We are really having a wonderful spring this year in Portugal. The fruit trees are in bloom, it hardly rains, the nights are not that cold, the days not that hot. In short, perfect weather for working!
Up on the scaffolding
We did not expect this. We planned to work on the roof in May because it usually rains very hard and a lot in April. So we decided to repoint the facade. Many of the old joints are cracked and therefore are leaking. Ants walk in and out and they are probably making nests inside the wall, so it needs some work.
repointing granite wall with lime-mortar
Repointing is a simple job, but very time-consuming. It takes a while before you have some dexterity, but even then you don’t do much more than a few m2 per day. First, we rake out the bad joints. We do this with a chisel and a hammer. But we also use wire brushes to get it nice and clean.
We have found a flat iron bar in our toolbox with which I can pry out the bad joints with little effort. We leave the joints that are still fine, in place. At most, we chisel them clean.
Then we can start pointing. Nuno made a lot of tests, to find the right mix and the right technique and finish.
Mortar with fine sand looks smooth, but it doesn’t point very easily. And in combination with the big granite blocks, we liked the mortar with a small grain more. More parts of lime, make the mortar stronger, but that is not necessarily better. After the tests we decided on this mix: 2 parts medium grey sand, 1 part fine sand, 1 part NHL5 lime and about 1 part water.
We like the mortar not too wet. You should be able to easily make a ‘raw meatball’ out of it.
Pointing, our way
First, we spray the wall with water. We thoroughly wet the joint that we are going to point (with an old detergent bottle). And then, just fill it. Nuno likes to push the mortar in from his hand with a small pointing iron. I push it all in with my fingers or with a pointing iron from a larger trowel or a plank.
Whatever you do, always work with good gloves. Lime burns, so in no time you’ll have skin fissures in your fingers, or worse. And always wear safety glasses, because a splash of lime mortar in your eye can seriously damage the cornea.
Portugeese words on pointing
|lime-mortar||argamassa de cal|
|to point (joints)||encher juntas|
|mix ratio||em proporção|