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For many home owners a primary concern is to seal the concrete of their garage floor in order to protect it from water intrusion, dusting, road salts, pitting, and most important, 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.
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 is hydrophobic. This barrier is effective at repelling water and other liquids such as chemicals, salts, and oil. It’s this barrier that helps prevent liquids from transferring through the surface. In essence, water, automotive fluids, and most other liquids will tend to bead or sheet 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 also tends to strengthen 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 penetrating sealers for concrete do not seal cracks. Cracks will still need to be repaired first in order to seal the garage floor properly.
Will a siliconate sealer stop oil stains in concrete?
There 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 most other penetrating sealers. This allows for better surface protection and better resistance to oil stains than most other concrete sealers.
For the best protection from oil stains when using a penetrating sealer, it’s important to clean them up as you see them and not 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 possibly leave a faint stain once cleaned.
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
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 here from Amazon
After speaking with a representative from Concrete Sealers USA, they recommend their PS102 if you have a broom finished garage floor. It’s formulated for the more porous surface that a broom finish provides.
PS102 also works extremely well for driveways, walkways, and patios since these are typically a more porous finish as well. 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.
Purchase PS102 here from Amazon
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.
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.
I’ve read much of the information on your terrific website and many of the q/a, but I want to make sure I’m moving the right direction. I have a moisture problem in my garage when the humidity is high. The floor has damp areas and some crystalizing. I arranged for a quote to have a dealer epoxy the floor and he said that I wouldn’t be happy with the results. I’ve been interested in your comments about penetrating garage floor sealers and want to make sure that this process should eliminate my moisture problem? And that I can then put a topical floor paint over this? Maybe even epoxy? Thanks.
Hello Ron. Applying a penetrating sealer is never a guarantee that your moisture problem will be solved. Was it determined that the moisture was coming from up under the slab and not condensing on the surface during high humidity? Was a moisture test conducted? If so, how many pounds per 1000 sq. ft. was it? There are moisture blocking epoxy primers that work quite well, depending on the moisture content, that professional installers should know about and discuss as an option. Was this done?
Where can I get this concrete sealer and what is a good brand or name of it.
Hello Norine. Here is the link for both PS101 and SC25. Both are great products.
Shea, how would you decide whether to go with one of these 2 vs the GhostShield products?
What it comes down to in many cases Chris is cost over function. A good siliconate sealer is one of the best values for sealing and protecting your concrete from typical use. If you just park your cars in the garage and maybe do the occasional oil change, then a siliconate will get the job done just nicely. However, if you are one to use your garage more for various projects, automotive repairs, and where you may be encountering oil spills and other chemical mishaps, then the GhostShield products would be the better choice, albeit more expensive.
Shea –
I have a smooth concrete floor in my former garage, now a recreation room with a pool table, ping pong table, foosball table and dart board. I want to cover the floor with a commercial carpet, attached by glue. I noticed that when the humidity has been high, on occasion there have been dark spots on the floor, which I believe were condensed moisture rather than water coming up from below. No standing water. What kind of sealer, and which brand name, would you recommend for me — DIY — to use before I have the professionals glue the carpet? I definitely do not want to grind the floor or use acid to rough it to 120 grit, as some floor sealers require before applying the sealer. If you don’t know the answer, can you refer me to someone who might? Thank you.
Hello Peter. If you are getting condensation on the floor from humidity, a sealer is not going to stop that. The water forms on the surface when relatively warm moist air comes in contact with the relatively cooler concrete and condenses. The carpet will prevent that from happening. You can do a simple plastic sheet test to verity. Tape down on all four sides a 16″ square sheet of plastic where you get the dark spots. If the sheet has water underneath, then you are getting moisture up from under the slab. If the plastic sheet is dry underneath but wet around the outside, then it’s simple condensation. If you want to seal it anyway, contact Concrete Sealers USA. They have a Silane sealer, PS105, which should work fine for what you want to do.
Thanks for all the information. I’ve learned so much about concrete sealers. Based on all your information I am planning on using a siliconate sealer on my garage and driveway. Is there a difference between TL39 Concrete Densifier & Waterproofer and the PS101 and V-Seal 101? The tech data sheet for the TL39 states that its a water based siliconate and lithium densifier & waterproofer.
