sandy brick mortar

I live in a 107 year old brick townhouse. Recently after removing some old drywall, I noticed that the mortar in the basement walls is very sandy. In some areas it is damp and in others it deteriorates like dust.
What may have caused this problem? What should I used to repoint the bricks?
Thanks.
John
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Redlocks wrote:

It is the nature of older mortars. I suggest that you may want to be careful about what you use to point it as some modern hard mortars do not get along well at all with older materials.
--
Joseph E. Meehan

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A lot of those bricks are fragile, and the mortar needs to be the weak link, so that cracks will appear in the mortar line rather than the bricks. So you need to be dealing with a high lime content mortar, I'll bet. I suggest learning a lot more about how and why it was done before doing or having anything done. Here's a start. http://vanity.qwestdex.com/nwmasonryrest/Page5.html http://www.sacredplaces.org/PSP-InfoClearingHouse/articles/Repointing%20Maso nry.htm
http://www2.cr.nps.gov/tps/briefs/brief02.htm http://www.historichomeworks.com/hhw/pbriefs/pb02.htm

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As Mehan suggests, I think it is rising damp and older mortar without Portland cement. Check the BIA web site Tech Notes carefully before you or a mason begins work. Again, as Mehan suggests, too much cement and not enough lime can cause long term problems. Tech Notes also has good advice for preparing mortar for easy repointing. This is based on recent personal experience. TB
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