A new trend that has been finding its way onto the surface of garage floors and workshop floors is the use of a concrete densifier with an added sealer. Densifiers have been used on occasion in the garage for a variety of reasons, but rarely as a finished garage flooring treatment. So why has there been a gradual increase in its use and popularity for the garage floor?
The reason has to do with the addition of silicone and siliconate agents in some densifiers to act as a sealer. This helps to create not only a water repellent floor, but one that is resistant to liquids and chemicals in general.
In fact, this combination of a densifier and sealer has fast become one of the best values for a bare concrete sealer.
So let’s take a closer look at how a concrete densifier with sealer on your garage floor may be beneficial for you. In addition, we will discuss what product we highly recommend and why.
How a concrete densifier works on a garage floor
Concrete densifiers have been around for decades. They are a concrete hardener that has primarily been used for concrete floor polishing, increased abrasion resistance, anti-dusting, and moisture mitigation. They are typically applied to machine troweled, hard troweled, and smooth concrete.
In some cases, they are used to treat a soft concrete surface or as a treatment for dusting concrete.
When concrete cures, bleed water makes its way to the surface and increases the water to cement ratio. This process can help to make the surface of concrete smooth. However, it can also create a surface that is softer than the underlying cement. This is due to the increase in laitance content and fine aggregates that the bleed water carries to the surface.
When a densifier is introduced, a chemical reaction is created that can increase the surface strength of concrete from an average of 20% to 40% depending on the original pour and finish of the concrete. But, how is that done?
Densifiers are a water-based chemical solution that first works by penetrating into the surface of the concrete. They react with calcium hydroxide to produce calcium silicate hydrate (CSH). This is the substance that gives concrete its strength.
Next, the CSH that is produced fills the open pores and capillaries of the concrete. This is what increases the density and strength at the surface.
Lithium silicate densifiers are the most common choice used for garage floors and workshops. There are two chief reasons for this.
The first reason is due to the ease of application. Scrubbing in the densifier solution typically is not required like it is for the older sodium silicate densifiers.
The second reason is that lithium silicate has properties that are less reactive to carbon dioxide which can create a whitening effect on the floor. And unlike sodium silicate densifiers, lithium silicate densifiers also do a good job of repelling road salts. Once applied, the concrete retains its natural look.
It’s important to note that concrete densifiers are non-film forming, meaning that they don’t leave a topical film on the surface to protect from staining.
Additionally, densifiers technically are not water-repelling sealers either. They don’t form the same molecular membrane at the sub-surface to repel liquids as other non-densifying penetrating sealers do. This is why they had not been used much as a concrete protectant for garage floors – until recently.
With the addition of silicone and siliconate agents in densifiers, their use as a sealing agent and overall protectant for garage floors has dramatically changed this. These siliconates create a water-resisting agent right at the sub-surface of the concrete.
This addition allows the densifier to act as a sealer for your garage floor by repelling water, resisting oils, and resisting stains. Furthermore, it protects the concrete from chemicals such as road salts, and other fluids.
Lastly, densifiers with siliconate sealers added are environmentally safe. They are extremely low in VOCs and odorless.
Are they 100% impervious to stains and chemicals? No, but if you don’t allow spills to sit for a long period, they will generally wipe right up with little if any scrubbing necessary. However, you must be particularly careful with solvents that can stain, as their resistance to them is minimal.
The benefits of a concrete densifier with sealer added include:
- Added strength and abrasion resistance to the surface of a working garage
- Increases the compressive strength of concrete
- Repels liquids and other fluids which help to make your garage floor stain resistant
- Eliminates dusting and problems with efflorescence
- It doesn’t peel, leave tire prints, or turn yellow
- Helps act as a moisture barrier for your garage floor
- Improves weathering and resistance to freeze/thaw effects
- Non-slip surface
- Relatively inexpensive
- Lasts for years without need for reapplication
- Easy to apply and is ready for traffic within an hour or two
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Concrete densifier sealers we recommend
One particular densifier sealer that we highly recommend is PS104 by Concrete Sealers USA. Why?
This is the same company that manufactures the very highly rated PS101 siliconate sealer which we have discussed before.
The same siliconate sealing agent that is used in the PS101 is added to the PS104 densifier. This is what makes PS104 such a high-performing concrete sealer and densifier. It’s all in one product.
In addition, with an average coverage rate of 200 – 300ft², it makes for a very affordable concrete sealing option. Concrete Sealers USA offers it in both 1-gallon and 5-gallon containers.