Thank You.
Hello Leo. The TL39 is a concrete densifier first and concrete sealer second. For the best sealing we would recommend the the PS101 or V-Seal 101 – especially for the driveway. If your driveway is especially porous, Concrete Sealers USA carries PS102 which is a silicontate sealer for more porous concrete. If you are unsure, we recommend giving Concrete Sealers USA a call and talk to them. Their customer service is excellent. They actually try and call each customer that orders their product, whether it’s from their own site or Amazon, to verify that they made the right choice based on their concrete sealing needs.
I will like to order floor sealers. Available in 5 gal. pail. Meet ASTM D-2047 requirement for slip resistance.
Hello Edward. We recommend contacting either Concrete Sealers USA or Foundation Armor to find a sealer that will meet your specs.
Shea – Terrific website, exactly what I was hoping to find when starting my garage floor project. Thank you. After reading through some of your articles and the related comments I think I understand what I need to do but just wanted to confirm. I have an approximately two year old, three-car garage floor with some light spalling in a couple places and no moisture issues (at least that I am aware of). My primary concern is protecting the garage floor from further spalling and potential pitting/cracking. I am in the Midwest so get plenty of snow/salt. It seems like the siliconate-penetrating-sealer is the way to go.
1. Do I need to repair the light spalling (is it worth the effort?) before applying the siliconate-penetrating-sealer? I do not think I have any pitting or cracks but if I do, same question.
2. If I need/should do any repairs prior to applying the siliconate-penetrating-sealer I was planning on using the Rust-Oleum EpoxyShield Concrete Resurfacer and then use PS101 penetrating sealer, but it sounds like there could be some issue due to the resins. Best to just contact Concrete Sealers USA regarding best repair product to use prior to applying the PS101?
3. No need to grind floor prior to PS101 application if there is no paint/apoxy/previous sealant/etc., right? And should also just be good with one application?
4. Finally (sorry for long comment), if I want to dress up the floor a little after applying the PS101 with an apoxy/paint/etc., I will need to grind the floor first, correct? Also, will the application of the PS101 improve the lifespan/performance of the apoxy/paint/etc.?
Thanks for your advice!
Hello Andy, you are correct on most counts. There is no need to repair the light spalling if it does not bother you. If you have any questions about product compatibility or product in general, just call and ask for Mike at Concrete Sealers USA. He’s a nice guy and likes to help people out. If you decide at a later date that you want to apply a coating to the floor, you will have to grind the surface. Etching will not work. Prior application of a siliconate sealer to the concrete before application of a coating will not improve the performance of the coating.
In your previous reply, you state that if you decide at a later date that you want to apply a coating to the floor after using a penetrating sealer like PS101, you will have to grind the surface and that prior application of a siliconate sealer to the concrete before application of a coating will not improve the performance of the coating. However, Concrete Sealers USA’s FAQ page states otherwise:
Can topical concrete sealers (ex. acrylics, epoxies, urethanes, etc.) be applied over penetrating sealers?
Yes, topical sealers generally can be applied over most penetrating sealers. Penetrating sealers generally do not form a membrane, film, or barrier that would prevent the topical sealers from adhering to the surface. As a matter of fact, most penetrating sealers were originally developed for use as primers to be applied prior to topical coatings and sealers being applied.
Yes, that would be the case if you wanted to apply an acrylic sealer or paint for example. Also note that the coating is being applied on the surface. Epoxy and other resinous coating still require that the surface be profiled correctly to achieve a mechanical bond. A penetrating sealer does not eliminate the need to profile the concrete. Profiling the surface generally involves an acid etch or mechanical means such as grinding or shot blasting. Since a penetrating sealer would effectively block the acid etch from accessing the free lime in the concrete, it would just sit there and not work. That is why you need to grind or profile by mechanical means if epoxy will be applied.
Thanks for your quick response!
I plan to eventually paint the surface with Rust Bullet garage floor paint. Since this will be applied to the surface, are you saying it would not be necessary to profile the surface with this specific product?
Thanks again!
