# Forum Home Renovation Brickwork  Repointing stuffup

## glow

I have a Federation house and the old mortar is deteriorating so i had a crack at repointing a couple of small areas at the exterior front (bay window) area. I bought some mortar from Bunnings and went to work, removing some (not all) lose old white colored mortar and then repointed. After a few days eflourescence started appearing on the grey mortar and spread to the bricks, after googling the problem I washed the effected area with a diluted mixture of hydrocloric acid and water (20 to one mix) and it seemed to work. Three days later it's back worse now, I have brushed it and that seemed to help for a day or two but now it's getting worse. Should I remove the new mortar - is there a special mortar I should be using? Any help much appreciated!

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## cherub65

You should be trying to match the existing mortar for colour at least, I doubt any pre bagged product will do that.
Mix your own test batches and leave to completely dry  before even starting to re point 
What product did you use? 
Re pointing is a tedious task and if not done well can look terrible, as I said match the mortar first

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## PeteV

> I have a Federation house and the old mortar is deteriorating so i had a crack at repointing a couple of small areas at the exterior front (bay window) area. I bought some mortar from Bunnings and went to work, removing some (not all) lose old white colored mortar and then repointed. After a few days eflourescence started appearing on the grey mortar and spread to the bricks, after googling the problem I washed the effected area with a diluted mixture of hydrocloric acid and water (20 to one mix) and it seemed to work. Three days later it's back worse now, I have brushed it and that seemed to help for a day or two but now it's getting worse. Should I remove the new mortar - is there a special mortar I should be using? Any help much appreciated!

  when it comes to efflourescence, you are better off using a solution specifically for the task... there is a product called "eff off" which works well! 
i also agree that a colour match should be done before jumping into repointing. 
hope this helps!

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## an3_bolt

Turn of the century (victorian, federation, cal bungalow) were typically built using lime mortar. 
Chances are if you use a cement mortar, it will crack up and drop out at some stage anyway. 
The lime mortar is relatively soft and sacrificial in nature. 
Lime putty is still available, if you choose that path. Something like 1 part putty/2 parts sharp sand - by volume will give you something that should be similar to existing.  
Regarding colour match - might regard some different shades of sand with trial and error to match. Scratch back your pointing to get the true colour of the cured mortar........and another possible way to match the sand is to get a sample of your mortar, mix it in some dilute hydrochloric acid to dissolve the lime, then strain through some filter paper (take appropriate safety precautions with lime and acids). Allow to dry and there is an approx sand colour to start with. This can also be a way to sample your lime to sand ratio by weight if you are into this stuff....... :Sneaktongue:  
Realistically, I think my place was probably built using a mix of clean sand and bush sand and other stuff thrown in, as the composition varies a little with foreign matter in the mortar to boot. The colour of my mortar also varies around the house. It is possible that to make a fantastically perfect job that looks the part ( as opposed to completing a maintenance task) a complete elevation may be required if the matching process can not be successful. 
Not up to speed with brick cleaning techniques - apart from the need to neutralise acid cleaners such as hydrochloric acid with something like soda ash in solution.

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## glow

Thanks for the info!

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## Black Cat

Fresh from a course on making the stuff. If you can't get lime putty then buy rock lime, ground up. Work out what the void ratio is on your sand (to do this you put a measured quantity of dry sand in a container, then add water - measuring how much goes in. An ideal void ratio is about 37% 
Then you add the rock lime to the sand in about the same ratio (the lime fills up the gaps when it slakes). Slowly add water, mixing as you go. Not too much water in one go or it may blow up in your face. When you have a nice dry mix, then pound it and it will go quite plastic. That is when you can start using it for repointing. Never add cement mortar to an old house!!! 
BTW, Pack the mortar in real tight with a finger trowel Don't even bother trying to use a larger trowel!!

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## an3_bolt

Sounds like a modified version of a hot lime mortar. 
If you are repointing, you most probably will not be making large amounts of mortar, and in doing so simply lime putty and sand mixed in a bucket with a drill and plaster mixer attachment will more than suffice. Just make sure that the lime putty is not too wet (gotta be more like firm fetta cheese) and the sand not too damp - and the end result will be a mix that is quite plastic and sticks to the trowel nicely (ie turn it upside down and it will stay on). 
Just search around for the lime putty - I did and got almost of 1T of it in one go so that I could tuckpoint the front of my house and repoint some other areas. But that is another story.........    
Regarding your mentioning of the void ratio - a practical demonstration of what you are talking about**:  Lime Mortar Experiment (Masonry Repair Pt 1) - YouTube 
A video that shows some of the points about how not to make a huge mess when repointing:  Brick Masonry Repointing 
And if you are really getting keen on this stuff - not the most efficient kiln (love to know how much was under burnt and how much was overburnt) but a quick and easy way:  DIY Lime Kiln (1 hr) Make Your Own Lime Cement in 12 hrs - YouTube 
By the way - use caution when working with lime. Eye protection and appropriate skin protection should be used. Lime burns are not very nice, and eyesight does not grow back once it is gone.

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