Tuck pointing fireplace with homebrew

[slschoming]

I have a buddy who needs to do some pointing in his fireplace in his home. I was wondering if homebrew could be used or if he would be better of with a store bought fireplace mortar?

[Gulf]

The homebrew would be just fine if you have enough of the ingredients to spare. Gathering up the bulk homebrew ingredients for such a small job makes the store bought a better option. Though, most of the store bought is only rated for very thin joints. I'm fixin to do the same thing on an old fireplace and will be using the homebrew. I'm going to have to replace a few brick also. I'm guessing that regular mortar was used on this job. The joints swelled and popped large chunks of the faces of several brick.

[slschoming]

I have all the ingredients sitting around (though I'm running low on portland) so I thought I'd just give him a dry mix that he can add water to when he gets it home.

Next question: I had been using homebrew in place of regular mortar on my external stuff that doesn't need homebrew because I like / am used to the workability of it. I may run out of Portland soon but have a couple leftover bags of stucco base coat.. Can that be used in place of mortar?

[fox]

Beware of a high lime mix for decorative work as over time it can leach white residue down the face .

[Gulf]

I would take the stucco back and get a couple of bags of masonry cement.

Edit: You will like regular mortars workabillity. There will be a color difference from what you have completed so far. But, you can get pretty close by adding some masonry coloring.

[Gulf]

Also, If you so choose, the 1 part Portland/1 part lime can be replaced with 2 parts masonry cement for the remainder of your decorative brick.

[slschoming]

Also, If you so choose, the 1 part Portland/1 part lime can be replaced with 2 parts masonry cement for the remainder of your decorative brick.

In the 3:1:1:1? So I could do 3:2:1 (sand : masonry cement : fire clay) to match what I've already been doing?

When buying masonry cement does Type S vs Type N matter for this application? I would definitely rather buy a bag of masonry cement than another 80 lb bag of portland this close to the end of my build.

[Gulf]

Yes, to the 3-2-1. It will probably more closely match what you already have started on the decorative brick.

Type N would be best. The original recipe for type N is 50/50 Portland to lime. The lime in today's recipe has been mostly replaced with what the industry calls "or the equivalent". That is usually lime, crushed limestone, and some proprietary additives. There are very few, if any, small companies that will still bag the original formula.

[slschoming]

Yes, to the 3-2-1. It will probably more closely match what you already have started on the decorative brick.

Type N would be best. The original recipe for type N is 50/50 Portland to lime. The lime in today's recipe has been mostly replaced with what the industry calls "or the equivalent". That is usually lime, crushed limestone, and some proprietary additives. There are very few, if any, small companies that will still bag the original formula.

Awesome, thanks!

[Gulf]

Your welcome.

I just want to bring out for future builders that are in the planning stage and may be reading this thread that the Type-N masonry cement is not a substitute for the portland and lime in the homebrew. The "or the equivalent" for the hydrated lime in today's masonry cement is not refractory as is hydrated lime.

EDIT:

I would definitely rather buy a bag of masonry cement than another 80 lb bag of portland this close to the end of my build.

Are you sure that it was not a 94 lb bag?

[slschoming]

Are you sure that it was not a 94 lb bag?

You are correct, it was a 94 lb bag.

[Gulf]

That's great! I really did not mean to nitpick. But, over the years, there have been times when people have picked up the wrong product. The 80 lb portland (cement) just threw up a red flag for me. Bagged masonry products can get confusing to someone just starting out and may be reading this thread. I'm sure that you have a handle on this.

[slschoming]

Yeah, I had it in my head that it was 80 but I think that was the premixed bags of stucco that were 80. I was mostly just pointing out that it would be a lot of excess if I bought a whole new bag this late in the game!