Replies

1. 
   IanDGilham | Apr 05, 2002 11:03am | #1

   It's a fairly simple procedure.

   The mix should be 4:1 sand:cement, not too wet, and the existing pointing should be raked out to a depth of about ¹/₂".

   Have a spray bottle filled with water handy and damp down the joint before you fill it, just to kill the suction a little.

   Force the sand/cement into the joint with a pointing trowel, filling it flush, and the easiest way of finishing the joint is to buy a jointer which is rubbed along the filled joint to leave it half-round indented.

   Work down row by row, filling the vertical joints first, then the bed joint.
   As you finish each row, gently brush all the crumbs of mortar from the brickwork with a soft bench-brush.

   Job done!! --- but work safe, with scaffold etc.

   "not too wet"

   Squeeze a handful of the mortar, you shouldn't be able to squeeze water from it and it should keep its shape when you open your hand.

   
   

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   Edited 4/5/2002 4:16:12 AM ET by IanG

1. 
   hacker454 | Apr 05, 2002 09:51pm | #2

   thanks for the advice,,,,maybe I can try it with out a book.  Thinking on using a small grinding wheel to get rid of the old stuff (not to deep though).................

1. 
   coonass | Apr 06, 2002 12:13am | #3

   Hacker,

   If your house was built before 1930 it probably has a lime based mortar. If you repoint with a strong portland-sand mix you may cause a lot of damage to the bricks. Take a sample of the old mortar to the brickyard and they can tell you what you need and might be able to match the color.

   KK

1. 
   Mongo | Apr 06, 2002 07:48pm | #5

   kk is on the mark in terms of replacing the type of mortar you have with similar material. It's especially important with older, soft brick. Here's an exerpt from an email I sent someone a while back about matching mortar:

   Add 1 part of muriatic acid to 5 parts water in a clear glass. You remember the old chem lab rule to add acid to water and not water to acid, right? anyhow, mix it up and add some of the old broken off mortar from your chimney. If the mortar begins to bubble vigorously that's an indication that the mortar contains a high percentage of lime. If there is minimal bubbling, portland cement may be a majority binder. How much is "vigorously?" If you're not pressed for time, make up a small marble-sized ball of lime/sand/water putty and let it dry. Then add it to the acid/water mix. That should define "vigorous."

   Regardless, let the mortar sit in the acid until it all chunks are dissolved. It may take overnight. If you end up with undissolved chunks you can add more acid. When all the mortar is dissolved, all that should be left in the bottom of the glass is sand. The lime and the portland will be dissolved by the acid, the sand won't. Dry off the sand, and that's the sand you want to match to keep the new pointwork from looking patchy next to the old. Try to match the old sand in both particle size AND color.

2. 
   hacker454 | Apr 16, 2002 03:56am | #6

   thanks for all the advice,,,,,,will start this little project soon...........

   Hacker454

2. 
   IanDGilham | Apr 06, 2002 12:19pm | #4

   Here's a link, with pictures, to someone re-pointing a chimney and step-by-step instructions