A number of years back we had a waterproofing contractor dig our 1918 era foundation to insulate and water seal it. It was done while i was away and i had stipulated that there be 2" XPS bonded to the the wall with dimpleboard over it coming above  grade (with a capping)
The contractors, who previously had a good reputation,  put the dimpleboard against the wall and then the XPS. Neither or with came up above grade. Not wanting to get "she who must be obeyed" all riled up, I left it alone. Now the insulation has pushed out from the wall and a soft white tumerous growth has come out from under it.

Dana, in another post, mentioned water wicking UP the wall from the base. Could that be creating this issue? we are on a mostly sand base with clay way down.

I don't see how the insulation dimple board configuration could be causing the problem. We often will put insulation outside of the dimple board, we will use thin stuff just to protect the dimple board.

I think I would have used a roll-on or spray-on membrane, then the insulation, then the dimple.

Mike-

What type of foundation do you have?

It is an old very rough concrete-rubble mix. I know the guys put about 15 bags of hydraulic cement on 50ft of wall before the dimpleboard. They did put a good membrane on the cement before the dimpleboard but to me the best situation woul dhave been to seal all around the XPS, bonded to the wall and capped on top then have the dimple on the outside.

I am trying to see the rationale of doing it the other way around but I cannot see it.

I was asking because I have a house built in 1919 but with a different foundation. I have been recently looking at having the same thing done.

I presume that the hydrolic cement was used to create a flat surface for better adhesion of the dimple and xps board?

Did they go all the way down below the footers and put in a capillary break?

We are not allowed to have our rain water go into the sanitary sewer so all rain water must go into a garden or somewhere else. None the less, our weepers goes under the footings and ties in. The hydraulic cement is filling in a lot of holes and it odes make it somewhat smooth for the insulation (although, stupidly, not in my case) and dimple board.

If I were to do it over, I would liquid seal the bottom and sides of the the XPS to the wall then coat the XPS to be a better barrier, then dimple board. As it is, the insulation goes to the footings. I would have had the insulation come up 1 ft above grade and put an aluminum cap on it,  then have the deltaboard outboard of it.