Check Price of PS104 – 1 Gallon
Check Price of PS104 – 5 Gallon
Furthermore, we also like the amount of lithium silicate (measured in solids content) that is used in PS104. Manufacturers generally have to perform a balancing act between how much lithium silicate can be included for densifying purposes and how much siliconate can be added for sealing the surface.
If too much lithium silicate is used, it makes it difficult to add the desired amount of siliconate for the best sealing performance. It also makes the product more expensive.
As a result, many of the densifiers with siliconate sealer added have a lower solids content of the lithium silicate in order to keep the price point down and manufacturing of the product easier. The results, however, are less effective densifying properties.
Concrete Sealers USA has found a way to use almost the same amount of lithium silicate in their PS104 as they do in their standard PS103 densifier. As a result, you can expect close to similar densifying performance as a straight densifier plus the added benefit of the siliconate sealer.
How to apply a densifier to a garage floor
The application of a densifier sealer for your garage floor couldn’t be much easier. You first need to make sure your garage floor is clean and free of all dust, oils, and foreign contaminants. Any stains that you have will essentially be locked in unless removed first. The surface must be completely dry before applying the product.
The easiest way to apply the densifier is to use a garden sprayer with a circular spray tip or a microfiber mop out of a paint tray. Work in sections making sure to keep a wet edge at all times.
You want to get the concrete wet with the product, but not so much that it puddles. If it does puddle, work it into the concrete with a short bristled deck brush or wipe up the excess. If you allow the puddles to dry, you will get a white residue that requires intense scrubbing to remove.
Once applied, you can return the floor to traffic within a couple of hours or so. One application is generally all that is required.
One note to make is that if you plan on adding a topical coating at some point in the future, you will need to grind the concrete in order to remove the sealer and provide a mechanical bond for the coating. Acid etching will not work because the etching solution will not be allowed to penetrate the surface sufficiently in order to react with the concrete.
If you like the look of bare concrete and have a working garage or shop floor that you want to protect without making a big project out of it, then a concrete densifier with sealer added can be a good solution for you. It’s easy to apply, relatively inexpensive, and will provide years of protection for your concrete. In short, it’s one of the best values in concrete sealers today.
Max says
I live in Ohio and own a home that is almost 50 years old. The garage floor is in pretty good shape with not many stains but I have a problem with dusting and just a little bit of pitting. I think it might be from age or from the road salts in winter. There isn’t a coating on the floor but I don’t want to spend a lot of money. Will a densifier like this work on old concrete and will it stop the dust problem?
Shea says
Hello Max and thanks for visiting our site. Yes, it sounds like your floor would be a good candidate. Densifiers will strengthen the surface of old concrete as well as new. If you apply a densifier sealer to your floor, it should stop the pitting and the dusting problem as well as make your cement resistant to the watery salt chemicals that are so corrosive to concrete.
Dominik says
My garage floor is a bit soft in a few places, and also a bit uneven. It extends a few inches into the driveway as well, so after reading this article I thought the best solution would be to use a concrete densifier on the entire surface, “without the silicone/siliconate additives”, as you say, and then seal it with epoxy or polyurethane.
I’m a bit confused with the terms though: most concrete densifiers say they contain potassium, sodium, or lithium silicate. I am not sure if this is the same as the silicone/siliconate that you mention. Secondly, it seems impossible to be 100% sure before purchasing that the densifier will be a good fit for a later epoxy/polyurethane application. Could you recommend a specific product for this scenario?
Many thanks!
Shea says
Hello Dominik and thanks for the great question. I can see why the terms can get confusing. The silicone/siliconate additive is just that – an additive that creates a sealing property similar to a penetrating sealer. The product will clearly state that it has been added for either waterproofing or sealing properties and will be sold as an added benefit. The chemicals that make up a densifier are a type of silicate (notice the spelling), either sodium, potassium, or lithium. Lithium silicate densifiers are the easiest to apply and the most common for what you want to do.
Yes, you can epoxy concrete that has been treated with a standard lithium densifier and it is done occasionally to harden softer concrete surfaces before grinding. You still need to prepare your concrete properly for epoxy after the application of the densifier. Here is an example of a product from Legacy Industrial that will do just what you want. They have good customer service and are happy to answer any questions you may have.
Gary says
I have a Pole barn floor that seeps moisture from below, to the point of puddlin. Do you think this product will stop or reduce this problem? Or what would you recommend instead?
I thought the best solution would be to use a concrete densifier on the entire surface,
Thanks for you help!
