DPM on external garage

[occy]

Hi, I plan to replace the entire bottom row of my single skin brick garage where the faces of the bricks have blown, I plan to replace these with engineering bricks.
Directly above this row is a Damp proof membrane as seen in pics.
My concern is that as I replace the bricks, (plan on doing 4 at a time leaving next 4 in place), should I, to ensure better adhesion to both layers of brick remove the membrane and add some kind of damp proof liquid to the mortar mix. I'm using blue circle ready mix mortar by the way.
Thanks in advance.........

 

[^woody^]

No, it will be OK as long as the DPC is intact.

 

[occy]

Cheers for getting back Woody, would I be doing it correctly replacing 4 bricks at a time, not putting any mortar on each end of the row of 4 until adjacent one are done?
Also do you put an even amount of mortar directly above and below the dpm? My thinking is that, with it being only single skin and as I will be going round the whole garage, doing it without the dpm in place would be a stronger job, as direct mortar to brick adhesion. Is there an additive to add to the mortar that would be as good as the plastic dpm?
Cheers..................Occy

 

[^woody^]

Yes leave the end joints empty until you do the adjacent section. And if adding DPC, likewise for the 100mm laps.

There is no additive to replace a physical DPC. Although several course of solid blue bricks and strong cement was a past method.

It won't be any stronger without a DPC. There is no real need for the same depth of mortar above and below the DPC, but it's important to fill the joints fully. I'd suggest that easiest would be a thinner joint on the bricks first, level it, put the DPC on, tamp it down, then fill the top joint. A thicker space above will allow you to get the mortar in easier.

 

[occy]

Cheers for that. Should be all set now.