Hey everyone, I'm having a problem figuring out why I'm getting discoloration on my driveway after sealing it. I cleaned it with a 3300 PSI 2.5 GPM pressure washer and after it dried, the driveway looked great! So i wanted to seal in that look. After 24 hours, I applied the sealer with my sprayer; then, after the first couple hours I began to see random circles (from my surface cleaner), lines in other random places, and blotches of darker areas. These marking were definitely NOT there until after the seal was applied.

Does anyone have any experience with these penetrating sealers and know why only certain parts of the driveway looked "natural" and other parts look so bad?

I attached a couple pics to show what happened. The top of the first one shows the circles before it completely dried.

Any help would be greatly appreciated!

EDIT: My apologies, I think I posted in the wrong subject thread

 

Welcome to the forums!

While I have a lot of painting experience I don't have a lot of concrete driveway sealer experience. The first thing that comes to mind is the concrete may not have been dry. It can take concrete days to dry especially after pressure washing! I see marks in the concrete from the pressure washing and while they might not have been real noticeable prior to the sealer application, the sealer can magnify those marks. Uneven application of the sealer can also play a part.

 

Thank you for the reply!

I live in AZ and I gave it over 24 hours to dry but maybe I should have given it longer. Do you think it may be my weaker pressure washer and the prepping?

I don't know if I should have hired a pro to heat clean and then the marks would not have surfaced?

I completely agree with you that the sealer brought out the marks. Maybe the penetrating molecules grabbed the dirt and pulled them up? I'm just throwing out anything now lol

 

Concrete has the ability to absorb a lot of moisture, while the surface may appear dry - it may still have a lot of moisture in it.

A stouter PWer may have helped but generally you can do anything with a smaller one that you can with a bigger unit - just takes more time.

 

OK sounds good. I have a few more slabs on the other side so I'll allow a few more days of drying before sealing to see if that helps.

Thank you for the help!