Damp problem

[vitekmonkey]

I have damp in an external ground floor wall of a 1906 terraced house. The damp was evident due to rotten skirting board and paint flaking from the wall. I've removed the affected skirting and plaster to find that there are 3 or 4 places where the mortar in the header section of the brickwork at the base of the wall is missing altogether and I can feel a draft coming in through these gaps.

There is a chemical DPC so I'm assuming the gaps in the mortar has lead to water ingress, how should I go about filling these gaps? Is mortar alone sufficient or will this simply act like a wick to any moisture?

 

[SUPERSLASHER]

Cut out old loose pointing on both the header section and perks of the brickwork and brush off. Damp down useing a fine spray. Mix up 4 building sand and 1 cement and a little pva dont have the mix to wet as it will smear the bricks. Work it well into the joints with a small tool or a rubbing iron leave for a while say 20 to 30 mins and then brush off with a soft brush.