Marc
Rust Bullet states that if a sealer was applied to the concrete then it will need to be removed or properly profiled first Marc. However, since you are dealing with a penetrating sealer, we recommend requesting a sample first to test on the concrete in a few areas. Garage Flooring LLC or Rust-Bullet can advise you on the testing procedure (it’s not difficult).
I want to paint my new concrete garage floor but it has already been sealed with PS 101 Siliconate Multisurface WB Penetrating Sealer. Will oil based Porch and Floor Enamel be compatible with the sealer?
More than likely no, Holly. Paint generally does not adhere well to sealed concrete. If you want to paint it you may need to grind the surface first. We recommend contacting Concrete Sealers USA to verify.
I am concerned with damaging grass next to driveway and sidewalk with these products since both products mentioned are not “eco-friendly” and may damage vegetation. I’m considering rolling on but i’d like the easier application of a sprayer. Can you recommend a good long-lasting eco-friendly siliconate sealer or a method of application that prevents overspray onto grass?
Hello Drew. You are just applying it with a garden type pump up sprayer, not a commercial high pressure paint sprayer. There is no fog or mist of the product to worry about. The cone type spray head is what you want to use, not the fan spray head. It’s very easy to control. You can roll it on if you choose, but the coverage rate is not as high. Unfortunately, “eco friendly” and “long lasting” do not work together with quality sealers.
Hello and thanks for the truly wonderful website! Well, I’m getting lazy and about to make a mistake. Today, I spent the day obsessively cleaning my approx 400 sq ft concrete garage with Purple Power Driveway and Concrete Cleaner, deck brush and power washer. A few faded stains remain, that I can live with. I do have a small concern about a three approx 2 sq ft patches that appear to be less porous. My inclination is to seal away with PS101, when it dries tomorrow. What is the worst that could happen?
Hello Ron. As long as those patches will absorb water, then they will absorb the sealer. If the water just beads up or sits there, then so will the sealer and it will not be effective in those areas. We do suggest, however, that you wait more than 24 hours for the concrete to dry. Preferably 48 hours at a minimum. The reason is that pressure washing drives water deep into the concrete and it takes longer for it dry out. You are applying a penetrating sealer reacts with dry concrete. While it may be dry on the surface, it will still be damp below the surface and the sealer will not react with the concrete like it should.
Shea,
I had a new slab poured for my shop and want to use a siliconate sealer for all the reasons that you listed above. Question is how long do I need to let the new pour cure before applying the sealer? I’ve heard anywhere from 30 days to 6 months and looking for some clear advice.
Coatings always require a minimum of 30 days John. Penetrating sealers on the other hand can go on in as little as a few hours after the pour depending on which type of sealer used. Some require that you wait 30 days minimum just like a coating. We do know that PS101 by Concrete Sealers USA can be applied same day after troweling. It will help to cure the concrete. If you give them a call they can give you the specifics. Foundation Armor’s SC25 is another example. It can be applied right after the bleed water and finishing are done.
I wish I had read the comments sections first as I have already patched the cracks in my concrete floor with Rust-Oleum’s Epoxy Concrete Patch Kit. I want to apply a siiconate sealer to the floor but it appears from one of your responses to a previous comment that this would not be compatible. I have moisture issues as well spalling and live in Canada where salt and freeze thaw is a major concern, What course of action should I take at this point?
No worries Jeff. The patch repair kit is a 2-Part epoxy. It’s resistant to liquids, salts, oils, and freeze thaw since liquids cannot penetrate it. You can still apply a siliconate sealer, it just won’t penetrate the epoxy repair material, which it doesn’t need to do anyway. It will still treat the concrete around the repair material, however, just fine.
Hi Shea,
I am trying to figure out the best option and product to use for my garage floor. The penetrating option seems to fit everything I want which is mostly not slippery and protecting against the salt from the car. You mention PS101 and looking around my City I haven’t been able to find it. I did find a product from IMCO that is called Crystal-Lok 470 or 470 D-Tech. Would this product be equivalent?
There is a wax type sealant existing from around 5 years ago. My plan was to sand that off and apply an etching before applying the sealant.
Thanks in advance for your time!
Hello Joel. Crystal-Lok looks to be a densifier and not a siliconate sealer. Finding these types of products from home improvement centers is difficult if not impossible. They generally need to be purchased from vendors online who specialize in concrete sealers and coatings unless you can find a concrete contractor supply company. Those types of businesses tend to carry good commercial product.
