White substance coming from concrete?

[Niccole Barnes]

In my basement, there is a line of white, chalky stuff about 6 inches away from the drywall (basement is not finished) coming up from the concrete. I have scrubbed it, bleached it, etc. Could someone tell me what this could be and if I need to get a professional to fix this? Niccole.

[Rick Cantrell]

In my basement, there is a line of white, chalky stuff about 6 inches away from the drywall (basement is not finished) coming up from the concrete. I have scrubbed it, bleached it, etc. Could someone tell me what this could be and if I need to get a professional to fix this? Niccole.
Photos would help.
But what you are describing sounds like effervescence.
Effervescence is harmless itself, however it is an indication of excessive moisture, which could be a problem.

[Gunnar Alquist]

Actually, it's not effervescence, it's efflorescence. Effervescence is bubbles in a liquid, like champagne. From the Dictionary of Construction (Construction Dictionary by DictionaryOfConstruction.com (http://www.dictionaryofconstruction.com/))

efflorescenceDefinitionA whitish, powdery deposit of soluble salts carried to the surface of stone (http://www.dictionaryofconstruction.com/definition/stone.html), brick (http://www.dictionaryofconstruction.com/definition/brick.html), plaster (http://www.dictionaryofconstruction.com/definition/plaster.html), concrete (http://www.dictionaryofconstruction.com/definition/concrete.html), or mortar (http://www.dictionaryofconstruction.com/definition/mortar.html) by moisture. The moisture evaporates, leaving the residue.

Rick, I hope by correcting you, I gain a friend. :cool:

[Rick Cantrell]

Actually, it's not effervescence, it's efflorescence.

Stupid "Spell Check", it should have known which one I wanted to use.;)

Yep, your my buddy.

[Niccole Barnes]

Thank you both. I'll try and take some pictures this evening and post them.

[H.G. Watson, Sr.]

Photos would help.
But what you are describing sounds like effervescence.
Effervescence is harmless itself, however it is an indication of excessive moisture, which could be a problem.

I think Rick Cantrell meant to say that what you might be describing is:

efflorescence (chemistry),

which is the deposit that results from the process of efflorescing. Oftentimes a whitish, powdery or crystaline deposit on the surface. It is formed as mineral-rich water rises to the surface through capillary action and then evaporates. Efflorescence usually consists of gypsum, salt, or calcite. It can also refer to a "blooming" under a sealant, etc. Deteriorating work and/or improper work (never properly cured, over-wetted, etc.) can also evidence as your limited description might be interpreted.

There may have been a seam, cold joint, slab-to-footing, repair, interior drain system, crack, at the location. May also be an accumulation of anti drying agent, a sealer upon the unfinished floor (esp. poly type) "blooming", adhesive, a bonding agent applied to the subfloor (slab) not properly prepared (cleaned, acid etched and fully neutralized & dry prior to), etc. As indicated just your 'word-picture' makes it difficult to distinguish. Since you've made mention of "drywall" in the "unfinished basement" the possibility of drywall (gypsum) dust packed into a crevice now perking up might also be considered, as well as excavation dust or lime which may have been present after an excavation and below the later fill-in repair, showing up at seams or cracks.

Has there been occasions of standing or flowing water in the basement? Moist/damp rising? (duct-taping a square foot of thick (ml) poly and checking it periodically for condensation is an oft-employed first DIY-check regarding moisture migration up through a basement floor slab.

Sometimes, a dry hydrolic cement is stuffed into a "bubbling" crack by a well-intentioned DIYer/handy-type. A host of possibilities based on the limited description and the various ways it might be intrepreted.

HTH.



effervescence is to emit small bubbles of gas, as a carbonated or fermenting/ted liquid.

[H.G. Watson, Sr.]

Sorry, seems I'm a slow typer, thus, slower to post. When I prepared and began composing my post, there had been no other activity following Rick C's first reply. While doing so I checked the OPs posting history so as to more readily address "in the language of".Seems my efforts were duplicative of those with more-able fingers.

