Replies

1. 
   David_O'Connell | Nov 17, 2000 05:52am | #1

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   That white powder is efflorescence, and it is harmless. From the Latin word ``to flower,'' it is lime leached out of the mortar (usually not the bricks, which contain no lime) by water. Scrub it off with a dry, stiff-bristled brush. Or, scrub with detergent and water and rinse. Or, make a dilute solution of muriatic acid and water (1 part acid to 5 parts water -- always pour the acid into the water) and paint this on the brick. Rinse. It probably will come back, but you can't keep it from coming back.

1. 
   mark_cadioli | Nov 17, 2000 06:06am | #2

   *I must beg to differ with David....efflorescence is a leaching out of mineral salts ( from either the mortar and or the bricks ). It can be relieved to a certain extent by the addition of Barium Carbonate to the mortar at the time of laying. Either way, you seem to be getting rising damp in your basement as moisture is required to leach out the salts. kind regardsmark

1. 
   Ralph_Wicklund | Nov 17, 2000 06:32am | #3

   *mark,Would you happen to know if there is a time limit to efflorescense. What conditions would have to change for this to rather suddenly occur 25-30 years after installation. A separate problem with stucco - one of my customers.

1. 
   Jeff_J._Buck | Nov 17, 2000 07:35am | #4

   *Ralph, the way i understand it.....it the bricks had no problem before....the salts could be there forever. If it starts all of a sudden....there's moisture of some sort new to the situation. Maybe a crack up above that's letting the moistue find it's way to the brick? Not an expert.....so this advice will self destruct in 5 min. Jeff

1. 
   mark_cadioli | Nov 17, 2000 10:32am | #5

   *daer malf,snewhre in teh befudald regon of my head i no the ansar too that...uhhh...whhat was the qeust...quset...q..whta idd yuo ask?man that cake rum has somekick.

2. 
   Bob_Walker | Nov 17, 2000 02:21pm | #6

   *As Jeff mentioned, efflorescence results from moisture, and you b need to determine where that mositure is coming from.It is possible, not likely, but possible that its coming from condensation of the water vapor in the flue gases. (I say not likely because of the apparent amount.)Have it checked out; flue gases can be dangerous.Bob

3. 
   Matt_G. | Nov 17, 2000 02:55pm | #7

   *Good advice above about efflorescence. One thing to add... is it possible that moisture (rain) comming down the flue is contributing to/causing this situation? Fleu cap needed or in place?To learn more about efflorescence try the Brick Inst. of America Technical Library web site.

4. 
   Jerry | Nov 29, 2000 07:23am | #8

   *What Matt said... plus check the chimney cap (not the flue cap) for cracks allowing moisture to get between the flue and the bricks. Also check the seal between the flue and cap.Jerry

2. 
   john_mikol | Nov 29, 2000 07:23am | #9

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   Brickies, masons or anyone else in the know: My brick chimney (2'x2') is located near the center of my house. Down in the basement, from the slab up to the joists, I notice a "powdering- up" of the bricks that I've shop-vacked clean at least 4 different times in the 8 years we've been in the house. What is it and what causes it to return time and time again? I'm planning on doing an addition and now I'm thinking that I'll have to tear out this old chimney as part of the project. By the way, the house is about 45 years old. are the bricks doomed?