Matching mortar colour

M

marsaday

MY house is red brick built in 1910. The mortar used was with lime.

Any tips on matching up the mortar for when i block up a window?

i have made a mix of 5 sand, 1 cement and 1 lime and it looks dark compared to the current mortar.

i have made a mix of 4 sand and 1 lime and it looks better, however it hasn't set yet and so i am not sure i will use this method.

what about 5 sand, 1 lime, 1/2 cement?
 
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If your house was built with lime mortar then it is best to repoint with lime mortar. A strong cement mortar can damage the brickwork over time.
The sand is a very important factor in the colour.
4/1 sand/hydrated non hydraulic lime is too weak. Recent analysis of older lime mortars has shown that most of the mixes were 1.5/1 or 2/1 sand/lime with added pozzolans making the lime slightly hydraulic.
If you want to use a cement mortar you could try a mixture of white cement with the mix. This will give a lime coloured mortar.
 
M

marsaday

oh, ok so you can buy white cement. didnt know that. i think that is the solution.

is white cement much more than normal?
 
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In the following picture, we have:

bottom left: 1 part WPC, 5 parts sharp sand (yellowish)
bottom right: 0.5 part WPC, 0.5 part OPC, 5 parts sharp sand (yellowish)
top: 1 part OPC, 5 parts plasterers sand (yellow/whiteish)


Over time, all three have gone quite a bit lighter as they've dried out, so if you make any test batches make sure you're patient with them.

Gary
 
M

marsaday

thanks, thats useful. you didnt do that for me did you ?
 
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By the way, I didn't try plasterers sand and WPC, because the experiment to that point suggested that it would come out like tooth paste!
 
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If the house is that old with a lime mortar it would be a shame to use a cement mortar with it a lime based mortar gives a far superior look and would blend a lot better with the existing. I would also stay away from places like Jewsons and Wickes as there sands are too soft for pointing unless you mix 66 - 33 sharp / soft.
 

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