetrating sealer to your garage floor
Make sure the surface of the garage floor is free of dust and oil. Clean up any oil spills that may have accumulated and scrub the surface of your garage floor with TSP and a stiff bristled brush. A floor maintainer with a black pad works even better.
Rinse off the surface with a hose and let it thoroughly dry – usually 24 hours is sufficient unless the humidity is up. When ready, apply the sealer with a low pressure pump sprayer or roller and paint brush. Do not let it puddle till dry or it will leave a white chalky substance that is hard to remove. The area should be ready for traffic in 12 hours. That’s it!
Once done, you will have a natural looking surface that is protected for the next 10 years or more depending on traffic. So if you are the no frills, “working” garage type of person that wants to protect their garage floor with minimal preparation and expense, then a siliconate penetrating garage floor sealer is definitely worthy of your consideration.
can an acrylic sealer be applied on top of penetrating sealer? I’m interested in the best of all worlds for my garage floor treatment, and wonder if this could work and how would I make a successful application of this combo?
Hi Adam. In most cases, an acrylic sealer can be applied to concrete that has been treated with a siliconate sealer. Always check with the vendor or manufacturer first though before application. However, this is not true of resinous coating such as epoxy. The sealer would need to be removed via grinding first. As an FYI, many acrylic sealers do not perform well for a garage floor. Use a solvent-based acrylic at the minimum, not a water-based. The best type of acrylic to use is an MMA acrylic sealer. This is an example here.
I have a new basement that was dug out and the concrete floor is producing a lot of dust that is being tracked through the house. Is one of these products a good choice to take care of the dusting issue? The space is used for storage, no vehicles parked on it, shovels dragged over, etc. Thanks
Hi Bert. No, PS101 or any other siliconate sealer on it’s own is not enough to stop a lot of dusting. We have an article here that discusses dusting and what type of products can be used.
Do you need to etch the floor to prep before applying a penetrating sealer?
Hi Cathy. No, etching is not usually required unless the concrete is extremely smooth. To test, place a few drops of water on the concrete in various areas. If the concrete turns darker and absorbs the water within a few minutes, then you can use a penetrating sealer.
I have densified my shop slab with Dayton Pentra-Hard, a lithium-based densifier. The slab has a steel trowel finish. What are my options for a sealer? I want to prevent staining and allow ease of cleaning for general automotive use/repair.
I don’t love the idea of a topical sealer that will wear off quickly.
Hi Chris. Though there are commercial quality topical coatings designed to last years, however, the densifier treatment precludes the use of them unless you were to grind the concrete. This leaves you with using a penetrating sealer, providing that the current surface will still absorb enough water in order to accept them. Penetrating sealers can help to resist stains, but they are not stain proof since they are non film forming. We can recommend a couple of sealers. The first would be PS100 by Concrete Sealers USA. It’s an oil resistant sealer that works very well. The other would be GhostShield 8510. It’s an oil resistant sealer as well. You will need to do some water drop tests in various areas first to make sure that the concrete will accept them. If the surface immediately turns a darker color and will absorb a few drops of water within a minute or so, then you will be OK. However, if the water tends to sit there for a long period first, then you may need to sand the surface (not grind) first to knock down the hydrophobic effect of the newly applied densifier.
Thanks! I really appreciate the reply. That is also what my research led me to, so good to have you confirm it.
Can I use a stain (before or after) with a siliconate penetrating sealer? I have a cabin with a slab we poured a few months ago. I don’t care a whole lot about the look so much as the expense, ease, and maintenance. But right now it looks pretty white and I’m wanting a slightly darker color.
Hi Dylan. Stains can only be applied to bare, untreated concrete. If any type of sealer is applied first, the stain will not take. To answer your questions, yes, a sealer such as this can be applied after the stain. However, most stains have a clear coating applied over them in order to protect the surface and to make the color pop. Penetrating sealers such as PS101 will not do that. The concrete will retain the same matte / dull color. Something else to consider is that true stains will not provide a solid looking color. They will be mottled and varying in color as they react with the concrete surface and density. This article about Delta Dye will give you a better idea.
We just finished building a garage with a concrete floor that was poured 4 months ago. I have a few questions. 1) The concrete guys spilled a plate sized section of concrete that’s at least 1/8″ deep that will need ground down to match the rest of the floor. (I’m not calling them to fix it because I don’t want to see them ever again.) What kind of tool/angle grinder/drill bit attachment do you recommend to grind this down and also get it to a smooth surface in order to seal it? 2) As it’s brand new, do I need to do a thorough TSP cleaning of the floor? The only thing on the floor is a some drywall dust and mud from boots. 3) I think we are going to apply a penetrating sealer with either a sprayer or mop. Should I also seal the 4″ knee wall? Which sealer do you recommend for a brand new floor?
Hi Joy. I’m assuming that the plate sized concrete that was spilled on the surface was done after it was troweled or it wouldn’t be there. If that is the case, we recommend taking a hammer and large chisel to it first. Hold the chisel at an angle that is almost parallel to the floor, but not quite. Many times concrete that is spilled onto a troweled surface will not adhere very well and can actually be knocked off this way. If that doesn’t work, then you will need to grind. We recommend using a 4″ or 7″ angle grinder with appropriate sized concrete turbo cup grinding wheel. This will make quick work of it. Just make sure to were a respirator as the concrete dust will be impressive.
Before applying a sealer, clean the surface with a mild scrubbing using a deck brush and a soapy solution or concrete degreaser. Rinse well. You don’t need something as aggressive as TSP. Once it has thoroughly dried, you can apply a sealer. We would recommend using PS101 siliconate sealer or PS104 densifier with siliconate sealer added. Either one with do a great job. If you are in snow country and the floor will see some deicing fluids or road salts, then use the PS104. It won’t hurt to do the stem walls if you have additional sealer remaining.