renovating cellar walls - lime mortar

[allott]

After some neccessary work, my cellar walls are now stripped back to gritstone and lime mortar.
In most areas the lime mortar is in fairly good condition, but a lot has chipped out with ease.

I'd like to re-point the now missing lime mortar, stabilise the existing (good condition) mortar and re-paint the walls white.

I'm wondering what the easiest and cheapest way of doing this is?

I understand PVA shouldn't be used to stabilise lime mortar. Will I need to repoint ALL the walls with lime mortar or is there a better way of stabilising it?

What lime mortar should I use. Wickes sell a cement containing lime, or should I make my own? If so where can I get lime for the mix?

For painting the walls white, I have exterior masonary paint. Will this be suitable? Will I need a primer? If so which type?

p.s. my cellar has a radiator, an extractor fan and the house is on a steep hill -i.e. nowhere near watertable.
I had some drainage problems which lead to water getting in. This has now been resolved and humidity seems to be 60 - 80% depending on weather.

Cheers

 

[ABCwarrior]

Hope this is some help I'm a conservation stonemason so can hopefully (re!)point you in the right direction.
Lime essentially comes in 3 formats in common use:
Hydrated- this is what most builders merchants use and we don't touch it. It's most common use is as a plasticiser with cement.
Non Hydraulic- formed from quicklime by adding water but it is at least 95% pure, and is not suitable for wet areas or exposed areas. This was proven beyond all doubt on the west coast of Scotland and elsewhere up here over many years trial and error. Only suitable use is dry and protected internal uses it needs to shed water and absorb CO2 to "go off". A cellar not advisable lack of ventilation, usually damp.
Hydraulic- sets in the presence of water (has been used on piers in Scotland), which is what we use on all external and exposed works. (it's less than 95% pure and it's the "pozzolans"(impurities) within it that give it this ability to go off in the wet)
I could waffle on for hours but.....
This is the place we get ours from:

http://www.stastier.co.uk/nhl/guides/ptgnhl.htm

 

[RedHerring2]

Just to add a bit more to ABCWarrior's info':
Hydraulic lime comes in three 'grades', mildly hydraulic, moderately hydraulic and emminently hydraulic.

I would suugest you try the moderately hydraulic lime for the re-pointing mortar, in your situation.

Don't use a masonry paint 'cos you'll lose all breathability retained by using lime mortar.
Use a breathable paint such as limewash.

 

[Nige F]

I can add nothing to the informative posts - but suggest , do you Need to colour the walls white? My own experience with limewash on walls was in my grandparent`s outside lavvy- the wretched stuff used to come off on your clothes all the time But as G`dad was a decorator of the true old skool - he probably made the stuff up himself from chalk he dug out of the Downs Could your walls be left bare ?