Tuck Pointing
 

So I decided I would tuck point our old fireplace without realizing what I was getting into.

There are spots that have deteriorated all the way through the fireplace, and other that seem to be doing fine. Should I just fill in the spots with caulk or mortar rather than clean out the existing mortar and using a new mix?

Our home was built in 1880, so I'm assuming I'll need to be careful about what mortar mix I'm using. Had bought a quickrete mortar but now I'm not sure if the portland cement in it would be detrimental.

Forgot the pictures.
Would you repoint this fireplace or just use a mortar caulk to fill in the deteriorated mortar at this point?




http://ed-yu.com/img/fpp4.jpg
http://ed-yu.com/img/1.jpg

Cant open your pics.

I'd never use any caulking on a fireplace.
Go get yourself a morter bag, it looks like a bag you use for doing fancy icing on a cake.
It will allow you to inject the morter into the voids.
I've always just used ready mix morter and it's worked fine.

Our home was built in 1880, so I'm assuming I'll need to be careful about what mortar mix I'm using. Had bought a quickrete mortar but now I'm not sure if the portland cement in it would be detrimental.[/quote]


Actually, portland mortar was just becoming popular in the late 19th century and had replaced lime mortar altogether somewhere around the 1920's or 30's.

And you are correct in that you should'nt mix the two mortars in the same wall (fireplace). Portland mortar is stronger, less flexable and will cause bricks to crack.

I would suggest finding someone that can identify which mortar you have before commencing repairs.