Shea says
Hello Gary and thanks for stopping by. If you have water puddling on the surface then you have a more serious issue. This product is not going to stop it completely – it will slow it down quite a bit, but not stop it. What you need is a deeper penetrating moisture barrier type of sealer that is typically used for basements. I would contact these people here at Bone Dry Products and explain your situation.
Tom says
Hello, Shea! Here’s my situation…my garage floor has a thin, peeling, 12 year old cheap epoxy or paint coating. I’m considering grinding w/the Diamabrush & angle grinder, rolling in a beige colored stain from Super-Krete (or comparable), then applying a concrete densifier with siliconate sealer. How would this look & perform? If I skip the stain, how would the ground concrete surface look? Thank you! Really appreciate your articles!
Shea says
Hello Tom. Because you may need to grind the floor, an acid stain may not take as well since it needs to react with the lime on the surface that will be removed by the grinding. Check with the stain manufacturer and ask about a sample to test in an inconspicuous area. You can do a water based stain after grinding, but they can fade a little if part of your garage is exposed to sunlight all the time. If it’s paint on the surface and not epoxy, you can do a chemical strip instead with a good scrubbing afterwards if you want to do the acid stain. Here is more info about stains.
Stains need a film forming sealer to protect them as well as to give the color some pop. A densifier with siliconate sealer will help with the color but does not do as good a job at protecting it from wear. A clear epoxy top coat is the most durable sealer but is more labor intensive. Another suggestions is an epoxy/acrylic hybrid such as this, which is much easier to apply. This type of sealer also looks nice with ground concrete as well.
Tom says
Hello again, Shea. I should have said that after removing my old, peeling epoxy or paint finish, by either chemical stripping or grinding if necessary, I was considering a color dye (not acid staining). I guess I would use the non-water-based type of dye, followed up by….what, to protect it from hot tire pickup? No direct sunlight hits the floor. Would like a low gloss finish, non-slippery to walk on. Thanks again, I’m learning!
Shea says
Hey Tom. You have a few choices depending on how involved you’re willing to get. Solvent based dyes are really vibrant with many color selections. Again, we recommend looking at this acrylic/epoxy hybrid. It’s easy to apply and protects from hot tire pick up. Its also very easy to reapply as it wears. If you grind you can apply an epoxy primer followed by a top coat of polyurethane in a matte finish. This will give you superior chemical and abrasion resistance and a floor coating that will last for years. Both of these finishes can be a little slippery when wet. You can easily add a fine anti-slip additive to the final coat.
Meng says
I’m building a new garage with a pex embedded in the concrete for radiant heating as well as floor drains installed. I plan to seal the concrete after it has cured.
One of my goals with sealing the concrete in my new garage is to keep the surface non-slip. I know other concrete coatings offer non-slip properties (usually through additives applied in the top coat). Since concrete densifier is a single application I’m wondering if it’s an appropriate product for sealing concrete while leaving a non-slip surface? I live in a cold climate, in case that has any bearing on the answers/advice you provide.
Essentially I’m looking for the best product to seal my concrete and leave a non-slip surface for the lowest product price. Any help you can provide would be greatly appreciated.
Shea says
Hello Meng. Whether you use a densifier or a penetrating sealer, either one will leave the surface with the same non-skid properties as bare concrete. They are both non film forming meaning they will have no effect on the surface grip. Most can be applied to concrete withing a day or two of the pour to help with the curing process as well. Both options are relatively inexpensive and easy to apply. As a tip, home improvement centers generally are not the best place to find the best product.
Meng says
Shea, thanks for the reply. It sounds like both the densifier and penetrating sealer would be excellent options for me not only to seal, but to help cure my new garage floor. I’ve read through both articles on your site for the products you recommend, but the information doesn’t seem to declare one as superior over the other. Do you have a recommendation for which you would choose if you were pouring a new concrete garage with in-floor radiant heat and floor drains in a cold and snowy winter climate location?
Shea says
Because you live in a snowy climate and have floor drains in anticipation of much moisture, a penetrating sealer is going to provide the best performance for you over the long run.
Meng says
Thanks for your expertise and replies, Shea. In browsing around your website I am impressed by your thorough articles, but REALLY IMPRESSED at the prompt and thoughtful answers to questions you receive in the comments area. It’s a testament to your commitment to the subject matter. Kudos.
Shea says
Thank you Meng, we appreciate your compliments.
