Pointing with lime mortar

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Mobo_14

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• 8 Dec 2019

• #1

Hey guys.

What's a good sand lime mix for repointung a bit of old soft sandstone?

Also it looks like it has been built with sharp sand and lime mix is this how I should go about it?

Last question is it hydrolic or hydrated lime??

Thanks

 

StephenStephen

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• 8 Dec 2019

• #2

Not sure on the mix, but it's hydraulic (NHL) you want (not hydrated). Some purists would suggest lime putty, but I personally wouldn't use putty outdoors, but then I am a humble diyer...

 

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jackg

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• 15 Dec 2019

• #3

2:1.
1. Stone dust + 1. sharp sand + 1. NHL3.5.
You need variable aggregate sizes such as above. do not use one size ,e.g. sharp sand. Mortar will fall apart.
Ask local merchants what mix builders use.
Use a 4 or 5" angle grinder to remove old mortar, and brushes or scrapers.
maybe dampen area before pointing or use sloppy mix to reduce suction?
Wire brush off surplus in the following morning.

 

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John D v2.0

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• 17 Dec 2019

• #4

I used sharp sand I had left over from my drive with the NHL3.5, 3:1 mix
Worked ok and set well, but I'd have used a bit of building sand in with it if I did it again (diyer)
There are some good videos on youtube for lime repointing.

Our original was lime putty with sharp sand, but it had got damp and was falling out, virtually none in the perps, I scraped it out with a weeding knife!