Originally Posted By: dcrist This post was automatically imported from our archived forum.
This is my first post. I view the board quite often and I appreciate the value of the information that I am able to receive from it. Thank you all.
This week I inspected two different houses with what appears to be efflorescence. I am not sure what the cause is.
The first has a traditional (mortar) stucco exterior. Many of the weep holes along the bottom edge are blocked. There are some cracks in the walls. There are not expansion joints. The efflorescence is located in various locations around the house.
The second house has brick veneer in the area that the apparent efflorescence is located. There is what appears to be a build up of calcium in the weep holes. What could cause this build up?
Does the presence of efflorescence indicate possible moisture within the wall?
How do I best advise the buyer?
Thanks for any helr
David C.
p.s. I did try to include pictures with no success.
Originally Posted By: rrushing This post was automatically imported from our archived forum.
David,
Yes, efflorescence is due to moisture intrusion. Underground water is often the vehicle by which the salt deposits are left. Capillary attraction is the movement of a liquid through a structure or fibrous strands.
It has also been noted that the occurrence of efflorescence bears a relationship to the type of mortar used. With a particular type of brick and a certain mortar no efflorescence may occur, whereas, the same brick with different mortar may produce a wall heavily coated with salt deposits. The appearance of sodium and potassium salts (as sulfates) usually suggest portland cement mortar as the origin. The use of low alkali cement in mortar and grout will minimize efflorescence, at least from this source.
Since, for the most part, concrete masonry is somewhat porous, evaporation of the salt bearing water usually takes place before reaching the surface when exposed to a drying atmosphere. The hydroxides are converted by reaction with the carbon dioxide of the air to alkali and calcium carbonates. Efflorescence in the form of alkali chlorides and sulfates is formed when the structure is surrounded, exposed, or in contact with salt-bearing water or soil and appears as columnar or whisker-like crystals. This is why efflorescence is called 'whiskers'
Bottom line... the source of the moisture has to be abated.
Originally Posted By: Henry’s Housework This post was automatically imported from our archived forum.
Yes, efflorescence is due to moisture intrusion. It can be removed by power washing in some cases. Once dry, the surface should be sealed with a water repellent agent to prevent if from happening again. Some contractors use a product called V-seal to do this.