Help for lime pointing

[garob]

I am new to using lime and I would like to know what type of sharp sand should I use in my mix with lime?
I will be using a mix of 2 Lime and 5 Sharp sand, is this correct for pointing?
At present I have sharp sand and it is red in colour when dry and pink when mixed with the lime.
Thanks for any help !!
Gareth

 

[Jon Maine]

You are definately on the correct lines, I have tended to use 3 - 1 succesfuly for pointing although 2.5 will not be to strong.

Regarding the colour, that is up to your preference whilst trying to match existing or local tradition.

Sharp sand would benefit if it contained some bulky components too ranging up to say 5 or 6 mm, especially when using in wide joints to help give the material strength and help it resist shrinkage.

You need the temperature above 5 degrees too.

 

[Pford75]

I would always try to use local sand, since this will increase the chances of matching existing pointing.

I have always used washed sharp sand, but don't know if there is any material difference.

I can speak from experience that pointing in this weather is not a good idea.....best wait for it to warm up a bit

 

[middi]

One of the beauty about using lime is that you cannot make a mistake with the mix if you put too much in it.

If you want a nice "white" limey look use "washed" sharp sand, all those bigger black and grey particles contrasts beautifully against the whiter background. For an "aged" finish point level with the masonary, but a day or two later rub the joints with a soft wire brush, this will expose those larger particles within the mortar giving the look of many years of smaller particles washed away and erosion .

Do not use lime when frosty or prospects of frosty nights ahead.

One of the reasons for using washed sharp sand is mainly to imitate the existing " white" look of the existing mortar ( especially on dry sunny days). Originally they would not have used washed sand, but the " mud-dirt" of the unwashed sand would have been washed away from the surface over the decades resulting in that white lime look. All you are doing by using washed sand is speed up the process resulting in an immediate "look"

 

[biffvernon]

I have always used washed sharp sand, but don't know if there is any material difference.

Washed might be more expensive but it is of no advantage for lime pointing. In fact an unwashed sand that contains a substantial proportion of fine material could produce a stronger mortar and/or need less lime.

 

[garob]

Thank you to all the answers that I have received, I should of mentioned that I am pointing brick & stone in a hearth and on a chimney breast. What type of mix and sharp sand should I use ?
thanks
Gareth
North Wales

 

[middi]

As a rule of thumb 2.5 to 1 ( sharp sand/hydrate dlime) will be fine. A bit more or a bit less lime is not a problem with what you are trying to achieve.

When one considers that some chimney breasts were built using just sivved sub soil and water as mortar and are still standing I should,t worry too much about your pointing

 

[garob]

Thanks
Gareth