Don Grove says
Thank you so much for your very informative sites, Shea. Like Meng I am trying to decide between a penetrating siliconate sealer and densifier sealer. It sounds like the densifier sealer has siliconate sealer included so does two jobs. Do I have that right? We just built a house and would like to inexpensively protect the garage, driveway, patio under an aluminum deck (no water comes through deck) and interior basement concrete, some of which we might eventually paint or put vinyl on. Which do we use penetrating siliconate or densifying sealer? Thanks again for a great site. Regards, Don
Shea says
Hello Don. Penetrating sealers were originally intended for driveways, walkways, and patios and would be the best choice for those areas. They also do very well in the garage. Considering all the concrete that you want to seal, your best bet would be a penetrating sealer since the price goes down with quantity. As far as your basement goes, you need a different type of sealer for interior basement walls.
Marc says
Hi Shea, if cost is not an issue, then would the densifier with sealer be a more durable option? I will be doing my garage, driveway, patio, and walkway. I am in southern California, and the concrete is new. My main concern is dusting, cleanliness, etc., but I would also like to reduce the risk of cracking.
Thanks,
Marc
Shea says
Hi Marc. Sure, you could use a densifier sealer for all those jobs. Keep in mind that a densifier is not going to prevent concrete from cracking however. It strengthens the upper surface of the concrete, but it would not resist the shear forces and other scenarios that cause concrete to crack in the first place.
Kim says
Shea: I have a 8,000 sq ft rock club with raw concrete floors. We are grinding the floors now that they are cured and are considering choices. Since I’ve got an indoor venue in Mesa, AZ I don’t have to worry about freezing or UV.
We tend to have lots of liquid spills (beer!) and gum on the floor to clean up. And we’d want to retain slip resistance.
I’m interested in the penetrating siliconate sealer and/or densifier sealer as the raw concrete look is ideal for our industrial vibe.
How do you think penetrating siliconate sealer and/or densifier sealer compares vs expoy or poly for our application?
Thanks…
Shea says
Hello Kim and thanks for the visit to our site. If you want to retain the looks of the raw concrete for the industrial vibe, then a penetrating sealer would be the best way to go. It will provide good slip resistance when the beers start finding their way to the floor, but keep in mind, some spills with color (mixed drinks) left unattended for long periods of time may still leave a slight stain that would need some scrubbing. Chewing gum can usually be scraped off the floor without leaving a mark when using a penetrating sealer.
A good topical sealer combo would be a clear epoxy primer with a polyurethane top coat. It would be extremely difficult to stain and will last quite a few years under the conditions. Polyurethane is available in a matte finish to retain some of the raw look and not look glossy. This type of system will cost much more however. It can be a little bit slippery when wet, but you can apply a non-slip additive to the final top coat.
For such a large area, we recommend that you contact V-Seal. They have years of experience sealing large concrete floors for special events, amusement parks, and industrial parks. I believe they would have a penetrating sealer that would get the job done for you.
Jon says
Hi,
I see that you have stated that this product can help with dust prevention and that’s something that I’m definitely interested in. Do you have a sealer or recommend one with at least a five year warranty against dusting?
Shea says
Hi Jon. Because dusting can be due to a variety of reasons, one of which is a bad concrete mix, manufacturers of sealers and densifiers do not warranty against dusting. As long as you don’t have a sandy top, these type of products will knock down the dusting for most applications. If you can put a groove in your concrete with a screw driver then your surface is too soft and a densifier will not help it.
Martin says
I have a garage on top of a garage in a 50+ year home. The floor/ceiling between the two garages is poured concrete. Over the years the floor of the upper garage has collected its fair share of snow from the road and over time it must be seeping through the bottom garage through the concrete. The floor/ceiling when looked at from the bottom garage, is starting to show it as it’s starting to crumble.
Would a concrete densifier/sealer help stop the deterioration of the concrete? Is there a better approach to keeping the concrete floor/ceiling in shape? Thanks in advance.
Shea says
Hi Martin. Yes, you can stop the damage from getting worse by treating the upper surface. We would recommend cleaning the concrete extremely well and then doing a two step sealer process. The first would be a straight densifier followed by a stain guard sealer. After that you would need to fill any open contraction or expansion joints with a self-leveling polyurethane or polyurea joint filler like SikaFlex. Doing this should seal and protect the concrete well and it’s a fairly easy DIY project as long as the surface of the concrete is not very damaged.
For product, you may want to check out Garage Flooring LLC. Their TL37 and TL40 work very good together for project such as yours.
AJGSyc says
Hello! After reading your penetrating sealer post and your response to my question there, I found this page and have a question similar to one another reader posted above.
