What mortar colour?

[Bathman]

having trouble deciding on what mortar colour to choose, wondering what others think. It is bath stone and the original mortar appears to be a darkish grey/brown. I'm edging towards the light brown colour in the pic. Going to be repointing the whole house at some point so will have it all pointed in the same colour eventually

 

[billybuntus]

The lighter colour looks more like portland cement to me.

 

[Bathman]

The lighter brown is colour M/436 on this colour chart, the grey is M/G6

http://www.thelimecentre.co.uk/assets/documents/Lime_Centre_Mortar_colour_chart.pdf

 

[plasticpigeon]

Are you sure the grey pointing is original? I'd have thought a colour similar to the stone would be good.

 

[JoceAndChris]

Agree with plastic. The colour of the original pointing here is exactly the same as Bath stone. So I'd go as light and golden sandy as possible without being white!

 

[Bathman]

The pointing in the photo is a dark brown-grey and I assumed this is original based on it being used on the whole house and the poor condition - very crumbly and in need of re-pointing. There's no sign of any other pointing that could be original anywhere (although plenty of cement here and there) and based on the amount of maintenance on the rest of the house, I would be very suprised if either of the previous owners had ever got the whole house re-pointed. Looking at the other houses nearby they also have a dark mortar.

I had been planning to re-point in keeping with what I assume is the original mortar, but may now have a think about trying to match the stone itself. The only other colour pointing I have found is on the decorative string coarse, which uses a very light mortar between the very thin perp joints, as you can see in the pic below

 

[JoceAndChris]

I can see you'd want to be in keeping with the local tradition and with what you think is the original pointing. That is a bit dark for my taste but it's all a matter of personal preference.

 

[LadyArowana]

Has the stone been cleaned at some time? IIRC a lot of the houses in Bath previously looked much darker due to coal fire pollution etc which stained the Bath stone. Is it possible that the mortar had absorbed this pollution and became darker but was not originally like that?

 

[Bathman]

It possibly could have absorbed pollution but still think it was originally a dark colour; I cut a bit of mortar out to see what it was like under the surface. it is actually much greyer inside, with a slightly lighter, browner film formed on top. See pic below:

I'm taking a bit of a guess here, but I'm wondering if some of the houses used the dark mortar as a way of highlighting more decorative brickwork? I have noticed a number of houses using smaller Bath Stone blocks have dark mortar, which makes the brickwork stand out. Certainly the houses with larger standard blocks have lighter matching mortar, I suppose to give the impression that the houses are almost solid stone. You can see the brick work stands out quite well in the pic below, not sure it would have the same effect with a light mortar in a similar colour to the bricks.

Anyway, yet to make a decision, as I said will probably end up going with a ligher mortar as I can get it off the shelf, and the builders start on Monday!