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Concrete basement floor finishing

I am working on finishing my basement, and as part of that I want to seal and finish the concrete floor. The house is from 1929, and the floor was put in later, likely in the 60s or 70s. I don't think there is a vapor barrier underneath, most likely.  We've ground the top of the slab to remove glue and paint, and now the aggregate is visible.  This looks really great when wet, and so we want to capture that look, while still sealing and finishing the floor so that it's smooth (or smoother).  We've decided not to add any color, so all we're looking for is the best product(s) to seal and/or harden the floor.

Finishing the grinding revealed several cracks running wall to wall through the slab, and also some nail holes and a couple bigger (~4" square, no more than 1/2" deep) spots that will all need to be filled or repaired.  Additionally, I should mention that our basement does not have big windows, and so ventilation will be very limited.

What products are recommended for:
1. Filling in the nail holes and the couple larger spots (I assume a cement based material is fine)
2. Filling in or fixing the cracks (I assume there may be some movement, so cement is not a good idea)
3. Hardening the floor (something like LITHI-TEK ® 4500?)
4. Sealing the floor (something like 
Gem-Tek 5100?)

Any tips or suggestions are greatly appreciated.
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Posted 2016-12-05T21:07:19+0000  by nicolaslbrown nicolaslbrown

Hello nicolasbrown and welcome to the Community.


Many products on the Home Depot site have accompanying installation videos.  To view a video of how to install a product, click on the smaller boxes with an arrow, located beside the photo of a product, on the Home


Cement-All is a great patching material that can be used to repair concrete from a feather edge up to 6” deep. It has great adhesive qualities without any additives required. Work fast, non-shrink and is very strong. You can use this to fill the nail holes and patch the other areas.  Solvent-based and impermeable coatings such as oil based paint and epoxy can be applied in 16 hours.  Here is the link for the installation processes.



After you have prepared the cracks for the flexible sealant by:


1.    Make sure that all surfaces are clean, structurally sound, dry and free from grease. Remove all dirt, oil, moisture, and/or old sealant.



2.    Widen crack using a chisel and hammer to at least 1/4” or an angle grinder.  Then use wire brush and vacuum to clean out debris. If crack depth exceeds 1/2” use Backer Rod to control depth.




Then apply the Ghostshield Lithi-Tex 4500.  For an exterior application this concentrated penetrating concrete sealer would be diluted using a (1 part sealer to 1 part water) ratio but in a basement application the manufacture recommends a 1 to 2 or a 1 to 3 sealer/water ratio.  The 4500 also works as a primer for your crack repair sealant.  Wait seven days.



Now it is time to fill the cracks.  Here are two types of materials for fixing the crack, Sikaflex Crack Sealant or Quikrete Polyurethane concrete crack Sealant. Both will stay flexible to allow for expansion.



3. With a utility knife, cut the tip of the nozzle at an angle to match

the size of the crack, then puncture the seal inside of the nozzle

and place the cartridge into a caulking gun.



4. Wearing safety gloves and goggles, hold the gun at an angle and

squeeze the gun handle to start the flow of sealant. One 10.1 oz.

cartridge will yield 24 linear feet of sealant in a 1/4” bead.



5. Gun sealant the length of the crack and allow sealant to level out

as necessary.



6. Clean up all tools, spills, and excess material with clean rags after

use. If necessary, use a paint thinner or other approved solvent,

such as acetone, following the solvent manufacturer’s




Now for a basement application finish coat, where moisture could possibly migrate up, Ghostshield recommends you using a water base coating like Cryli-Tx 5500.  This will be much less likely to fail.  If you have additional technical questions Ghostshield contact phone # is 855-573-8383.



Detailed installation instructions and product specifications can be found by first left clicking on the photo of any product on, then clicking on the word “specification” which is below the product’s photo.  You will find installations instructions and user guide to the right.  Read this over carefully to see if this is right for you.

Thank you for your inquiry.




Posted 2016-12-06T20:50:20+0000  by Char_HD_CHI
Thanks for the reply.  

What are the pros and cons of using the Quikrete Polyurethane concrete crack Sealant vs a self leveling version:

What about this 

Posted 2016-12-07T15:10:53+0000  by nicolaslbrown

Hello nicolaslbrown,

In your case, if you are repairing only horizontal cracks, a self-leveling product would be a better option.  Your choices will be between polyurethane sealants or Latex base sealants



Sikaflex Crack Flex is a self-leveling, one part, polyurethane sealant for permanently repairing cracks in horizontal concrete surfaces.  It can be used in cracks up to 1” wide. Its elastic technology formulation allows the sealant to remain flexible and move with the crack.  It adds density to keep the sealer from running into the crack like temporary crack filler.





Quikrete Concrete crack seal: Is latex based.  Do not apply to surfaces which will later be coated with anything other than acrylic water-based paint.

• Do not apply in cracks wider than ½” (12 mm). 




If you have further questions about the compatibility of either Sika or Quikrete products with the Ghostshield products below you will find their contact information.

Sika: 800-933-7452

Quikrete: 404-634-9100

Ghostshield: 855-573-8383



Posted 2016-12-08T14:41:43+0000  by Char_HD_CHI
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