I recently had my paver patio pressure washed and sealed with a penetrating sealer (Trident Seawall). The patio was pressure washed last year without issue. It looked great after the most recent wash too, but developed a brown tint/stain after the sealer was applied. Rewashing and then application of aluminum brightener (recommended by Trident) were both minimally effective. They then recommended f9 barc, which appears to have effectively cleaned the stain. Unfortunately, it also seems to have stripped the color off the edge pavers.
Any ideas on what caused the stain and if there’s anything that could effectively clean the edge pavers without stripping the color?
Circled are the test pavers that were cleaned with f9 barc. The interior pavers look back to their original color, but the edge pavers appear damaged.
I have seen sealers interact with the iron/minerals, specifically in grey pavers, and bring “rust” spots to the surface.
As far as the washed out pavers… what was the application ratio of BARC? Was it neutralized after? Did you reseal the pavers after using the BARC? Maybe try an efflorescence remover.
I believe he used the f9 barc undiluted and there was no neutralization. The pavers have not been resealed. Does resealing need to be done after using f9 barc?
I’ll try some efflorescence cleaner. Is there one you recommend that’s widely available, like at Home Depot?
Thanks for the insight! Does f9 barc damage sealer, or is the sealer that was there before the treatment still intact?
If diluted f9 barc still causes problems with those edge pavers, is there anything else that might clean the stain without causing the white discoloration?
I’m not sure if it would damage the sealer, a quick google suggests it shouldn’t, but typically BARC is used to remove staining before sealing, so I don’t know how frequent this scenario comes up.
If you want to check whether the sealer is still intact, you can pour a bit of water on the pavers where BARC was applied and see if it beads up. If it doesn’t, the sealer may have been compromised.
At this point, since the initial BARC application was so strong, I don’t think applying more, diluted or not, is going to help. The damage has likely already been done. If it had been applied per the instructions or with Trident’s direction, things might have turned out differently. From here, the options are to try an efflorescence remover, replace the affected pavers, or leave it be and see if time and weather help improve the chemical impact.
Sorry, I meant for the other pavers. He only tested the barc on the pavers that were circled. Now we’re looking for something besides the barc to try to clean the brown staining on the rest of the patio. Regular pressure washing and aluminum brighter didn’t work, and the barc created that white effect on the edge pavers (but worked well on the interior pavers). Thanks again for all your help!
Could you post a close-up photo of the brown stains?
Oxalic acid is typically the main ingredient in most rust removers, so if the staining is rust-related, it should take care of it. It might also avoid whatever component in BARC is causing the discoloration.
Sounds like this will be a bit of trial and error, so be sure to post back with well-documented results… it could be really helpful for others who run into a similar situation.
Alright, so after seeing the photo, what you’re dealing with isn’t quite what I had pictured. Below is the photo of the spotting I was referring to. It’s hard to tell for sure, but your photo looks more like residual dirt, sand, or debris that wasn’t fully rinsed off the surface before sealing.
Do you know if the contractor applied polymeric sand between the cleaning and sealing stages?
The patio was re-sanded (polymeric) last year, but the sealing got delayed by weather and wasn’t done until early this year. Another wash was done before the sealing, but no more sanding was performed.