Also, we recommend giving customer service for these companies a call and tell them about your project. They generally are very helpful and much more knowledgeable about product and application than the help you find at brick and mortar stores. The two examples we mention in our post, Concrete Sealers USA and Foundation Armor is a good place to start.
Thank you. I will contact Concrete Sealers USA and see if they can help me out on the Canadian side.
Very informative site. I’m converting an old one car garage into a wood shop, and I’d like to control the moisture in the space by sealing the slab which is broom finished concrete from the 1920’s. Will a penatrating sealer lock out dampness below the slab?
Hello Kevin. Penetrating sealers do an excellent job at blocking dampness, but it really depends on how much you dampness you have and what type of sealer you use. Siliconate sealers do a great job for most situations. We always recommend contacting the manufacturer, however, if you have any doubts or questions about any particular project.
I’ve been reading about silocanate sealers and though they say that they make concrete more resistant to surface water you may spill on the floor, they don’t say anything about reducing moisture from coming up through the slab. The slab I’m working with is above grade so this isn’t a huge issue but I’m still looking for a product that will isolate ground moisture from the interior space. Silocanate sealers say they allow concrete to expel water vapor. Couldn’t that be from ground water? Can you clarify?
Hello Kevin. What you are referring to is negative side water proofing. No sealer really does that, that’s what vapor barriers are for. However, most penetrating sealers will do a good job of blocking or slowing down moisture from underneath as long as it’s not a serious issue of a high water table, broken pipes, basement floors in a wet climate, or below grade slabs with high hydrostatic pressure, for example. Most penetrating sealers are breathable. This means they stop the water molecules from traveling through the sealed layer, but allow the vapor to continue. The water vapor will not cause the surface to dampen. The water vapor cannot carry the salt and minerals with it either like water does. For example, efflorescence is caused when water migrates to the surface. It carries the minerals and salts with it. When the water evaporates at the surface, it leaves the minerals and salts behind in the form of a white powder. Sealers prevent this from happening.
I am having a new wood shop built with a concrete floor and footings in a monolithic pour,
I want to apply something to it before moving in the machinery to protect it and reduce the concrete dust,
What do you suggest?
The sq. footage is 720.
It depends on what you want to protect it from Bill. What are you going to use the space for? If concrete dust is your biggest concern, then a lithium based densifier is a good choice. It will reduce any potential for dusting and harden the surface at the same time. If you want protection from things like freeze thaw, road salts, and other chemicals, then a siliconate sealer is a good choice.
Does anyone know how to remove a penetrating sealer, or at least make the concrete more porous again? I have it on a patio and it stays wet too long.
You would need to grind it off Matt. Penetrating sealers cannot be removed via chemical means. Keep in mind by doing so, your concrete will be susceptible stains and other damage that the sealer protected it from.
Thanks for the reply. How deep do I have to grind down the concrete? Would sand blasting also help too?
Not sure how deep the penetrating sealer goes? I have the type of penetrating sealer down that has no effect when dry, but beads water and doesn’t absorb when wet.
Hoping to make it more porous again. If I do nothing, will the concrete ever become more porous on its own again?
Hello Matt. What is your end goal with the grinding?
My end goal would be to have the concrete become more porous again. In my stupidity and lack of product knowledge I applyed a penetrating sealer to a covered patio area. Now when it gets wet, you spill a drink, etc. the liquid just pools on top and takes forever to go away. I just want my regular old concrete back 🙁 Big mistake putting this product under a shaded covered patio…
I see. You do realize that the sealer helps to protect the concrete from staining though right? An aggressive grind with a 10″ Edco machine or a 7″ turbo cup wheel on an angle grinder will bring back most of the porosity. Just keep in mind that the grinding will create some patterns on the surface. They will slowly fade as the concrete ages, but it will take a few years.
Thank you so much for the help Shea! I REALLY appreciate it. I will think about the grinding before I try it. One last question: How long do these penetrating sealers last before they just get porous again on their own? I used the Seal Green product…
It depends on the type of sealer (ingredients) used Matt. Some use a lot of silicone which tend to sit more on the surface and wear out rather quickly. Others, such as silane, siloxane, or siliconate, penetrate deeper and last for years. They only wear as the concrete wears.