My situation is this: I have a 40 year old garage floor that is moderately pitted, is about half covered with a poor quality paint, and I’m guessing has moderate moisture issues given a musty smell that comes about in warm weather. Also, I live in a cold climate where salt use is prolific.
Would I be better off with a siliconate sealer or with a densifier with sealer in it? Thanks so much!
Shea says
Good question AJGSyc. Densifiers are reactive and work best with concrete that is in fairly good shape. The better the concrete, the better the densifier works. We must remember that densifiers are designed for floor polishing, curing new concrete, and fortifying the surface of newer concrete or concrete in fairly good shape. With a 40 year old floor with moderate pitting, chances are the densifier is not going to react as well with the concrete and not be as effective.
AJGSyc says
You are the man! Thanks so much!
Amy says
Hi, thanks for this info! I’m researching concrete and looking for the best densifier/sealer for pouring my own concrete worktops! I’m thinking this sounds great! I havnt come across one that claims it is waterproof and this being for a worktop I want it resistant to as much as I can throw at it! I like the natural look as I will be polishing for a shine… Do you know if the recommended product in a previous comment works as well when polishing to a high shine? Have you tested it against various spillages? Also how does it handle heat?
Kind regard
Amy
Shea says
Hi Amy. Densifiers alone are not sealers. That is why you can’t find one that makes the waterproof claim. A densifier sealer has siliconates added to provide the waterproofing you are looking for, but it is not designed for what you are trying to accomplish.
For what you want to do, it’s most likely best that you tackle it similar to polished concrete. You would start with a densifier and then finish with a stain guard. The stain guard is what gives the concrete its shine and provides for the waterproofing. It requires a few steps of polishing with finer and finer grit using the densifier. Once that is done, the stain guard is introduced for a final polishing with a fiber pad to give it the shine.
We recommend that you contact Justin from Garage Flooring LLC. He has a TL37 densifier and a TL40 stain guard that will do just as described. We’re not sure how much heat you want to throw at it, but Justin can contact the manufacturer if he is not sure either.
KMac says
Hello. We had a large concrete slab poured last year, and used the W.R. Meadows clear 1100 curing compound on it. The concrete has been open to the elements i.e. GA sun in the summer, and even after I pressure washed it, you can still wipe a finger and get a white residue. It is not brittle, and the finishers mechanically troweled it, or ‘burned it in’ as they put it. Can we put a densifier straight on top to help with this? We really don’t want to strip anything at this point if we can help it, all we want is to stop the white residue which I believe may be oxidation, and we are looking for a darker finish like some of the big box stores you see. Someone suggested this would work. And if so, do you recommend a certain product to achieve this? The curing compound has been on since March of 2015, if that matters. Thanks.
Shea says
Hello KMac. According to the TDS for the 1100 Clear, the membrane that holds the moisture in for the cure will chemically break down and deteriorate after 4 weeks. Most likely there is not a film at the surface. If the concrete will absorb water drops in various areas then nothing should need to be removed.
The white residue you are getting on your fingers is most likely dusting. Dusting is generally a result of the finish process and usually caused by too much bleed water. It effectively weakens the upper most surface area and causes it to dust. Sometimes this can result in a very soft surface. You can easily test it by trying to scratch it with a screw driver. Application of a densifier will help to stop dusting and increase the surface strength of the concrete providing it’s not too soft. It will not change the color however. The cement floors that you see in the home improvement centers are actually polished concrete.
We recommend to apply a straight densifier to the surface first and then follow up with a stain guard. The stain guard will actually darken the surface somewhat and can be brought to a shine with burnishing if you like. We did an article about that here. The densifier will strengthen and fill the larger pores in the concrete while the stain guard with nano technology fills the rest and provides the protection.
KMac says
Sorry, missed the response you added. Thanks. My concrete is not brittle/soft, and I have tested it in various areas with screwdriver, razors, etc, with no noticeable damage to the surface. Is there a certain product not too expensive that you recommend? I have 1944 square feet to do, so every dollar counts. Thanks again.
Shea says
We suggest contacting Garage Flooring LLC. They have a few differnet densifiers which you can find here. They are lithium based densifiers which are DIY friendly, easy to apply, and only require one application.
Ed says
Just been reading this post and it has been really informative.
We were planning to paint a newly created driveway (that is about 6+ months old) but there are dusting issues. Would you recommend applying the densifier before painting to reduce the dust or just use the penetrating sealer as mentioned above? And can the surface be painted straight after the densifier has been applied or do we need to acid etch or grind the surface first.
