White chalky stuff

[colenighthawk]

Does anyone know what this suff is?
I started noticing it a few months ago at my house in Havasu.
Tries to clean it , not coming off

 

[Melloyellovector]

Efflorescence, calcium

if You have sprinklers / drip system in ground near by adjust to not hit concrete, or lower run times so moisture doesn’t reach concrete

normally if caught early washes right off. You could try vinegar

once gone you can use deck o shield, penetrating sealer that is used around pools

 

[LHC Kirby]

60/40 water vinegar - amazing how well it works

 

[paradise]

If you ask @RiverDave its snow

 

[79 HUSTLER]

If you ask @RiverDave its snow

Damn, beat me to it.

 

[COCA COLA COWBOY]

If the vinegar and water doesn't do it, dilute CLR, but be careful...it can stain.

 

[Kachina26]

Thought for sure this was a bot bumped thread.

 

[FreeBird236]

Unfortunately, it will never stop coming back every time it rains, or the ground gets wet. I can see the concrete is already starting to flake and disintegrate. Vinegar might slow the process. The cement formulation has something to do with, my patio is terrible, but the walkways barely do it.

 

[Taboma]

Unfortunately, it will never stop coming back every time it rains, or the ground gets wet. I can see the concrete is already starting to flake and disintegrate. Vinegar might slow the process. The cement formulation has something to do with, my patio is terrible, but the walkways barely do it.

I always thought it leached up from underneath when the soil got wet. On my Havasu driveway I only noticed it close to the edges where it met dirt. Or perhaps that's because it's also those areas that remain damp for longer periods

 

[FreeBird236]

I always thought it leached up from underneath when the soil got wet. On my Havasu driveway I only noticed it close to the edges where it met dirt. Or perhaps that's because it's also those areas that remain damp for longer periods

It is wicking up from the soil, but best I can tell the concrete has something to do with it also. You're right the longer it stays wet the worse it gets.
I have a place where my driveway meets the garage floor: Garage floor does it, drive way doesn't, either side of the joint.

 

[Melloyellovector]

Water, either the water has ( havasu water ) or it pulls the calcium out of the concrete mix
water evaporates calcium, salts etc do no.

the finish on concrete also contributes to the process, typically a hard trowel smooth finish closes off the pours, less voids for water to pass.
broom finish more voids, washed finish even more voids

in homes vapor barrier typically under slabs, outdoors non

clay soil if direct contact with concrete you almost guaranteed to see efflorescence

doing rock or sand base under the slab giving inches between helps significantly reduce it happening.

in places like havasu, many contractors form and pour on grade, they put pavers down on native soil. Eventually they’ll learn

in pics above the rocks even look wet, this is very likely overwatering or a broken sprinkler line between slab and planter
not an installer error, and maint error

 

[Desert Whaler]

When we used to install Saltillo Tiles late 80's to mid 90's , we'd come back the next day after grouting and sometimes there'd be white effloresence that was an inch high off the tile in places. Really trippy.