Sealers and breathability

[BruceMc]

I have a fresh slab poured this summer still waiting to be coated. It's a hobby garage where I expect to do a fair bit of welding and grinding, so bare concrete is preferred. I do want want to toughen up the surface, so plan to apply a densifier. I also want to minimize the long term staining from typical auto fluids.

I've read dozens and dozens of threads here and, for the vendors, I have also gone to all your sites to read up on your sealer products. One aspect I don't see addressed much is the breathability of sealers. That is, the sealer allowing water vapor to transmit while still repelling liquid. We regularly get temps to -40º (and sometimes colder) and the last thing I want to do is to seal in any moisture in the slab. The slab itself is insulated with 4" of foam but isn't heated. Any suggestions?

 

[LegacyIndustrial]

From our camp...
Any of the densifiers
HD6600MMA Sealer
HD6525MMA Sealer

Trident Seafoods uses HD6600MMA and those are cold, wet, crabby floors.

 

[Garage Flooring]

I have a fresh slab poured this summer still waiting to be coated. It's a hobby garage where I expect to do a fair bit of welding and grinding, so bare concrete is preferred. I do want want to toughen up the surface, so plan to apply a densifier. I also want to minimize the long term staining from typical auto fluids.

I've read dozens and dozens of threads here and, for the vendors, I have also gone to all your sites to read up on your sealer products. One aspect I don't see addressed much is the breathability of sealers. That is, the sealer allowing water vapor to transmit while still repelling liquid. We regularly get temps to -40º (and sometimes colder) and the last thing I want to do is to seal in any moisture in the slab. The slab itself is insulated with 4" of foam but isn't heated. Any suggestions?

As you have seen there are a lot of different opinions out there. We all work with different products. You mention grinding and welding. What about exposure to gasoline, oil, etc?

IMHO opinion, what you need to do is clean your floor and densify it with a product like TL37. That is the absolute basic starting point. The next step in the process is critical.

Your going to want to use a silane / siloxane based sealer to create a hydrophobic surface. There are several different types, depending on what we expect the floor to be used.

For a basic area that is generally kept clean, TL40 is perfect. Based on your temperature statements TL021 would provide better freeze / thaw protection. Now, if you expect the floor to be exposed to automotive fluids, we have to step up to a product specifically designed to deal with those fluids. That would be Ghostshield 8505

 

[BruceMc]

Reading through some of the technical material on densifiers, most make no mention of permeability, but some do note 'reduced permeability'. Is there a difference between types of densifiers? How slight is 'slight'?

 

[BruceMc]

I should have mentioned a couple of other things. It's a 28'x32'x6" slab with a power trowel finish. The slab was poured on 7/3 and the concrete crew got to 90%, then I think the upcoming 4th of July distracted them and they left without cutting any joints or taking any steps to cure. I worked for a summer in college on a concrete crew, so I knew enough to keep it wet and got it covered the next day in visqueen. Unfortunately, the day of the pour was hot and windy, and I have some surface crazing going on. The slab itself cracked pretty much where the control joints should have gone.

 

[Garage Flooring]

Reading through some of the technical material on densifiers, most make no mention of permeability, but some do note 'reduced permeability'. Is there a difference between types of densifiers? How slight is 'slight'?

I should have mentioned a couple of other things. It's a 28'x32'x6" slab with a power trowel finish. The slab was poured on 7/3 and the concrete crew got to 90%, then I think the upcoming 4th of July distracted them and they left without cutting any joints or taking any steps to cure. I worked for a summer in college on a concrete crew, so I knew enough to keep it wet and got it covered the next day in visqueen. Unfortunately, the day of the pour was hot and windy, and I have some surface crazing going on. The slab itself cracked pretty much where the control joints should have gone.

I'm not sure that I understand the context of your first question. Densifiers help to fill in the small voids in the concrete via a chemical reaction. In of itself a densifier will not be the right solution. You would need to combine a densifier with a filmless sealer.

Densifiers are NOT a negative side waterproofing product, but they do reduce capillary action that draws moisture through the concrete. This is a good thing. They do not stop a substrate from being able to 'breath' and they are widely used on interior and exterior concrete.

 

[LegacyIndustrial]

Reading through some of the technical material on densifiers, most make no mention of permeability, but some do note 'reduced permeability'. Is there a difference between types of densifiers? How slight is 'slight'?

Bruce:
This is quite variable. The reaction that occurs between the densifier and the lime is dependent upon the surface structure of the slab. Weak surface from too much water, less reaction.

It is safe to say that moisture vapor moving through the slab is reduced to the degree that a good treatment of densifer will help to eliminate most issues with efflorescence (salts carried to the surface via water).

The best mix of densifier/sealer is our HD40 Stainguard. Covers the densifier base and helps create a nice sheen/barrier to stains from common spills yet is still breathable.
We have had really good feedback from the members here.

 

[revamped]

Thanks for all the information from the two professionals... now one more step!
What if I want to do a rust colored stain in addition to sealing. I weld, cut, work on cars etc., but I want good and easy cleanup. The man-cave also has a bar and bath for entertaining so I plan to use the same products throughout.

What do you suggest I add to the above equation and in what order?