Shea says
Hi Ed. Are you sure you want to paint the driveway? Is your goal to change the appearance or stop the dusting? Paint would not perform well at all for a driveway (peeling, hot tire lift, yellowing, and etc.) and can make it slippery when wet. If you aren’t looking to change the appearance and just want to stop the dusting, as well as seal and protect it at the same time, then we would suggest a densifier and sealer combo like this one. It will strengthen the surface as well as make it much more resistant to staining from vehicles.
If you want to change the appearance, then a tinted acrylic sealer would be a better choice. It’s a film forming U.V. stable sealer that can be tinted to add color. It’s recommended to add an anti-slip additive for a driveway. You can see an example of this type of sealer here that is applied in clear. These are much more common for creating a decorative look for driveways.
Kelvin says
Hi Shea, I’m looking at using either PS101 from Concrete Sealers or VSeal 101 to seal a 1900 SF driveway. I’d also like to stain the concrete prior to doing that. Do you have a recommended stain that would work well with those two penetrating sealers?
Shea says
You should be able to use either one with a stain Kelvin. Keep in mind though, concrete stain looks very dull and muted when applied. It is designed to be used with a topical coating, not a penetrating sealer. The topical coatings make the stain color “pop” and stand out. A penetrating sealer will not bring out the color at all. It will still look dull and boring.
Susan gaskell says
I just had a garage floor replaced. What is the best way to seal it for Wis weather conditions?
Shea says
Hi Susan. If you just want a good sealer for bare concrete then we would recommend a siliconate sealer. It’s easy to apply and lasts for years.
CB says
I am building a new garage at my home with a pretty smooth concrete floor. I will be doing some welding and grinding in the space, so want to stay away from finishes that will be burned by sparks or slag. I am researching finishes and it sounds like a densifier may be a good solution, or possibly a siliconate penetrating sealer. I saw a 10 year estimate on life span of siliconate, how does the densifier compare and can you recommend one over the other? Thank you.
Shea says
Hello CB. A straight densifier hardens the surface of the concrete. That is what they are designed to do. The byproduct of doing that tends to help seal the surface since many of the capillaries in the concrete are being filled by the reactive process. It’s not considered a sealer however. A densifier with a siliconate sealer added densifies the concrete and helps to seal it at the very upper most surface since a small amount of the siliconate is added to the mix. This is a good combo for a garage with light traffic and a suspect surface hardness. A straight siliconate penetrating sealer will do the best at sealing the concrete while slightly increasing the surface strength. The sealer basically lasts as long as the upper layer of the concrete does since it becomes part of the concrete. Many times these last the life of the concrete. Do not get siliconate sealers confused with silicone sealers. Silicone sealers don’t last long and need to be reapplied since they sit more on the surface and can wear off quickly.
Another option that results in better oil stain resistance is this combo. You may want to read this article as well about sealers for large garages and shops.
CB says
Thank you for the reply Shea. I checked with my contractor and my floor has a machine troweled finish and was installed just 6 months ago. Preventing oil or salt stains in the garage is not a primary priority. I am most interested in what will be a long term solution to hold up best with welding sparks and grinding steel and rolling carts that will also allow for easy metal scrap clean-up with a broom.
Shea says
One thing we want to make sure you understand CB is that there isn’t a sealer or coating made that is going to protect the concrete from getting burn marks due to welding and/or hot slag from cutting torches if that is one of the requirements that you are looking for. Grinding generally is not an issue. The burn marks will not affect the performance of a penetrating sealer or densifier however.
As far as sweeping goes, a machine troweled surface is already fairly smooth and should allow for easy cleanup. Based on your requirements, a straight densifier would most likely be your best bet. It will harden the surface even more ensuring that you will always have that smooth surface. If you want the surface smoother than what you have now, your only option is to use a coating. Garage Flooring LLC has a new urethane penetrating sealer called TLPPC that you can find here. It goes on very easy an actually creates a tough thin coating. Again, hot slag and welding can burn through any coating however unless you protect it with welding blanket or something similar.
CB says
Very helpful Shea, thanks very much!
Brenda says
I am looking at the best product to use to seal a concrete slab which will also be the finished floor of our house. This will be DIY. The concrete had a colorant added when it was poured. The slab was poured about about 4 months ago and is under roof, though there is also a covered front porch. While the drainage is good, I would like to have a deep penetrating sealer that can help with water vapor and humidity, especially in the spring and summer, and make sure the floor/ house stays dryer, maybe stop possible radon ( we haven’t noticed a problem, but just in case), and I don’t want to have to reapply it. I do want to bring out the color with a matte or satin finish so may need an additional top coat as well. That could be something we touch up as scratches develop, if needed. Any suggestions?
