Cement render cracking

[david s]

Get some Flexible Pointing, water it down 20% and paint it on , forcing it into the cracks. It is a highly elastic high build (contains fine sand) product, designed for sealing around ridge caps on tiled roofs. Plenty of UV protection and totally water proof. Alternatively use some bathroom sealer, but make sure it has UV protection as it may not, being an indoor product. The outer shell is only a weather protection, The water will find its way out eventually, but it is a good idea to prevent it getting in first.

[ozziewaa]

Hi all

Our Pompeii oven has been going strong since 2014 providing us with many fun evenings. However, over the years I have had a problem with the render on the dome cracking. This results in the insulation getting wet and the oven losing heat. I have had to re-render once since the initial build and need to it again.

I have a brick dome, with an insulation mat on top. I have cement rendered and sealed with high-quality exterior paint. The last time I rendered the dome I added an additive to assist the render stretch.

Does anyone have any suggestions on how I can stop the periodic cracking of my dome? Any thoughts about the appropriate render mix I should be using?

With thanks

Alan