Why not to use cement for re-pointing
Natural Lime has been used for over a thousand years in the U.K.
If your building is more than seventy years old then it is almost certainly constructed using lime. Brick or stone your building is better off being repointed with lime because:
1. Lime Mortar looks far better! If you repointed using grey cement your old building would look like a new build.
2. Lime Mortar will make the stone or brick last longer! Cement accelerates the rate of masonry decay.
3. Lime Mortar is flexible, if there are any very small movements in the building then the pointing will not
crack and fall out like hard cement will.
4. Natural Lime is far more environmentally friendly to produce than cement, its production makes far C02 and actully absorbs CO2 when it sets .
5. Lime mortar is breathable- therefore it will help to protect your building against damp.
The use of cement in buildings is one of the main causes of damp problems.
Cement mortars are often far harder and more durable than the surrounding stone. As you can see from this image this is not a good thing.
This often leads to the stone eroding faster than the mortar. This effect is not only unsightly but it also leads to increasederosion of your stone or brick work
Cement is often a grey or black colour
For many hundreds of years mortars have always been a lighter shade than the surrounding stone or brickwork never darker.
This is simply because dark pointing looks ugly
Cements mortars are often grey and ugly.
If the mortar its grey and the stone is grey then the result does not look good especially when combined with ribbon pointing
This wall has been pointed with coloured cement. Because the builders have made the colour of the mortar match the colour of the stone the stones are undefined and the wall looks flat and lifeless
The builder has tried to imitate traditional lime with colored cement. The builder has used a bush to reveal the colored aggregates in the mortar as it set unfortunately due to the hardness of cement these brush marks will never go away.
To find out more about Lime follow the links below:
http://www.buildinglimesforum.org.uk/whyuselime.htm