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'Mortar' from scratch?

Posted: Wed Apr 05, 2017 9:02 am
by Hiroshima_Morphine
I've been attempting Google-Fu on this off and on for several years now to no avail, I think part of my issue may be I'm not using the right terms. So here is what I need to know-

How do you make a 'building paste' from natural, organic materials to use with stone. You know, like how the 'old timers' built ~real~ stacked stone fire places and cottages.

This will be for our building projects in AK (duh! :crazy: ), so sand will be in abundance but I'm not sure yet what other raw materials we will have available.

Learn me somethin' new, fellow ZSers!

Re: 'Mortar' from scratch?

Posted: Wed Apr 05, 2017 9:09 am
by Confucius
Lime, water and sand pretty much. Search "making lime mortar" on google...

Re: 'Mortar' from scratch?

Posted: Wed Apr 05, 2017 9:28 am
by Hiroshima_Morphine
ZS Engineering Department to the rescue!

Thanks, Confucius!

Re: 'Mortar' from scratch?

Posted: Wed Apr 05, 2017 3:52 pm
by JeeperCreeper
I know nothing first hand, but I find this topic interesting.

I do remember something about using poop as an ingredient replacement but I can't remember if it's mortar or cement or bricks.

Either way, I found this cool little website... probably more basic than you need but it broke stuff down for my dumb ole self

Never knew cement was so complicated... dang...

Re: 'Mortar' from scratch?

Posted: Wed Apr 05, 2017 4:30 pm
by 50 Mission Cap
Find a masonry supply store. They can steer you in the right direction. You want "cement" not concrete. There are several formulations - basically soft to hard. You mix the cement with sand to make mortar. The cement used for modern hard fired brick is too hard for old bricks or stone masonry.

Back in the old days all they had was lime which made a very soft mortar. This actually allowed a little movement with seasons, weather, and settling. But because it is soft the weather and especially acid rain erodes is over time. After Portland cement was invented they started adding less or more of this to the lime to make it harder.

You'll need to pick the right type for what you are doing. I have a 110 year old barn and the mortar on the outside is failing on the east side. (The west side had been pointed at some time past since this sees the weather and afternoon sun.) While re-pointing this side I found that there was a slightly harder mortar on the outside to resist weathering, but the inside mortar was straight lime - so soft you can stick a screwdriver into it. So they were frugal and used pure lime on most of the job, and faced it with slightly harder (and more expensive) mortar with a little Portland cement added in.

Without going to the barn I think I used Type M but don't quote me. Hard enough to weather well but won't break the limestones in the foundation during extreme weather especially hard freezes.

I got a stone masonry book from the library that will tell you all you need. Good luck.

Re: 'Mortar' from scratch?

Posted: Wed Apr 05, 2017 6:32 pm
by Hiroshima_Morphine
Thanks, 50 M C and JC

I found this if anyone is interested- explains the different types of hydrated lime, industry standards, strengths and recommended applications ... asonry.pdf