Mortar joint???

[2zwudz]

  Why are block mortar joints dressed with a concaved tool that puts the nice radius in the mortar?  Is it for a nice look or does it have a function?

Thanks
Mark

[OldDog]

It's easy to do and helps shed water

[2zwudz]

  At what point do you go back and perform this, after so many block or so many rows? What are some pointers when doing this?


Thanks again and sorry for all of the questions

Mark

[Redoverfarm]

2zwudz the main reason is to "tuck" the mortar into the cavity and as OldDog said it more or less seals the edges to help with the water.  The second reason is that it makes a lot better looking job. 

In regards to when it all depends on how fast you progress.  You want to wait until the mortar firms up some or you will just start digging holes.  I would just guess as I never really time it just knew when it was ready.  I would say 30-45 min at a minimum.  If it goes too far then you can still do it but you have to use more elbow grease and you don't quite get the seal.  A good rule to go by is that when you need to mix more mortar check it.  Then you have the time to do it so your newly mixed batch will not get old while you are striking. 

Just a thought if you are doing this yourself is that you can add a little water to your mix for about the first time if it starts to dry out but do not continue doing this as it will weaken the blend.  There is a chemical reaction that has to occur and by constantly diluting you disrupt this and the strength just won't be 100 %