Shea says
Hello Brenda. Was a vapor barrier installed before your concrete was poured? If so, there is no need to worry about possible moisture. In terms of sealing the concrete, you can do so with either a penetrating sealer or a topical sealer, but not both. A topical sealer will not adhere properly if a penetrating sealer has been applied first. If so, you would have to grind the surface of the concrete in order for a topical sealer to adhere. Penetrating sealers will not change the look of the concrete. A clear topical sealer on the other hand will make the color pop.
The most common of sealers to use in a home are acrylic sealers. They are easy to apply and offer great stain resistance to most household products and foods. Some people apply wax to the sealer in order to protect it from scratches. If they do get scratched up however, it’s not hard to reapply to fix the issue.
In terms of protection, the best product to use would be a clear polyurea coating. If you are doing this yourself, Nohr-S is great product and DIY friendly. Polyurea will not only seal your concrete, it will also provide for a very scratch resistant coating.
Since your question really is more of a decorative concrete issue, you may want to visit the Concrete Network as well. They specialize in information related to decorative concrete in homes.
Andrea says
Hi, we would appreciate any tips regarding our almost 60 year old house, sitting on a concrete slab.
We removed old carpet in one room, hoping to install either hard wood or tile. Under the old carpet we found old sheet linoleum, which was being pushed up by efflorescence blooms.
We took out the old lenoleum and ground the concrete surface this weekend, only to find the efflorescence powder return the very next morning.
We live in Southern California, in the middle of a historic drought, so heavy rainfall, climate issues are not a major impact here. Apparently the contractor who built the entire housing tract used substandard concrete and did not do a very good job installing it, as it has quite a few cracks, that appear to have been patched with some sort of glue/putty that we found in a few spots under the glue for the linoleum.
So, considering we do not have the funds to replace the entire concrete slab, need to fix this as a DIY project, any tips in how to go about sealing the slab so a new wood or tile floor could be installed at some point?
We have done extensive research, have heard numerous opinions, and are a bit lost…
We are hoping to finish renovation one room at a time and do most of the work ourselves …
Any advice/input is much appreciated.
Shea says
Hello Andrea. Moisture must be present in order for efflorescence to form. Water moves through the concrete and dissolves salts along the way. As it works its way to the surface it evaporates and leave behind the salt and mineral crystals (efflorescence). Moisture may have been trapped in the concrete for a long time and was only just now allowed to escaped after you pulled up the carpet and linoleum. Grinding would open up the pores and make it easier to do so – especially with the warmer weather. Either that, or you have a broken water pipe or drain under the slab causing the moisture.
More than likely you are going to need a penetrating sealer or combination of a densifier followed by a penetrating sealer to solve the issue. We recommend giving Mike from Concrete Sealers U.S.A. a call. He is extremely knowledgeable about stopping efflorescence in these situations and can recommend the proper type of product that will stop or at least significantly slow down the process.
Andrea says
Thank you so much, that explains it. It was rather disheartening to see the efflorescence return overnight.
The room had been flooded about 2 years ago – teenager left window open during a rain storm – with standing water in it while we were out of town, so it is possible this is still moisture that had been trapped and is now evaporating still? That would also explain why the linoleum glue appeared to harden and dry overnight, once the linoleum itself was removed.
How long should we leave the bare concrete exposed to dry out before attempting to seal it? Thanks for the tip to call concrete sealers, we had already been advised to stay away from regular large retail stores when buying sealers, epoxy, etc, so we will check them out!
Shea says
Yes, that is most likely the culprit Andrea. Since this is indoors, we recommend allowing the concrete to dry out for at least 48 to 72 hours. Running a small fan across the surface with the window open will help with drawing the remaining moisture out as well.
Andrea says
Perfect,thanks so much!
Shea says
You are welcome Andrea!
michael burr says
1) This is a new slab and I want to protect it from stains and ground in dirt. I don’t care about adding color, speckles or patterns so I don’t need a epoxy system. Is this the best product for this application?
2) On a brand new pour when can I apply a DENSIFIER?
3) When shopping for a DENSIFIER, what ingredients and concentrations am I looking for?
4) Can you recommend the best brand of DENSIFIER?
5) What is the difference between a Lithium Silicate Concrete Densifier and a Potassium Silicate Concrete Densifier?
