Problem with soft grey bricks?

[SBW]

On removing the tiles form an internal wall in a small toilette, part of the rendering came away exposing the brick work below. The brick are the soft grey type which had a poor reputation in the late 50’s. As the upper courses of brickwork were in poor condition I have decided to re-lay these, then re-render. I am slightly concerned about the adhesion properties of these bricks as the old mortar lifts off in a nice clean piece leaving the bricks in a very new condition. Can someone familiar with this type of brick suggest suitable precautions if any are needed?
Thank you
Barry

 

[EB1caneyeB]

They'll be fine to re-use by the sound of it. Sounds like the pug is drying out too quick. Like the bricks are so dry that they suck all the moisture out of your mortar mix. What you could do, to combat this, is dampen the top of the bricks you're about to build on. And even dampen the bricks you're about to lay.
If you are going to re-render the bricks yourself then 'PVA' the wall before you do. This will stop the bricks sucking the Water out of your render mix and not adhering sufficiently.
I use 1 mug full of PVA to a bucket of water (builders bucket). Might pay you to paint on two coats of it. Then render.

 

[SBW]

Hi EB1caneyeB
Thanks for the information it will probably turn out to be invaluable. Even I can now understand the logic.
Thank you
Barry