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Posted: Sat Jan 22, 2011 12:07 pm
by Tone0101
Hello, I hope you can help me. We have a pinky/red coloured block paved drive made out of concrete pavours which is about 12 years old.
There is a telecoms box at the bottom of the drive which is approx 4 foot long x 2 foot wide and it has pinky/red moratr around it which is approx 3 inches wide.
The mortar has eroded and cracked and there are big holes in it so I want to remove the damaged mortar and repair it.

What mix should I use? I have white Potrtland Cement, sharp sand and kiln dried sand. I'm guessing here but I reckon I'm probably only looking at a bucket of mix to do the job.

How can I get the mortar a pinky / red colour to match in again? Do I use mortar dye ? If so, it seems a shame to have to shell out a few bob for such a small job and how much should I use for such a small job ?

Thanks a lot for your help. This forum and site have really helped me out before and I think it's brilliant for a very keen novice like me.

Cheers.
Tony

Posted: Sat Jan 22, 2011 1:27 pm
by lutonlagerlout
at 3 inches wide you really ought to use ballast and cement with a red dye,sadly the colour is hit and miss
LLL

Posted: Sat Jan 22, 2011 3:48 pm
by Tony McC
As you're in Lancashire, we'd use grano for this type of job. You can buy grano dust at most BMs in Lancashire/Cumbria/Cheshire/N.Wales for around 5 quid per 25kg bag.

3 parts grano to 1 part building/soft sand and 1 part cement. If each 'part' equated to one shovelful, and you then added around 5 heaped tablespoons of red powder/liquid dye to that mix, you should get a strong pink colour, but bear in mind that the colour when cured is always paler than that when wet and freshly mixed. You're going to need to double that to get a genuine red.

If the colour is super-important, make trial mixes using 300g grano to 100g sand to 100g cement. When mixed, split into five 100g batches and then add 10g of dye to the first, 20g to the second, 30g to the third....etc.

Allow to cure for at least three days and then decide which batch best suits your needs, and then make you main mix accordingly.

Posted: Sun Jan 23, 2011 12:31 am
by Tone0101
Thanks a lot for the replies - very helpful as always. What if I want to just use the sand and cement I've a;ready got and then add a bit of dye - can I get away with that? If so, what
do you reckon on the mix level? Maybe add a bit of kiln dried sand to the mix ? I know that the advice you give is always bob on and advising how to do it the right way and don't get me wrong I'm not trying to do a crap job but would doing a mortar with what I've got suffice?

Posted: Sun Jan 23, 2011 10:58 am
by lutonlagerlout
mortar that wide will fail
sooner rather than later
mix needs to be 3:1
cheers LLL

Posted: Sun Jan 23, 2011 3:50 pm
by Tony McC
As LLL says, mortar alone is too weak. Mortar is intended to keep things apart, not provide a structural surface: we use concrete (or granolithic concrete) for that.

I'm intrigued to know what benefit you think kiln dried sand would bring to a mortar mix. It's simply a clean, dry sand, nowt special other than that.

Posted: Sun Jan 23, 2011 4:50 pm
by lutonlagerlout
i believe its because the OP has a bag to hand?
LLL :)

Posted: Sun Jan 23, 2011 10:24 pm
by Tone0101
Right, I've measured it and the gap is a bit thinner - i.e. 1 and a half inches wide around the box. Don't know if that makes any difference. lutonlagerlout is right - it's because I've got a spare bag of it knocking about.