Sealing around window - PVA?

[Hanny]

I have removed the old d&d plasterboard around the window (wetroom project being undertaken) leaving exposed conc blockwork on jambs and sill. The head is a steel lintel.

The wall and around the window will receive something like a 10mm marmox board with tiled finish.

In one upper corner of the window the block work was loose so I decided to remove the offending bits of block. (the lintel is stable!). The consequence of that is now the DPM is flapping around. I have used gorilla glue (fantastic stuff for sorting out problems) to stick the DPM back to the inside of the conc block outer wall. The next thing I need to do is re-insert my new bespoke conc blocks (they are only small cut pieces) using Wickes Patch Repair Pointing Mortar (12.5kg bag). Again, I have found this stuff great for small general work.

I can't see my mortar adhering to the plastic DPM? Do I need to PVA it? Ratio?

Same for the steel lintel, do I need to seal it before using an approved adhesive to stick the marmox board?

Thanks guys

 

[stuart45]

There's no need to use PVA on the vertical DPC, just butter up the end of the block and push it against the DPC and outer blockwork. That's how it's done on site when returning the inside skin at the inner reveals.