How to Make Limestone Mortar Mix

[@jamesowen1213]

the old stone firms mix which i was taught in the early 1970s was 7 parts stone dust /sand 5parts hydrated lime 2 parts white cement.use to be like spreading butter.

[@kevinfitzgerald14]

Thanks for the advice your 9/2/1 with white cement was perfect match

[@elleondejuda4681]

I would love to try this mixed

[@Allison-405]

Is this a mix that would work with a sandstone ? Thank you for sharing your experiences with us!

[@digitraxuk]

What mix would you use for ridge tiles fixing and pointing on a front door porch? Is that mix strong enough to stop them flying off in a British gale??

[@jimmeh213]

what mix does Peter recommend for repointing?

[@twbrkfd1733]

Use PHL 3.5 lime with 3 sand for historic buildings. PHL will set. Not NHL. Lime mortar is vapor permeable. Cement based mortar is not and will cause efflorescence in the stone/brick. PHL (pozzolain hydraulic lime [used by Romans for 2,000 years]) will set just like Portland cement mortar. In addition, this guy has the thermal issues resolved but NOT the vapor permeability. His 7-2-2-1 cement based mortar will expand and contract with the old stone, but will force water through the stone causing a leaching of minerals to the surface (efflorescence).

[@chandlerpetersen1244]

Can that PHL be used to repoint a 1900 fieldstone foundation? Thanks

[@elleondejuda4681]

Thanks, how can I use , sand , cement or hydraulic lime for 1960 house if possible?

[@gary24752]

What is the compressive strength of this mix? What would you recomment for repointing limestone foundation/walls?

[@charlescarabott7692]

I got an old farm limestone/sand stone out building thats is crumbling in the lower two or three layers of stone. I need to strengthen the wall not make it look pretty. What mix should i use? I live in hot dry climate. I dont know if that makes any difference

[@soldier-Dave]

The lime mortar must always be softer than the material you are pointing.with limestone/ sandstone use nhl 3.5

[@JM-eh2ch]

@@soldier-Dave don't you think 3.5 would cure too hard for sandstone? Personally I'd use lime putty with pozzolan or hotlime

[@teevarsenvyticanda6948]

Can you tile on old lime mortar

[@craigrayment2055]

That's a modern mix , most old stone work will be a hot mix , lime putty or a natural hydraulic lime 2,3.5,5 . It's a bit involved

[@xXxChaoticXx]

Is this how they did the pyramids?

[@User0resU-1]

Yes

[@richardgrimbleby7853]

Hmmm its not really a traditional lime mortar then

[@soldier-Dave]

NHL and cement!? No never!

[@drfc94]

Shouldn’t mix Nhl with cement

[@SuperPartridge1]

It’s not a natural hydraulic lime, it’s hydrated lime he’s using

[@michaeljamesdesign]

He's not using NHL. He's using lime hydrate.

[@daleburns7110]

Cement should be nowhere near an old stone wall……lime mortar only

[@JM-eh2ch]

Nice pointing, shame about the addition of white cement

[@michaeljamesdesign]

It's not a bad mix though. 9 sand is being very generous and sensible. It's been found that buildings with sand ratios of between 9 and 13 sand to 1 cement have done really well. The addition of the lime hydrate will mainly act as a plasticiser and there's no difference between white and grey cement but... at least it's not a 1:1:4 or 5 mix.

[@leecarbines6767]

Was really interested to watch this until I saw he was using white cement in the mix