My sunroom which has been built for 15 years, the rendered wall below the windows has started to bubble in some areas of the rendered wall. This has only happened in the last 6 years approx. I have scrapped the bubbles off, used an Crown Alkali Resisting Primer , repainted with Crown Exterior Wall Paint and the problem comes back. I have been advised it may be salt in the sand which was used to make the cement render
Can anyone offer any help or advice on how to over come this problem without going to the expense of chipping off the rendering and re-plastering .
Can anyone offer any help or advice on how to over come this problem without going to the expense of chipping off the rendering and re-plastering .