Stubborn stains on new construction vinyl siding - efflorescence?

I'm waiting to hear back from the vinyl siding manufacturer about how to deal with some stubborn stains that are on some new construction homes that I'm cleaning but wanted to check with everyone here for their advice. Usually the vinyl siding of most new construction homes I've cleaned just needs to be rinsed but there is something on the siding of a few houses that probably needs the help of chemicals and a lot of scrubbing. I want to know what the manufacturer suggests to remove it before I start trying different chemicals but has anyone seen this before?

Would this be efflorescence from the concrete or would it possibly come from crushed rock that is laid down in between the houses?

What can I tell the builder to do to stop this from happening in the future to make both of our lives easier?

Any help is greatly appreciated.

Efflorescence is a problem that occurs due to salts making their way from the surface of various masonry or brick surfaces. So it's not that.

It does look like concrete residue and will likely need acid washed to remove it.

Jeff

Thanks Jeff. I was originally thinking this problem was from pouring concrete but now I'm thinking that this dust may be coming from the landscapers dumping wheelbarrows of crushed rock in between the houses.

I think I'm going to try one of the following options once I hear back from the vinyl siding manufacturer:
- Vinegar and water mix
- mix of 1/3 cup TSP, 2/3 cup detergent, 1 gallon hot water.
- Concrete dissolver product like Sakrete or Speedy Clean
- Muriatic acid mix

Any other thoughts or suggestions? Thank you.

If you go to a mason yard you can get a bottle of spray on cement remover

Art Oliveri said:

If you go to a mason yard you can get a bottle of spray on cement remover

Click to expand...

Thanks Art. I phoned a concrete product place and they suggested speedy clean which is a concrete dissolver. After a little research it looks like sakrete is a popular product too. I will maybe phone some mason yards and see what product they recommend.