repairing internal render

[swsmale]

Hi - hope someone can help - I have a couple of questions. I'm renovating a bedroom with walls made of thermalite blocks covered with approx 10mm cement render and skin of plaster. in several areas theres been some loosening of the render which I've removed leaving a few holes down to the blockwork. I'm planning to get the whole lot reskimmed professionally, but my questions are:
1 - what should I use to repair/patch the render (any tips to avoid future cracking)
2 - I have some plastic trunking chased into the wall (box section stuff) to run AV cables. Do I just put the render over this or should I apply something (eg wire mesh) first? - its 40mm wide (25mm deep).
Thanks in advance

 

[1john]

You should be able to just go over the plastic trunking, a dampening down with some water and a coat of pva will help prevent the wall sucking the render dry and provide a more natural curing time.