Is my garage floor grind sufficient - need evaluation

[Bill_993]

Hi, I have a 20year+ concrete garage floor and want to re-seal using Ghostshield 8510 sealer. I'm open to other suggestions or products - note garage is bottom level of house so don't want any high VOC solution. I did perform a single Vaporscore calcium chloride test with results of 2.81.

I removed the old sealer from the floor using a 7" Diamabrush with hand grinder.

Attached are photos showing the floor results. Both show the old sealer/floor as dark and the floor after grinding with Diamabrush (light grey).

My principal concern is the floor after grind is very smooth - either the concrete is high PSI and/or Diamabrush doesn't rough up the concrete. The good side is there is limited grinding marks. I expect the sealer will have limited absorption - not many pores in the concrete for sealer to fill.

Does my floor look ok for applying the Ghostshield 8510 sealer?

 

[Shea]

Hi, I have a 20year+ concrete garage floor and want to re-seal using Ghostshield 8510 sealer. I'm open to other suggestions or products - note garage is bottom level of house so don't want any high VOC solution. I did perform a single Vaporscore calcium chloride test with results of 2.81.

I removed the old sealer from the floor using a 7" Diamabrush with hand grinder.

Attached are photos showing the floor results. Both show the old sealer/floor as dark and the floor after grinding with Diamabrush (light grey).

My principal concern is the floor after grind is very smooth - either the concrete is high PSI and/or Diamabrush doesn't rough up the concrete. The good side is there is limited grinding marks. I expect the sealer will have limited absorption - not many pores in the concrete for sealer to fill.

Does my floor look ok for applying the Ghostshield 8510 sealer?

A course grit grind like that for a penetrating sealer typically is not recommended. It opens up the pores too much and absorbs all the sealer, requiring multiple applications. If your concrete is really hard, you might get away with it. When you apply water droplets to the surface, does it get absorbed immediately or take a bit longer? Also, do you plan on applying a densifier before the 8510? I would highly recommend it for a surface treated with grinding.

 

[Bill_993]

Shea, thanks for the reply. Water doesn't absorb right away, takes a few minutes.

My concern was that the there isn't enough pores for the sealer, but you think otherwise.

My order of the 8510 will arrive by end of the week. My plan at this point is to test the 8510 in a 12" x 12" section, see how well it absorbs and quality of finish coat after drying. I can always re-grind off before doing the whole floor.

I can use the Ghostshield 4500 densifier first if you think best.

 

[Shea]

Shea, thanks for the reply. Water doesn't absorb right away, takes a few minutes.

My concern was that the there isn't enough pores for the sealer, but you think otherwise.

My order of the 8510 will arrive by end of the week. My plan at this point is to test the 8510 in a 12" x 12" section, see how well it absorbs and quality of finish coat after drying. I can always re-grind off before doing the whole floor.

I can use the Ghostshield 4500 densifier first if you think best.

Water does not penetrate concrete nearly as well as penetrating sealers. That is why concrete prep (other than cleaning) usually is not required. You had to remove an old sealer, so you didn't have a choice.

The fact that the slab does not turn dark and absorb the water drops immediately is a good thing for your situation. Yes, I would recommend applying the 4500 densifier first. Let it react with the concrete for a minimum of 5 days before applying the 8510. The reaction at the concrete surface with the densifier will produce Calcium Silicate Hydrate. The CHS fills some of the open pores and capillaries and makes the concrete more dense. It will also prevent the 8510 from being absorbed too deep and keep it at the subsurface where it needs to be to be most effective.

 

[Bill_993]

Shea, one final question. My other option is to apply SPGX Polyurea over the bare floor (I don't have any interest in flake or solid coating). I found this option attractive since has unlimited pot life (easy to apply). I did get a VaporTest result from single location of 2.81. I expect could be higher during the peak rain season in Seattle (March-April). My principal concern has VOCs of 250g/liter. My garage is bottom floor of my house.

Would the SPGX Polyurea product be a good option given my floor grind condition? Does SPGX Polyurea have less than 6 lbs or other limit on hydrostatic water pressure (isn't listed on the datasheet)?

Any thought on how long the VOC would take to subside?

 

[Shea]

Shea, one final question. My other option is to apply SPGX Polyurea over the bare floor (I don't have any interest in flake or solid coating). I found this option attractive since has unlimited pot life (easy to apply). I did get a VaporTest result from single location of 2.81. I expect could be higher during the peak rain season in Seattle (March-April). My principal concern has VOCs of 250g/liter. My garage is bottom floor of my house.

Would the SPGX Polyurea product be a good option given my floor grind condition? Does SPGX Polyurea have less than 6 lbs or other limit on hydrostatic water pressure (isn't listed on the datasheet)?

Any thought on how long the VOC would take to subside?

The floor would accept SPGX just fine. It stinks when first applied, but the majority of the stink quickly dissipates after the first few hours or so as it cures, providing you have good ventilation to the outside. The problem is going to be your moisture vapor content. SPGX is limited to 3 lbs, and you are just under that without being in the peak rainy season. You could be flirting with possible delamination issues at some point.

 

[Armorpoxy]

Hi, the SPGX which we make is an excellent choice for this appliation. The main difference is that Ghostshield which we also carry is a penetrating product and won't change much at all the look of the floor since it absorbs in, so the finish you grinded to will remain. The SPGX being a topical product will give a gloss finish to the floor. We suggest using the Armorgrip nonskid so it's not slippery.

Please note that since the floor seems to have been well grinded and 'opened up' it you may need a 2nd coat as the first coat may absorb in and leave an somewhat uneven finish. This is normal for an absorbant floor.

Please contact us directly at below for individual support as we do not monitor the GJ continuously. Thank you.

 

[Bill_993]

Closing out this post with my outcome.

I ended up using all Ghostshield products

- Started with Eco-Etch 1001. I wouldn't say it was necessary, but it did seem to make the concrete more consistent in color. I vacuumed the floor before using, but the process of hosing the Eco-Etch off with water, did really help in getting all the floor 100% clean.

- Next I used Lithi-Tek 4500 densifier and hardener. I mixed 4 parts water to 1 part 4500 and used a 1/4" nap roller. My concrete floor was very smooth and I believe hard (high PSI). 4/5 of the floor was the original slab, but 1/5 was re-done to fix an embedded drain pipe and this part was much easier to grind using the 7" Diamabrush with hand grinder. I had to use ~5-10 passes with the grinder on the original floor and ~2 passes on the re-worked section. Big difference in ability to grind and also the 4500 would absorb quickly on the re-worked (soft) section. Took a couple of hours for the 4500 on dry on the original (hard) section.

- I waited 6-days and applied the Ghostshield 8510 sealer. Used a 3/8" roller and applied as thick as possible. Took about 6-hours for most of the 8510 to dry, but overnight to completely dry. Used 1 gallon for 18.5x 18.5' =342 sq. ft. garage. The VOC odor of the 8510 is not good, worst than any product that I have used. Took 3/4 day to be not noticeable.

Overall the look of the concrete is un-remarkable. The 8510 dries colorless with flat finish. Does bead water forever, any moisture just sits on top for over a day until it evaporates. Overall I'm happy, if it proves easy to clean and lasts will be very happy.

Lastly highly recommend the Diamabrush grinding wheel, very easy to use and results in a smooth surface.

 

[PT Doc]

How large was the grinder that you used?

 

[Bill_993]

Makita 7 in. with the Diamabrush shroud. The Makita shroud doesn't work - interferes with the Diamabrush disc. My garage is only 18.5 x 18.5 feet, didn't take that long to grind with hand grinder.