Yes, I believe it was a siliconate sealer, so I guess I am looking at years & years. I suppose grinding is my only option, but i’ll make sure to weigh the pros & cons some more first. You’re a tremendous help, thanks for your insight.
Hi,
Thank you for your site with so much information. I’d like your advice on what to do for the concrete floor. The basement in my 90 year old house had crumbling areas that were painful to walk on in bare feet. We’d sweep/vaccum and the floor just kept crumbling. It also had various sections with 90 years of sealer/paint/stain that peeled in some parts. I used a floor buffer and the removal Diamabrush attachment and now have concrete that feels like sandpaper. There are many empty puddle looking sections where I knocked all the loose spalled concrete away. There were also small sections where I focused on the previous coating but it did not come up. It is now well scratched and water doesn’t bead but the coating isn’t budging. There aren’t any cracks in the concrete, just unevenness. The floor passed the moisture test but I am skeptical. Now for advice. I want something that protects the floor. I don’t want any moisture or for it to crumble. Those are my priorities. If it is possible to get a level(ish) floor that looks nice, that would be great but it isn’t worth a huge investment of time and money to me. I don’t want to add weeks to my project. What would you recommend? The only real constraint is I never want to lug a floor buffer down and back up my basement stairs ever again. Please advise. Thank you so very much.
Hello Carolyn. With a floor that old and in the shape that it is in, there is only so much that you can do. If you want to remove the remainder of the coating in the small areas, a 4″ angle grinder with a 4″ concrete turbo cup wheel will take it up in nothing flat. It will produce a lot of dust however. In terms of your requirements, we recommend a couple of coats of a good densifier. It’s not worth spending much more than that. Densifiers help to increase the strength of concrete as well as seal it from within. The more deteriorated the concrete, however, the less effective it is. If the concrete is not dusting too bad it should do a good job. We suggest contacting Concrete Sealers USA or Foundation Armor. Explain what you are dealing with and that you are interested in a densifier.
Will a siliconate sealer stop smell? I bought a house which had cats prior (50~ at one time) the garage still smells. The garage has been power washed, and treated with cleaner. I’ve painted the walls with several coats of paint, and think that the smell is now coming from the floor. Would a siliconate sealer stop the smell?
Thanks in advance,
No it won’t Chad. Penetrating sealers such as siliconate are breathable. Odors will still come from the concrete. What you need is an actual coating such as epoxy. Epoxy does not breath and will not allow the odor molecules to pass through. You first have to prep the surface of the concrete by acid etching or grinding before application of the epoxy. Once the surface is prepped, treat the concrete to an pet enzyme urine cleaner. This type of cleaner works much better when the pores of the concrete are open from the surface prep. Once the floor is completely dry (24-48 hours) you can apply the epoxy.
On a side note, we know from experience that painting walls will not remove pet odor as well. Acrylic wall paint also breathes. Your best bet is to replace the lower 3 feet of drywall to get rid of the odor there.
I have a new (2 weeks old) garage floor. surface is totally smooth. Interested in using either sealer PS101 or Armor SC25. Can I apply it directly or need to do any kind of prep? please let know and thanks for the great info on your site
Hello Rico. As long as the concrete will absorb the product there will be no need to prep the surface. You can test for this by applying some water drops in various places on the surface. Agitate the drops if necessary with a broom. If they slowly get absorbed into the concrete within a few minutes or so you are good to go. If they bead up and just sit there without penetrating the surface after more than 5 minutes, then you will need a mild acid etch first.
