[Closed] Repointing

Much better to stick like with like and use lime.

We had our place repointed earlier this year (stone clad). It had been bodged up with all kinds of rubbish in the past, but was originally lime. Some of the blocks near ground level had gone really soft and friable and I was thinking I would need to get them cut out and replaced. Within a matter of days after the pointing was redone in lime they'd gone back to being hard again! I'm guessing it was moisture that had got trapped in them and couldn't drain out again, but genuinely surprised how much of a difference it made.

no experience with pointing but I do with lime plasters and know how much of a difference they make to old buildings compared to modern materials so I'd stick with lime.

lime every time. especially if it's already in place, you're one up on most.
It's much harder to mix and apply (not too hot, not too cold, not too dry etc) but general advice is to use it to allow the stonework to breathe, rather than solid lump of cheap cement..

Our house was repointed in a lime mix, looks much nicer than using modern cement based mortar and no more difficult to use.

why do you need the inside repointing?
My understanding is that it wears with the rain so why has it worn on the inside?

It's much harder to mix

Plaster I used was definitely a lot harder and after the first attempt I followed the instructions and got a paddle mixer for the drill.

Definitely stick with lime in traditional building to maintain the breath-ability and balance in the building. Lime is also hydroscopic (think that's right) so it can take on moisture, then evaporate later.
It if is a gable end is there a chimney breast involved, beware of the old salts and tars bleaching through the wall and plaster/pointing.
Asked mentioned above [u]why [/u]is the internal needing repointed? by that try to understand what is happening or what has happened to the building.

Use Lime - wouldnt bother mixing it though, just buy from somewhere like this - http://www.limestuff.co.uk/pages/products.html

I'm guessing you are talking about the gable inside your loft space? It's a well known fact that lime mortar (like most things) degrades over time. Whether it's exposed or not. It doesn't matter what you use to re point but you will have to rake it out at least an inch deep if you want it to be a decent job.
I don't know about all this rubbish being spouted above regarding moisture and breathing blaa blaa.
Cement based mortar can be mixed in varying ways to make it as hard or as soft as you like. It needs to be water proof either way to prevent wicking. Most walls get penetrating damp when the mortar has degraded and become soft and porous.
I would look at the outside and perform repairs there before messing around on the inside. for that, it would be sympathetic to the building to use lime mortar but not essential. Again, if you dont rake out the joints deep enough moisture will penetrate and when freezing occurs push the new pointing out. You can see this time and again on older buildings that have had poor workmanship in this regard.

Thanks everyone for the advice. I really don't know why the mortar is crumbling on the inside and as I said the outside seems to be fine although it is difficult to see up close as I would have to get on the roof of an older property which is lower and next to my house but I have had a look with binoculars and it seems fine..

Lime is also hydroscopic (think that's right) so it can take on moisture, then evaporate later

The word you are looking for is Hygroscopic.
Hydroscopic means 'items viewed through a Hydroscope'

[i]why do you need the inside repointing?[/i]

the original mortar on the gable on the inside of our Victorian terrace had virtually turned to sand. If the outside hadn't been rendered I'm sure the whole wall would have collapsed. It was in a part of the roof you couldn't see without crawling behind the loft conversion walls. I just left it and hoped for the best.