bricks and mortor turning white

Reply

  #1  
Old 01-08-01, 05:08 PM
Visiting Guest
Posts: n/a
we have a new home that is a little over one year old. the bricks and mortar are starting to turn to a chalky white color. this is happening on many of the homes in our subdivision. the mailboxes are the worst, with the steps changing also. some of the walls are starting to turn also. what causes this problem what can be done to correct the problem and keep it from happening again. we were told by the builder that the bricks are loosing moisture and to spray them with water and it will solve the problem. if that is the case why wouldn't the rain solve the problem?? we have noticed this recently could it also be caused by the cold weather we have had? thanks for your help.
 
Sponsored Links
  #2  
Old 01-10-01, 10:13 PM
Member
Join Date: Dec 2000
Posts: 1,019
The condition is the result of mineral salts being carried to the surface in the presents of water or water vapor. In addition, other compounds or elements may combine with the salts to form new compounds or minerals.

Efflorescence, white scum, and vanadium stains may appear as white chalky deposits. Efflorescence and vanadium stains may appear in other colors also.

Quickly: efflorescence is caused mainly by the mortar (lime & portland cement, & possibly the sand or water) and sometimes the brick. Simple efflorescence deposits are soluble in water (mainly a range of Calcium compounds). Those that have been modified by combination with Carbon Dioxide are slightly soluble (Dolomite and Calcite). White scum relates mainly to the mortar (portland cement), and sometimes the sand or improper cleaning. White scum salts are insoluble (a range of Silicate compounds). Vanadium stains relate to the brick and sometimes the sand used in the mortar. Vanadium is insoluble in water.

White scum and vanadium stains require chemical treatment. Consult a professional. Some of the chemicals are deadly poisons and using the wrong chemical because of a mis-diagnosis can aggravate the problem.

Controllable preventative measures include careful selection of the brick, quality and control of the mortar ingredients, and proper masonry practices. Environmental factors and service conditions are not controllable.

After the fact removal solutions include dry brushing, wetting the brick and scrubbing, pressure washing, chemical treatment, and sand blasting. Long term prevention measures include leaching excess salts from the brickwork (suggested by the builder, but not explicitly) and avoiding long durations of moisture contact.


we have a new home that is a little over one year old. the bricks and mortar are starting to turn to a chalky white color.
Efflorescence is the most common condition.

the mailboxes are the worst, with the steps changing also.
Is the brickwork in contact with wet soil, water, slush or snow?


we were told by the builder that the bricks are loosing moisture and to spray them with water and it will solve the problem. if that is the case why wouldn't the rain solve the problem??

Rain dissolves efflorescence salts but fails to flush them away. They are reabsorbed by the brickwork; then reappear when it dries. Some forms of white scum will magically disappear when the brickwork is wet and reappear when it dries. The magic is light refraction.

we have noticed this recently could it also be caused by the cold weather we have had?

Drier winter air combine with higher levels of carbon dioxide may be contributing to the problem.

Bad decisions:
I will powerwash the brickwork myself.
I will sand blast the brickwork myself.
In inexperienced hands either may permanently damage the brickwork!
I will apply chemicals without consulting a professional.
The wrong chemical or misuse of may permanently set the stains!
I will apply a sealer without consulting a professional.
The sealer may cloud, or worse, the salts will chemically combine with the sealer!

Good decision:
Weather permitting, I will leach the salts by flooding the brickwork with plain water and use a fiber scrub brush for agitation; then repeat if necessary. Efflorescence can be removed by dry brushing! White scum and vanadium stains will be unaffected.
 
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