I had asked in October about sealing a cast in place capped garage floor – you had said to use a siliconate penetrating sealer and had recommended either PS101 or Armor SC25. My local Stetson building products store sells Prosoco Saltguard penetrating sealer. I am going to use this on a sidewalk I poured about 45 days ago. Would this be a good sealer for my cast in place capped garage floor also? Thanks
Hello Gary. We’ve actually used that exact sealer for the flagstone around a pool. It is a silane/siloxane mix that works very well against chlorides and salt. It will work in the garage, but it will need a heavy application since the silane penetrates deep. Since it will see vehicle use, you will also need to reapply it every couple of years since the siloxane is a derivative of silicone. The silicone sits more on top of the surface (it makes water bead0 and gets worn away. It’s not our favorite for a garage though. The reason is that the silane/siloxane mix is hydrocarbon based and as such can allow chemical chains to remain active in the concrete. Upon dissappation (after a year or so) or upon too light of application, this active chemical chain is looking for other chemistries with which to react. What this means is, a spill of another hydrocarbon such as oil, transmission fluid, gasoline, diesel fuel, or gasoline type products can result in a stain that permanently attaches to the remaining active chemical chain. This can produce a permanent stain in the concrete that can never be cleaned except through removal of the concrete. So while it makes for a good sealer for walkways, pool decks, walls, and etc, it has it’s disadvantages for a garage floor.
I have a garage that currently has 80% carpet glued to the floor, and 20% tile. Apparently someone used to live in there. I would like to apply a sealer, and I plan to use a Diamabrush remover head to clear up the glue and thinset.
1. What is the difference between the Diamabrush revmover head and the grinding or prep head?
2. Is the surface finish of a Diamabrush too rough to use with a sealer type finish?
3. I don’t care too much about the appearance of the floor, I will be working on cars on this surface which is why I want to protect it from automotive fluids. Is it really necessary to repair cracks?
Hello Jesse. The Diamabrush removal tool has less blades than the prep tool. Less blades is actually better since they will not have a tendency to clog like the prep tool would do. The profile of the concrete surface after you grind will be fine for any type of penetrating sealer you plan to use. You don’t have to repair the cracks if you don’t want to. Just keep in mind that if fluids like oil run into the crack the concrete will soak it up like a sponge and the edges of the cracks can turn black.
Hi Shea,
Is there any value or need to use a densifier and a siloconate sealer on a brand new garage that will serve multiple purposes (garaging and working on cars, tool shop, cold storage and wood storage)? If so, is there a good combined product. Again, if so in what order would they be applied and within what time interval? Is there benefit to be derived from multiple coats of either product?
Another question: my garage is power troweled and it is a concrete with fiberglass. I plan to grind (polish) it to 3000 grit. At which stage of grinding should I apply the above two products (before, in between one or another of the grits or afterward)?
The GhostShield’s product, Siloxa-Tek 8505 (?w/ or w/out TL37 densifier), seem to offer the same properties as eiither PS101 or Armor SC25, except that the other product(s) claim a superb resistance to oil. Any comments? It is difficult for me to decide upon a product. My only real conclusion so far is that I want to use densifier along with a sealant.
A final question: I have PEX heating line under some portion of this space. Is there any chance that these products might compromise the tubing?
Thank you very much. I very much enjoy your site!
Roy
Hello Roy. We will answer your last question first. No, the PEX heating line will not be compromised. In fact, it’s very common to have various types of radiant heating with concrete floor finishes.
Regarding the sealers; because you are polishing your concrete, it rules out most typical sealers such as PS101 or SC25. These are large molecule sealers formulated for bare concrete that has not been altered by polishing. The polishing process requires the use of a densifier at least once, if not multiple times during the polishing process. A 3000 grit final grind is extremely smooth and will not accept most sealers. A low solids stain guard is sometimes buffed into the surface after the final grind, but these do not resist petroleum products well. In fact, there is still debate among polishing contractors if a stain guard should even be used. GhostShield 8505 will not be effective since enough cannot penetrate the highly polished surface.
Based on how you plan to use your garage, you may ultimately be unhappy with polished concrete. It will require routine maintenance to keep the polish up and it will not be impervious to stains from petroleum products. It looses luster fairly quickly under those conditions, even more so if you live in a winter climate and will be tracking in road salt or deicing fluids. It’s not a recommended floor option for most garages.
You may want to look at this floor that was done by one of our readers. He used a stain guard to buff a gloss into a power troweled floor. It’s a much less expensive process that provides an almost equivalent resistance to stains as a polished floor.
Hi Shea,
I would like to get clarification on using a penetrating sealer with an epoxy coating.
