Efflorescence in Cinderblock Comes Back After Washing

Reply

  #1  
Old 09-06-15, 03:18 PM
Member
Thread Starter
Join Date: Sep 2015
Location: USA
Posts: 5
Received 0 Votes on 0 Posts
Efflorescence in Cinderblock Comes Back After Washing

Hello,
One of my basement cinderblock walls had some tough efflorescence due to a down spout not being directed away from the home. I corrected that problem, and have cleaned all my walls. I am getting ready to paint them up with Drylok.
I have one stubborn wall that had some heavy efflorescence in several areas. I wire brushed all the heavy deposits off and treated the areas with vinegar. When I washed after the vinegar application and rinsed, a light coating of efflorescence remains. You can't feel these by hand, but you scan still see the light stains and I just can't seem to get rid of these. Since I have all of the heavy stuff off, it is ok to Drylok over these stains? I have scrubbed and scrubbed but can't get rid of those light stains. If I leave the vinegar on the wall without rinsing, the stains won't reappear, but I am afraid the vinegar will degrade the cinderblock. Does anyone have any suggestions as to what I can do?

Thanks in advance!
 
Sponsored Links
  #2  
Old 09-06-15, 03:27 PM
Member
Thread Starter
Join Date: Sep 2015
Location: USA
Posts: 5
Received 0 Votes on 0 Posts
Sorry, I posted in the wrong forum. This may need to be moved to the Basements, Attics and Crawl Spaces forum.
 
  #3  
Old 09-06-15, 05:04 PM
Member
Join Date: May 2015
Location: USA
Posts: 3,138
Received 1 Vote on 1 Post
You may have to use a stronger acid than vinegar on those tough areas. Drylock etch, or muriatic acid, for example. The dryloc will not bond well if you don't get it off.
 
  #4  
Old 09-06-15, 06:16 PM
Member
Thread Starter
Join Date: Sep 2015
Location: USA
Posts: 5
Received 0 Votes on 0 Posts
Thank you for your reply. After I used the straight vinegar, I did use Quikrete Efflorescence & Rust Remover, but I also had the same problem. When I rinsed the wall, the efflorescence kept coming back to the surface again. I'm running out of ideas. Not sure what to do....

Will the Drylok etch be any better than the Quikrete? I've been nervous about using muriatic acid because there is not much ventilation down there in the basement.
 
  #5  
Old 09-06-15, 06:59 PM
Member
Join Date: May 2015
Location: USA
Posts: 3,138
Received 1 Vote on 1 Post
Yeah, I'm not crazy about using acid in a basement either. I doubt the dryloc etch would be better than the quickrete stuff. It sounds like you are getting the deposit off, but the rinse water is just dissolving more salts and you get more staining.

If you've removed all the crusty flaky buildup and all you left are the faint white stains, you can probably go ahead and paint it. If when you spritz the areas with water it moistens the block and doesn't just roll off like the wall was waxed, then that should be good enough.
 
  #6  
Old 09-07-15, 03:36 AM
Forum Topic Moderator
Join Date: Mar 2005
Location: USA - N.E.Tn
Posts: 46,078
Received 120 Votes on 107 Posts
It doesn't have to be perfect to apply the Drylok. Posting a pic or two would give us a better idea of whether or not you've got it clean enough - http://www.doityourself.com/forum/el...your-post.html

btw - welcome to the forums!
 
  #7  
Old 09-07-15, 09:28 AM
XSleeper's Avatar
Group Moderator
Join Date: Dec 2004
Location: USA
Posts: 23,132
Received 194 Votes on 180 Posts
I would spritz with vinegar and let it dry then steel brush whatever comes off. No rinsing.
 
  #8  
Old 09-07-15, 05:11 PM
Member
Thread Starter
Join Date: Sep 2015
Location: USA
Posts: 5
Received 0 Votes on 0 Posts
Thank you! I will get some photos and post them here within the next day.
 
  #9  
Old 09-07-15, 05:17 PM
Member
Thread Starter
Join Date: Sep 2015
Location: USA
Posts: 5
Received 0 Votes on 0 Posts
Thanks to everyone for their suggestions! I am using 5 percent cleaning vinegar. If I leave the vinegar in and scrub, the efflorescence does not come back. It only comes back when I rinse. It is safe to leave the vinegar in the cinderblock without rinsing? Will it hurt the block? I don't have any crusty efflorescence, it's all back in the pores of the block. I have scrubbed it to the point where I cannot get any more out of the block.
 
  #10  
Old 09-07-15, 05:26 PM
XSleeper's Avatar
Group Moderator
Join Date: Dec 2004
Location: USA
Posts: 23,132
Received 194 Votes on 180 Posts
IMO, the point of using the vinegar -and leaving it on- is to netralize the high akalai content of the masonry, soil and groundwater. Hopefully the result of the vinegar application will be something neutral, with a pH around 7.
 
  #11  
Old 09-07-15, 06:18 PM
Join Date: Mar 2005
Location: USA
Posts: 6,130
Received 0 Votes on 0 Posts
Efflorescence require 2 things:

1.) Moisture within the concrete and 2.) some free lime within the concrete.

Concrete (poured or concrete block) both contain some lime due to the hydration of cement that is not always 100%, so lime is left behind. For block, there are some block that contain no free lime due to the curing process.- How old are the concrete walls?

Efflorescence occurs as the moisture in the concrete is drawn to the surface by evaporation and the lime is left behind. Scrubbing will remove the efflorescence initially. The moisture can be difficult to eliminate because it can come from below or from through faulty exterior waterproofing materials. A drain tile system (exterior, interior or both) can dramatically reduce the moisture in the concrete, but there is a lot of soil under and around the foundation walls and footings. - If the interior basement wall is painted, the paint will be blown off and bubbled by the pressure of crystallization of the efflorescence materials.

A good engineer friend of mine that is a moisture intrusion specialist says the "efflorescence on the surface is good since it does shown a pattern of moisture flow". Mother nature has a habit of evaporating excess moisture from wood, concrete and other materials

Interior coatings are not always successful, but something like Thoroseal can do a good job because it is not a paint ("Drylok" (and clones) or masonry type paints) since it forms a very dense coating that becomes a part of the concrete. - Unfortunately, it is a sloppy, messy and a lot of work and you should apply it to a wall that is misted immediately before application to get maximum effectiveness. - I guess the surface moisture gets drawn into the concrete and takes the Thoroseal with it.

If you get the moisture control working, there will not be a source of moisture to cause efflorescence. - No two situations are the same.

Dick
 
Reply

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread
Display Modes
 
Ask a Question
Question Title:
Description: