I’m working on a home that is over 100 years old. Part of that process involves replacing the house’s worn out plumbing. The old sewer line had to be removed and replaced with new PVC pipes. Unfortunately, this left a gaping hole in the home’s concrete block foundation.

There are a number of ways to fill such a hole, and I felt that the best option would be to create a wooden guard/template. I made a form out of several pieces of scrap wood. I left a gap at the top of the form, and created a separate wood piece to seal off that section. I then used various shims to “stick” the form to basement wall. I filled the main portion with bag concrete from the top opening, and I then filled the remaining open space. Finally, I used another small wooden piece to secure that area.

After the concrete cured I removed the forms. I think that the results are good, and that the method was both superior and easier than trying to layer concrete into an open hole.

Here is the simple form that I created. You can see the shims to the left of the form.
You can see the huge gap in the foundation where the old sewer line was removed.
The form was secured using shims. Please note that the top is open. This is were I added the new concrete.
After I filled the top portion I sealed the area with the small piece of the form that I created.
After the concrete had cured I removed wooden form. I think that the results turned out well.