Converting a bathtub to a shower with a 1 1/4 inch drain
Older homes often feature 1 1/4-inch drain lines, but modern building codes require a 2-inch pipe for a new shower installation. Upgrading this line requires breaking into old cast iron plumbing, which stops homeowners from finishing their bathroom renovations without major structural work.
What people tried
Every workaround mentioned in the threads below. We haven’t tested any of them — and nobody here is claiming they worked.
- 1Cutting into the concrete to expose the main sewer line fitting, replacing old cast iron with PVC, and using specialized adapters like Fernco couplings.
- 2Reading subreddit information and posting photos of the completed work for community review
In their words
Unedited, grouped by where they were said, most upvoted first within each place, each linked to the thread it came from.
“Updating the bathroom drains in our newly purchased home.”source ↗
“Trying to get things up to code.”source ↗
“Any changes needed for when I get ready to put in the next one one? Any major concerns with the one I put in?”source ↗
“I am renovating my bathroom in my early 70’s house and am converting from a bathtub to a shower. Issue is the drain line is 1 1/4” and code says 2”.”source ↗
Where this came up
People with this problem also raised
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