What should I use to fill and stabilize the space for the anchor bolts when replacing the toilet flange – epoxy or cement?
Asked by Ryan Wong 
6 months ago
Last Updated: May 20, 2024
Hey, I could use some input on what to use to fill this area. I need to secure the pipe and provide a solid base for the anchor bolts. I was considering either epoxy or cement, but I’m not sure which would be the best choice. It’s the pipe connected to my toilet, and I’m replacing the flange. The space is about 4 inches deep.
Simply use cement, nothing too elaborate.
Expressed gratitude
https://www.oatey.com/products/oatey-cast-iron-closet-flange-replacement-298848992
Another option is to look for a cast iron flange, get some Oakum, and then melt some lead.
You might want to grab some quickrete and then drill or chisel some holes or ridges to create anchor points.
After installing the flange, I recommend using liquid leveler.
Try a lead joint with a cast iron flange. It will keep it secure in its place. Then add some concrete underneath after attaching the closet bolts and using tapcons. This is the proper and most reliable method. While there are compression cast iron flanges available, they will never be as secure or effective as a leaded cast iron one.
Regarding the cast iron flange, follow the proper/original method and you’ll be fine. Which anchor bolts are you referring to?
Used the ones that secure the flange in place
Simply tightened the water closet flange bolts
Get a professional to repair it properly. Breaking the floor to fix a cracked riser is not ideal.
Fill up the gap with strong mortar. Consider using a compression flange, unless you happen to have the necessary tools and know-how to pour and seal a joint correctly. It’s not just about filling with oakum and lead. Secure the new flange with Tapcon screws. Keep it simple.