Waterproofing a cellar

The picture below is of the fire-place area in the cellar. All of the walls (including the roof of the fireplace) have been rendered with concrete to provide a solid foundation for the waterproof coat. The bitumenous material has been applied, in three coats, and you can see the sand thrown on to the final coat which has stuck to it, providing the key for plaster to stick to. Because I am not a professional, I can afford the luxury of leaving the waterproof coat like this until there are heavy rains, when I can see if it is all working well. If its all ok, then we do the final plastering on this solid, waterproof surface.

On the inside of the fireplace dots and screeds have been run to give the two flat rails (screeds) which define a flat surface. That back wall will now have a bonding plaster applied to fill in the areas between, above and below the screeds. A straight edge can then be run along the hard screeds to scrape off surplus plaster which is proud of the plane defined by the screeds. In this way we get a perfectly flat surface. The quality of the surface is probably not good but that is not important - the finishing coat will fix that. What is important is that the surface defines a flat plane so that when the finish is applied we will get a perfectly flat surface with a good quality finish.