I live in the Midwest, and do have water issues near the garage door only. (The plastic sheet test passes with no car using the garage and failed if I use the car every day,). Reading the most common installation issues when installing epoxy coating you mentioned a sealer could be used to help with moisture. But in one of the above comments you mentioned the floor would need to be re-etched if they were to install epoxy.
So can I use a penetrating sealer, if I grind the floor use the penetrating sealer than apply epoxy coating?
One thing to keep in mind Matt, is that moisture problems originate from the underside of concrete. If the slab near the entrance gets wet at all or is exposed to humid air, it will emit moisture during the warmer parts of the day. Concrete is like a large sponge and can take in moisture from the air at the surface. If a coating is applied, then the concrete surface cannot absorb moisture to begin with. If you truly have an issue with the moisture coming from the underside of the slab, then a densifier would be the best treatment. It will penetrate the concrete and help fill the voids that allow moisture to travel through the concrete. A densifier takes about a week to react and take effect. After that you can moisture test and if it passes, you will need to grind the surface of the concrete (not etch) to provide a mechanical profile for the epoxy to adhere to.
I recently moved into a house that already had a painted garage and baselment floor. About half of the paint has peeled up. After reading the articles on this website, I expect a penetrating sealer with a densifier to be my best option as my garage is always covered in cement dust no matter what I do to try to wash it away. I’ve read that the best way to remove the paint is to grind the floor, but those articles are always in preparation for an epoxy coating. What would you recommend as the best approach to remove the paint to replace with a penetrating sealer?
We recommend the same process Steven. It’s the easiest way to remove the paint and it will help to remove any excess laitance on the concrete surface as well. This laitance is one element that contributes to dusting. We have an article about grinding a garage floor and applying a densifier that you may find useful. You can read it here. The other way to remove paint is to use a chemical stripper. The process can get quite messy and it does not remove excess laitance.
Hi, Shea
Thank you so much for all the info you provide on this site.
I have a mostly enclosed 500 sq.ft. 2 car 1950’s attached carport where now that I am a retired art teacher I will continue to teach art lessons. The space is to become totally enclosed and air-conditioned. Plus it will have a dehumidifier. I have just finished pressure washing the concrete floor. Some mostly rusty stains remain but also other stains where the water beads up. They must be oily areas which I will need to address and I wonder how to best clean those with the final sealer in mind. Also, I’ve observed moist/slick areas when the weather has been very humid.
I doubt the floor was ever sealed. There are a few cracks and some small, deep pits. The texture looks like it may have been a broom finish and it is very porous. My floor does not need to appear pristine but I do want to minimize concrete dust and moisture (from above or below) and to keep the floor clean by wiping up any spills and by mopping. From what I’ve read here I think my choices are to use either a silacanate sealer or to use a densifier/silicone combo. Am I on the right track? Would the densifier be the better route? Thank you!
Hi Linda. We recommend reading our article about removing oil stains to get some tips for that. The moisture on the surface when it is humid is most likely what the industry refers to as “sweating”. That is when relatively warm moist air comes in contact with a cooler surface and condenses. Since you are enclosing the space and air conditioning as well, you should not have anymore issues with wet spots. If your main goal is to reduce dusting and make clean up easier, then the proper siliconate sealer would be a good choice. If you had moisture issues from below the slab and/or heavy dusting, then a densifier would be the better option, but it doesn’t sound like you have that. Concrete Sealers USA makes and excellent siliconate sealer for porous concrete. It’s called PS102 and you can purchase it here from Amazon if you wish. It will do a good job of filling all the porous voids and capillaries at the surface and it will not change the look of the concrete.
Hi
I have recently completed my house with a concrete floor, and at the moment can not afford to do the Tiling. I am looking for a product that I can use to keep the cement dust away but that I can also tile over at a later stage. Would the siliconate sealer work for this or is there another product that you can recommend?
Thanks
Hello Jared. If you want to keep the dust away and tile later, then a straight densifier would be the better choice. A siliconate sealer is a moisture blocking sealer that would inhibit mortar from adhering very well if you tile at a later date. Densifiers are technically not moisture blockers however. They cause a chemical reaction in the concrete that fills the empty capillaries and voids near the surface. This hardens the surface and help prevent dusting. L3000 by Foundation Armor is a good densifier. We did a review on it which you can read here.
