Basement external waterproofing, and external drainage membrane.

What are your choices? Sticky-back membrane. BS8102:2022 doesn't like it because it doesn't always stick and when it tears it isn't always repaired. A video on YouTube demonstrating the problems. Clay filled carpet that expands when wet. But it expands too early, before the concrete arrives, and fails badly. Waterproof paint, bitumen or asphalt applied hot or cold all over outside. paint gets damaged, Asphalt is far too expensive. Render. BS8102:2022 doesn't like single coat renders. Multi coat obviously starts getting expensive. Rubbing in a cement slurry to densify the concrete surface to reduce porosity. Probably partly repairs the damage caused by the labour adding more water when the concrete arrived. External drainage. Gravity or pumped.

We are not trying to waterproof with this membrane. Just drain any water against the basement down to the land drain. It is a lot easier and cheaper than shingle. Fix the membrane to the wall. Cover it in non-woven geotextile filter membrane, making it continuous, with overlaps is fine, from around the land drain pipe, up the wall and folded over the membrane at the tops and sides.

See the small blue block of roof batten fixed just inside the formwork to be concreted in. It is very easy to add a row of blocks where you will fix the top of the membrane. Mine is 1.9m wide, or high. The blocks remain when you strike the formwork.

My membrane is tough stuff. It doesn't damage easily been walked over or crush when backfilled against.

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