 

[LegacyIndustrial]

Could use concrete dye, then proceed with HD40.

http://www.legacyindustrial.net/products/concrete-stain-and-dye/concrete-dye.html


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[BlackTalon]

Your going to want to use a silane / siloxane based sealer to create a hydrophobic surface. There are several different types, depending on what we expect the floor to be used.

 

[revamped]

Could use concrete dye, then proceed with HD40.

http://www.legacyindustrial.net/products/concrete-stain-and-dye/concrete-dye.html


Does the dye give the nice rust colored swirl? I thought it just changed the color of the concrete. I am going for the look in the below pic, but more of a rust color.

 

[Radix2]

Could use concrete dye, then proceed with HD40.

http://www.legacyindustrial.net/products/concrete-stain-and-dye/concrete-dye.html


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To all the floor guys - It would be super helpful if you could create a matrix to show the pros- cons and characteristics of your products in one place.

So many of us are looking for that sealed but not painted concrete look and hopefully a less scratch and chip prone surface than a full epoxy?

Also the matrix should show the combination that is suggested if any

For example in this thread we have a rec for a HD40 - but it is not clear why that would be used vs your Nohr product...

Thanks

 

[Shea]

To all the floor guys - It would be super helpful if you could create a matrix to show the pros- cons and characteristics of your products in one place.

So many of us are looking for that sealed but not painted concrete look and hopefully a less scratch and chip prone surface than a full epoxy?

Also the matrix should show the combination that is suggested if any

For example in this thread we have a rec for a HD40 - but it is not clear why that would be used vs your Nohr product...

Thanks

One thing to keep in mind guys is that you have two basic types of sealers - penetrating and film forming (topical coating).

Penetrating sealers in most cases do not change the look of the concrete. They work by penetrating into the concrete and sealing from within. They usually lie just at the subsurface.

One of the few exceptions are stain guards such as the HD40 by Legacy. These leave a thin film on the surface that can be buffed to get a semi gloss look if the concrete surface is smooth. They do require some maintenance to retain that look. They don't really scratch unless you scratch the actual concrete and they don't chip. They are stain resistant, but they do not resist stains nearly as well as a good coating.

Topical sealers such as epoxy or Nohr-S as someone was asking, are actual coatings that are much more stain resistant and provide a host of other benefits as well. They also require (in most cases) proper surface profiling before installation. Because they are a coating however, they can be scratched or chipped. How easily or how hard depends on the quality of the coating and the work environment of the garage floor.

 

[Radix2]

One thing to keep in mind guys is that you have two basic types of sealers - penetrating and film forming (topical coating).

Penetrating sealers in most cases do not change the look of the concrete. They work by penetrating into the concrete and sealing from within. They usually lie just at the subsurface.

One of the few exceptions are stain guards such as the HD40 by Legacy. These leave a thin film on the surface that can be buffed to get a semi gloss look if the concrete surface is smooth. They do require some maintenance to retain that look. They don't really scratch unless you scratch the actual concrete and they don't chip. They are stain resistant, but they do not resist stains nearly as well as a good coating.

Topical sealers such as epoxy or Nohr-S as someone was asking, are actual coatings that are much more stain resistant and provide a host of other benefits as well. They also require (in most cases) proper surface profiling before installation. Because they are a coating however, they can be scratched or chipped. How easily or how hard depends on the quality of the coating and the work environment of the garage floor.

Thanks, that is very helpful - now of course is trying to fit the various products into those categories.

The two that have garnered a lot of attention here lately seem to be SPGX and TLPPC - which sound like HD40 in that they are penetrating, but can leave a little gloss with additional coats and or buffing...

I don't know if this actually correct or if these particular products have similar staining and durability profiles. But in my case, I am looking for one of these minimal surface film products...but would still like effective stain prevention from things like oils spills if possible.

So it would be great to have a matrix that cast all these products - or at least those form a given manufacturer into some sort of order - penetrating, surface film, stainability, etc. I know there is no free lunch with a trade off of surface film to stain impenetrability , but half the time I don't really know if I am comparing apples to apples.

 

[Shea]

Remember, even coatings have to penetrate some in order to bond correctly. They just don't penetrate very deep or sit flat on the surface. SPGX is a one part polyurea coating, similar in application to Legacy Industrial's Nohr-S coating. It's not a penetrating sealer.

TLPPC is one of the few exceptions that fills a gray area. Like HD40, it's a penetrating sealer. It's also a very low solids polyurethane that will allow you to build up a thin coating. The first coat seals, the second adds some luster and a thin film. A third coat will build it more like a coating.

Garage Flooring LLC has a matrix of sort for their own product which you can find here.

 

[Radix2]

Thanks again!!

That is a good start. I would encourage you to add to it - which products can get some color from a dye ( and which kinds of dyes are ok), how primers and top coats fit in, etc. What prep is needed, recoat/refresh capabilities...

I think the guys that explain their product lines the best will see a sales benefit from it.

 

[Shea]

Generally, coatings are the only ones that will make color pop. Dyes and stains all work fine, but they each have their own characteristics. It comes down to what you are trying to achieve.

Many times the best form of action is to call a vendor so that they can qualify you for a particular coating or sealer. This allows the vendor to give a couple of options at least. Many times people don't know what they need exactly. Good vendors will ask questions about how you plan to use your garage, what type of look are you trying to achieve, square footage, what are your budget considerations, how are your DIY skills, and etc.