Had a job on some aggregate concrete yesterday to which the customer noticed today that there were a few white patches here and there…
So I went back to have a look… And it basically looks like these patches are cleaner / lighter than the rest of the area… Its been about 2 years since it’s been sealed… Does anyone have any ideas on why it’s only in like 3 spots and the rest is quite uniform… See photos attached…
I’m sure others will have better insight but a few thoughts. Is that area still wet or damp? Is that a low area where over time water collected and changed the color of that specific area? My “argument” would be I did the entire slab exactly the same, I didn’t section out those areas and change my process. Finally a statement, cleaning anything may reveal things you didn’t or can’t see when it’s dirty.
It hasn’t rained for about the last 12 hours… But it’s been damp and overcast as we’re in winter here in Australia…
On a very close look, Its pretty visible that’s its much lighter than the rest of the concrete, almost white… But yea I explained to him that I treated the entire area the same way…
To answer your question about it being a low area, it didn’t seem like that when I was rinsing…
I think he’s understood my process. Pre treat, wash, rinse, post treat… I did his driveway too (exposed aggregate as well) with the exact process and its perfect…
The owners plan is to seal with a clear coat… Do you guys rekon that sealing it would mask it a little? Or should I rather try with more pressure to see if I could lighten the rest out? I was only hitting it at 2000psi…
Leave alone……you didn’t cause that, probably skipped area when sealing. 2000 psi wouldn’t have done that. You’re good, hopefully new sealer and it will blend.
I’ve messaged the owner… And explained all the possibilities you guys have mentioned… Hopefully he doesn’t want me to acid wash it or something like that…