Hello Shea – Really have enjoyed reading all the expert help you have provided here ! I have a new home with concrete floor poured 9 months ago. No moisture problems, or odor but decided I wanted to make it nice looking with an epoxy coating. First step was citric acid etching, which didn’t seem to go very well. The driveway turned chalky so I guess I etched part of it, but still some residue and different colors in the floor. Parts of the floor look damp now so i guess it is partially etched. I have been discouraged by the builder about going forward with the epoxy – saying it won’t adhere that well and may lift. If I want a non-slippery, concrete floor that will resist oil, gas or water, I just need a sealer now ? What should I use ? If the floor is partially etched and I do nothing else, it will get dirtier now right ? What if i re-do the citric acid , scrub it thoroughly, let it dry REALLY well and then seal it ? or would you just scrub the residue with water, dry and moisture test it ? I just want my concrete back with a non-slippery surface? thanks so much.
Hello Lindsay. What do you mean about your driveway turning chalky? Did you etch your driveway or your garage floor? What product did you use? Also, did you check for a sealer on the surface first before you attempted the etch?
I applied a bag of citric acid solid dissolved in 2 gal of water with a watering can, scrubbed it and rinsed it thoroughly and then used a squeegy to remove excess water. These are the precise directions given for etching the concrete in the Rustoleum epoxy kit for garage floors. In some places there was ‘steam’ and color change in the water (turning brown) when i applied it and scrubbed, but in other places nothing. I did nothing to the driveway, but the chalky deposit appeared because of the excessive rinsing from the garage to the driveway in front of it. (Most of it has washed off with the hose). This seems really dumb, but i was wearing sneakers and began to see white footprints where i had been standing, so maybe the acid was etching plastic from the shoe. Water did not bead up on the initial concrete so I don’t think there was a sealer. Right now, damp spots remain for a long time on the floor, making me think it is at least partially etched. I’m really hoping you can help. The garage floor seems damp and multiple colors.
I was wrong about the garage floor. It was poured in April – so the concrete is 90 days old. I checked with builder – no sealer was put on the floor. The builders do not recommend any of the epoxy products. Right now I think I have a partially etched, 90 – day old concrete floor. I could really use some help if you have any ideas. Thanks !
The problem with the Rustoleum product, Lindsay, is that it’s an ECO friendly citric acid etch. It’s not very strong. It’s designed to be safe and just effective enough to get the low solids, water based epoxies to penetrate and adhere to the concrete. If your concrete had a real smooth finish or is fairly dense, then it does not work very well. Our guess is that is has only partially etched the concrete. Also, etching does not produce predicted results like grinding concrete does. It’s not uncommon to have darker and lighter areas. Regarding the white powder on the driveway, it’s always recommended to hose down the driveway first before you rinse out the etch. The white powder is the residue from the etch breaking down the concrete surface to open up the pores.
Our recommendation would be to use a muriatic or phosphoric acid etch. It is much stronger and will etch your concrete correctly. We have an article on how to acid etch here. Since you confirmed your concrete did not have a sealer applied, it should work very well. After that you can apply your coating of choice. If you don’t want to apply a coating after you etch again, you can always apply a penetrating sealer instead. Keep in mind though that they will not change the look of the concrete. Make sure to give the concrete a couple of days to completely dry out. If it’s humid, it may require an extra day or two.
Shea – I think you described my concrete floor perfectly – lots of variations in color and very smooth on the surface, even after 6 gallons of citric acid solution ! Since I already bought the Rustoleum epoxy kits, are you saying that they will work fine after a phosphoric or muriatic etch ? If I decide not to use the epoxy, do you still recommend completing the etch with the acid before sealing it ? (versus leaving it as is ) ? Finally, its not a problem to acid-etch a 90 day old concrete floor ? I really appreciate all the help !
Yes, the Rust-Oleum kits will work fine after you etch with a strong solution and a 90 day old concrete is fine. If you decide not to apply an epoxy coating, etching with a stronger solution will help to even out the color of the concrete a bit better regardless. If that is not an issue for you, then you could seal it now if you liked. You may want to read this article about epoxy paint kits just to make sure the product you purchased is what you want.