Ytong Frost Damage - Drainage

Hello

I hope you can help me.

So we installed Ytong blocks that are placed directly on the floor slab (the waterproofing membrane is of course still under the blocks).
The first visible layer of blocks is below ground level, now moisture penetrated this bottom layer during winter and the Ytong crumbled.
We then removed all loose material, filled it up with concrete, plastered it again, and coated it with this black sealing compound which held exactly until the next winter, then it froze off again; the concrete did not bond with the Ytong block.

Now we have installed a drainage so that the water cannot rise so high.

What should I use to replace the chipped Ytong now and how should I plaster and seal it so that moisture does not penetrate again?

Here is a picture again for better understanding:

Thanks in advance

Best regards Mark

Hello Mark,

You built the shell structure in EL?

So we used Ytong stones that stand directly on the base slab (the welding membrane is, of course, still under the stones). The first visible stone layer is below the ground; moisture penetrated this bottom layer during winter and the Ytong crumbled.

No bituminous thick coating and perimeter insulation used?

Rhenish regards

Yes, it was EL but with professionals. The problem was not the sealing, that was okay. The problem was that the paving stones went right up to the house wall and expanded due to frost, thus penetrating the protective layer, and then moisture entered.

Hi I would fix that again, ask the building materials dealer what is suitable or directly contact the manufacturer of the stones. Then properly protect with thick bitumen coating and perimeter insulation and do not lay the pavement right up to the house wall anymore. Better to set a curb about 10 cm in front of it and carefully fill the space between the curb and the perimeter insulation with gravel, then grit, and finally pebbles or similar. Then no pavement can break through anymore. It is certainly effort, but then there is peace.

Hi yes, that's roughly how we did it now: filled with concrete, laid drainage, placed a studded membrane in front of it, and no longer laid the paving stones right up to the wall.

Now it's time to keep fingers crossed in winter, otherwise a company might have to deal with it next time.

Best regards Mark