Repointing mortar

[actiongirl5]

Hi,

I am not expert in this but I am trying to come close not match exactly but get as close to the original mortar as possible. The house was built in 1992 and since the mortar has weathered significantly on one half of the property but the other half is very sheltered and remains very much intact.

The mortar has some very fine grit in it maybe something like granite but overall I am more concerned it being a relatively close colour match and not a dogs dinner. I keep being told to use mortar dyes but generally I feel like I am going to be there all year trying to get the right combo and a friend of mine used some red dye earlier this year and felt it looks unnatural. As the house is abut 30 years old I hope the mortar colour can be achieved by mixing either of the common sand options we use in building today. Plus there homes were thrown up so I don't imagine they took too much care in mixing special coloured mortar.

The mortar looks to have a red tinge to it with a hint of very light brown. I realise mortar colour can vary with sand and even the colour of cement. If anyone has the expertise to have an idea of what sand might have been used then I would really appreciate it and it would save me a lot of time.

Thanks in advance.

Mandy

 

[aveatry]

I have tried to match mortar colour to do some repair work and I experimented with different sand colours all from band q using normal sand and then I found that sharp sand looked lighter colour which is what i needed as normal sand was too red, so I sieved the sharp sand to get the biggest grit out, I also used kiln dried sand which is very light colour and mixed that in.
So experiment with different mixes and leave to dry to compare but it does look to me like your mortar has a red dye in it

 

[Ivor Windybottom]

Kiln dried sand is no good for building, it has rounded particles which will very much weaken the mortar. Definitely don't muck about sieving sand, quarries have massive machines that do all this for you.

As far as texture goes, it's just building sand, the odd pebbly bit is normal. You don't see them at first, over the years the finer stuff weathers away and the chunks remain as they're harder wearing.

It's possibly just red building sand. B&Q stuff is this sort of colour, try buying a bag as a starting point, mix it 5:1 with cement in a bucket. Add a tiny dash of plasticiser or a few drops of washing up liquid (yeehah), slap it on a board and see how it sets. You could also give it a rub on day 2 while it's weak to see how it will look after weathering. Judge the colour against the original after a week or two. It will initially be very grey but this will fade.

It's hard to judge just from a photo but it looks like it could have some red dye in it. But start with red sand and see how it looks.

 

[stuart45]

Cut some out and stick it in a container with brick acid. This will leave you with a sample of the sand.

 

[^woody^]

That's dyed ready-mixed mortar with sand which could be from anywhere and may not be avaliable from the same quarry nowadays.

You need to knock up some trial mixes with red dye. And don't over-do the dye.

 

[aveatry]

Cut some out and stick it in a container with brick acid. This will leave you with a sample of the sand.