Hot answers tagged patch
You can patch it with hydraulic cement similar to this type You need to carefully remove all loose material and clean the area. The cement is fast setting and expands slightly as it sets, making a tight seal. Only mix as much as you can use in a few minutes.
This part of the foundation is most likely spreading out a roof load from a sizable portion of the sunroom roof. If the soil supporting the foundation has eroded away, this will need to be rectified some time next year. For now, get a bag of ready mix mortar, the kind you just add water to, it has sand and cement already mixed in in the correct proportion. ...
If the spot is really bad, you can cut it out with a saw, and replace with doweled and glued good wood. Since you're painting, a carefully done job of this shouldn't even be visible.
What you have is a system called EIFS for short. Here is a link to get to the care and repair of this type of finish. Sto Exterior Insulation and Finish Systems (EIFS) Manuals: StoTherm EIFS Repair and Maintenance Guide
Dig out any rotted wood that you can get to. Soak the wood with wood hardener around the patch area to stabilize the rotted/deteriorated wood that you couldn't get to. Fill with bondo or wood filler in 1/4" layers until slightly bulging from the patch area. Chisel/file/sand down when the final layer is almost completely dry with a sanding block. Prime ...
Best way is to find some more of the same (or similar) material, clean out or expand the hole to make it easy to patch, cut the new material to match and glue it in. Caulk if necessary and paint to match.
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