Yellow-ish lime mortar

[Marc]

Hello,

I've recently started doing some 'corrective' jobs on the house (1886 semi), involving bits of brickwork and repointing.

The bit I'm struggling with is getting the right mortar mix. Clear: no cement, lime based only. I've gone for NHL. But then the aggregate.. Most (but not all!) sources tell me to use sharp sand, not builders sand. The latter apparently prone to cracking.

Using sharp sand results in a very white mortar though (~1:2.5). The original mortar of the house is rather yellow and I love it. Picture attached gives an idea of it, in the flash it's even more yellow. Using (yellow) builders sand, even when only used in 30% ratio with 70% sharp sand already comes a lot closer. But I shouldn't? And no such thing as yellow sharp sand? Anyone suggestions what direction to think in?

Thanks!
Marc

 

[Itchinfilth]

You can purchase it in your desired colour pre mixed. The sand / aggregate mix colour are of the proportion to give you the desired colour when mixed with the lime in the bag. Can be more expensive doing it that way so it depends how much you have to do.

 

[Stevers]

Adding building sand to sharp sand (50/50) for pointing is good for adjusting colour and aids workability. Silver, Yellow and 'Ginger' sand is readily available here. Being up on the Mendips I might also add <3mm stone dust (grey or pink), but that's totally optional and a local thing giving more options for colour matching.

 

[Marc]

Thanks guys!

Ultimately it will be a big job, mostly pointing, so don't want to lock myself in the ready mixed option from the start. Seeing so many properties around here with supposedly still original (yellow) mortar but only been able to find red sharp sand (TP, Melbros, Wickes, Jewson) I very much wondered which trick I was missing.

Just this afternoon though I managed to source yellow sharp sand! (MKM building supplies in Rugby). Looks very promising!

Good to hear people have positive experiences with mixing in some amounts of builders sand. (Indeed I found it a bit easier to work with too). My neighbour, a builder himself, is on the page of you need to know the rules to bend them but mixing any building sand in is not among those Maybe the sharp sand I just sourced needs only 5% builders sand mixing in

Thanks again!
Marc

 

[a twig]

I used 2 builders, 1 sharp, 1 NHL for all my repointing and mortar, as did the stone masons when they re-built my chimney - all fine.

In my experience cracking usually results from things drying out too quickly, either because the substrate wasn’t properly damped down before hand, or the mortar dried out too quickly due to not being protected after application

 

[stuart45]

It also depends on the size of the joints. The larger the joint, the greater the amount of mortar required, and the more likely it is to crack. For bigger joints, such as for Chert stone walls, I normally use 2 sharp, 1 building, 1 NHL 3.5. I usually mix it for around 20 minutes to get air into the mix, and then leave it for another 20 to fatten up. Then another 5 minutes mix and it's ready.

 

[housegolem]

Another option for some bigger aggregates is plastering sand, mkm supply it as do wickes