[Niccole Barnes]

Sorry, seems I'm a slow typer, thus, slower to post. When I prepared and began composing my post, there had been no other activity following Rick C's first reply. While doing so I checked the OPs posting history so as to more readily address "in the language of".Seems my efforts were duplicative of those with more-able fingers.
Either way, your response is much appreciated. There is definitely a moisture problem in the basement, especially in the area discussed. There has not been any sealant or any other product put on the floor.
The house is a walk under ranch. 3/4th's of the basement is cement blocks and the remaining 1/4 a double garage and front of the house. The front portion of the house has the 8-9 sheets of drywall. The area in question is within 3 feet from the garage door where we have had issues with water coming in during heavy rain. I'll take a picture later and see if that helps confirm what this is...thanks again everyone! Niccole

[Jeff Zehnder]

The white stuff (efflorescence) is just a symptom, what you need to look for is the cause! The outside of the home is where to look, check all downspouts and grade areas around the home. Any areas where water can delay moving away or pool near the home are an issue. Look critically at the grade, it changes over time and gardens around the home can build up and create areas for water to collect and pool instead of allowing it to run away from the home. More often than not it is either downspouts or areas that allow water to pool

[Steven Turetsky]

and where there is efflorescence there is subflorescence, which can do damage.

[Rick Cantrell]

and where there is efflorescence there is subflorescence, which can do damage.
I think it is more accurate to say:
Where there is efflorescence there COULD also be subflorescence, which is damaging.

[Steven Turetsky]

I think it is more accurate to say:
Where there is efflorescence there COULD also be subflorescence, which is damaging.

How does the efflorescence reach the surface?

Perhaps the most accurate would be... where there is efflorescence there is subflorescence, which is often damaging.

[Rick Cantrell]

How does the efflorescence reach the surface?

Perhaps the most accurate would be... where there is efflorescence there is subflorescence, which is often damaging.
Since I don't care to write a dissertation on the subject (not that I know that much about it). I'll let you explain the process.

[Claude Lawrenson]

http://alliance.la.asu.edu/rockart/NSF/RASI_Tidbit_CoatingsEfflorescence.pdf

[Steven Turetsky]

Since I don't care to write a dissertation on the subject (not that I know that much about it). I'll let you explain the process.

Actually, I mis-spoke. Your original statement was accurate and mine was not.

[Stuart Brooks]

I've seen CMU block covered in efflorescence so thick and moisture penetration going on so long that the CMU would disintegrate when probed with a screwdriver. Kind of like some old homes (200 years range) in Fredericksburg that had brick foundations were soaked with water so long that they would just go to powder when probed.

[H.G. Watson, Sr.]

Either way, your response is much appreciated. There is definitely a moisture problem in the basement, especially in the area discussed. There has not been any sealant or any other product put on the floor.
The house is a walk under ranch. 3/4th's of the basement is cement blocks and the remaining 1/4 a double garage and front of the house. The front portion of the house has the 8-9 sheets of drywall. The area in question is within 3 feet from the garage door where we have had issues with water coming in during heavy rain. I'll take a picture later and see if that helps confirm what this is...thanks again everyone! Niccole

This might also be residue and reaction with scale left behind from the surface infiltration (area in question is within 3 feet from the garage door where we have had issues with water coming in during heavy rain).

Soil salts, fertilizer/weed killer from lawn, de-icing salts, other chemical/salts residues, etc. Some of which can wreak havoc with unfinished floors. Leaks from autos such as brake fluid, corrosion inhibiters in fluids, Auto products, wash-off from corroded battery terminals, Run off from house surfaces, roof, etc. can collect copper, zinc, etc. Scores of things from garage or down-hill driveway might bring a constelltion of detergents, salts, alkali or acid to the final fluid that makes its way in then later evaporates leaving behind...??? upon the surface.

Perhaps you'll get an opportunity to post some pictures in the near future. You might also want to check the pitch to the area in question and see if it is in the run-off/drain path from the garage door infiltration after its had a chance to spread/seep and while its drying (esp. if its a crack or joint line). Perhaps salts from a treated plate from the wall separating the garage and the basement and/or living area was wetted and water from the garage door infiltration seeped under the separation wall - or washed in some joint compound dust and/or gyp.

Sure it isn't a dried area where a finishing product was spilled (liquid wax/protectorant)? Upon unfinished slab can be a 'itch to get up.

I wouldn't recommend using household bleach, it contains lye and this remains behind and active, as does the dioxin created when the chlorine and water makes contact with cellulose and other biologics.

Cleaning up my first grab is water. Next might be a mild acid such as half-water and half-distilled white vinegar. At least the vinegar/water solution will help neutralize residual lye left behind from your (hopefully well diluted 1 pt to 100 pts at least, more if concentrated laundry bleach) household bleach efforts. If there is ny chance that the residue is from a deteriorating battery (car, lawnmower, weed-eater, flashlight, etc.) the go-to is baking SODA.