Thanks
Shea says
Hello Michael and great questions. We added the 5th question from your second comment.
1) Densifiers and penetrating sealers will all help resist staining to various degrees, but they will not prevent staining. A stand alone densifier is the least effective when compared to other options while a densifier with a siliconate sealer added is better. If hardening of the concrete is not a requirement for your use, then a siliconate sealer by itself will resist staining even better. This product here uses a two step approach and is the most effective yet.
2) Most densifiers require that you wait 28 days for the concrete to cure first. Some siliconate sealers, however, can be applied within hours of the pour.
3) Lithium based densifiers are the desired choice. A solids content of approximately 18% or greater is preferable.
4) No one brand is best since many of your commercial quality densifiers are similar. What we recommend is purchasing from a vendor that specializes in flooring coatings and/or sealers. They generally carry commercial grade product and have the most knowledgeable staff. Stay away from the home improvement centers. As an example, Concrete Sealers USA has very knowledgeable staff that can help you choose which is best for you based on your needs as does Foundation Armor.
5) Lithium silicates are much easier to apply than sodium/potassium silicate densifiers and require less product for the same results. Sodium silicates can also leave a white residue on the surface which takes effort to remove. It works best in the hands of experienced installers.
Corey says
Hello Shea, I was curious if you could recommend a product that is a densifier but has the siliconate sealer added to it. I have been looking at Legacy Industrial’s HD40 or the PS103/104 from Concrete Sealers USA. Thanks
Shea says
Hi Corey. Garage Flooring LLC has their TL39, Legacy Industrial has their HD39, and for Concrete Sealers USA we recommend their PS103. These are all good product. The HD40 by Legacy Industrial does not include a siliconate sealer.
Kim cline says
Hello,I came across this site while researching how to seal a concrete slab floor. The house is an earth berm type, so it’s built on a slab, and in the summer, it gets rather damp especially one room. I would like to use a densifier/sealer (I think that’s what I would need) to hep keep dampness from seeping up through the floor. Is this what I would need? We intend to put carpet over the floor ( had water in the room a few yeArs back from soil that settled low around the foundation, but that’s been fixed) would a densifier sealer be what I need?
Thanks for any help you might have!
Kim
Shea says
Hello Kim. Actually a straight densifier may be a better choice. The sealer that is added seals the concrete from water intrusion on top of the slab, not the other way around. We recommend giving Concrete Sealers USA or Foundation Armor a call. They are experts in this field and offer commercial quality product that you cannot get at a home improvement center. They will know exactly which product would work best based on your needs.
Kim cline says
Brilliant! Thank you so much- I will do that. Thank you for your very prompt reply – it’s much appreciated
Chris says
Just purchased a new construction house and am planning to use one of these products on both my garage floor (and later add Nohr-S to garage) and driveway/walkway to front door. Is there any crazy reason NOT to seal the driveway? And I plan to call both and find out more, but are there any major differences between the PS104 and HD39? Or is there a different product I should be looking at?
Shea says
Hello Chris and great questions. Keep in mind that if you use any type of sealer/densifier on your garage floor, you will need to grind the surface before application of Nohr-S. PS104 by Concrete Sealers USA and HD39 by Legacy Industrial are both lithium concrete densifiers that have a siliconate sealer added to repel liquids. The main job of a densifier is to harden concrete. Generally this is not necessary for driveways and walkways, but it can be beneficial for concrete that sees heavy use such as a busy garage floor. If you want the best protection from the elements for your driveway and walkway, we would suggest a straight siliconate sealer. It is a penetrating sealer with a much heavier concentrate than what is added to the densifiers and it will protect your concrete for years. It would be the PS101 for Concrete Sealers USA. Legacy Industrial offers a product called Silax-Seal which is a silicate-siloxane mix. It penetrates deeper into the concrete and has a little less coverage rate as a result. Either would do well for your application. The PS104 or Hd39 would be a good solution for your garage if you want something to help protect the concrete before you eventually apply a coating. As stated earlier, it will require grinding of the concrete before application of the coating.
Chris says
Thank you, I’ll look into that for the driveway!
wayne says
need to coat my new garage floor it was poured about5 months ago should I be using HD 39 or some other product?
Shea says
Hello Wayne. HD39 is a non film forming penetrating sealer that densifies and helps to resist some staining. A coating is a film forming sealer and completely different from HD39. Epoxy is an example of a coating. How do you plan to use your garage floor and what do you want a product to do for you?