This is a concrete driveway slab (not a structural component). Can anyone help me understand the condition in the picture? I was thinking either efflorescence or too much cream during the cure?


Did the concrete have a glossy shean to it? It seems as if it does in the pic’s. Looks like a bad application of concrete sealer.

thats a very good possibility. It only shows up along the expansion joints

If it is showing along the expansion joints it is efflorescence.
Remember the expansion joints will crack at the first sign of stress.
That joint carries the crack along a predetermined path.
Sorry best I can do.
I work with concrete.
It is typical to see Mineral salts if there is RH…
SUSPECT: EFFLORESCENCE.Water soluble salts.

Efflorescence is a common problem:in concrete and masonry block foundations. The white fuzzy stuff you see along the inside and outside of your basement wall is efflorescence. Don’t worry this annoying build up isn’t hazardous; efflorescence is simply salt and can be easily removed with efflorescence removers and other cleaning techniques. More than anything, if you see efflorescence it means you have a moisture problem and if gone untreated can cause deterioration.
Possible Cause.In our opinion A barrier to the underside of the slab was not placed.
The water is sloping towards the slab.
RECOMMEND: Cleaning the mineral salts before they become to hard to clean.
Regrade the lot so water does not go under the slab.
Sorry I am tired. Best I can do.

I see mineral salts/efflorescence, too.

Dr. Joe explains

Nice Barry.
Lime and hydrated line are not used much any more but the old schooled guys are sure in tune with its practicality.

Good info…thanks.

Mr. Lee
Look at the color and texture of concrete.
Efflorescence will be at the ends of the darker color or tinted concrete.
In your photo number one look at the lighter to darker shading.
Darker colored concrete has high RH.
Use your moisture meter on materals You wil start to notice a color difference.
You will also notice a texture difference when you get the hang of it.

Thanks much for your replies

My report would read.**
SUSPECT**: Efflorescence.
Cause and condition. There is no capillary break between the ground and the concrete slab or the perimeter. Soil contact.
Efflorescence. Mineral salts. Evaporation of absorbed water or RH leaves a residue of mineral salts that are in most natural water sources.
Clean the mineral stained area.
Water sealing. A professional licensed contractor experienced in sealing concrete
Trenching. Water control.
A landscaper or maintenance man with the ability in understanding lot drainage.
Possible remedy.
2 high to low perimeters cuts in the earth or loam on each side of the concrete drive.
A man made perimeter below the slab ( a trench ) leading lowest spots on the driveway sides too exit the wain water.
The concrete be exposed to the arrogate.
A material liner be placed inside the trench. A french drain cut in half.
A water proofing seal or material be placed in the exposed concrete.

I only install remedy on full plus home inspections ( More expensive reporting style ) or other involved inspection reports.

If not I add links to the report.