The Problem
Water sitting under and around your block freezes, expands, and heaves the walls. In Colorado's climate, this destroys an undrained pit in a few seasons.
The Fix: A Drainage Sump
Before your base goes in, dig a small sump in the center — about a foot wide and a foot deep — and fill it with clean drain rock. Water collects there and percolates out instead of sitting under your pit.
Make It Standard
This is standard on every fire feature we build. It's a half-hour of work that saves a rebuild in three years.
Pro tips from the field
- If your yard has a high water table, add a perforated drain pipe from the sump to daylight instead of relying on percolation.
- Use clean ¾-inch drain rock, not crusher run — fines clog the voids you're counting on.
- Slope the patio around an in-ground pit away from the pit, not toward it.
Common questions
Do fire pits need drainage?
Yes — especially in-ground pits. Without it, water collects and freeze-thaw destroys the blockwork.
How do you drain a fire pit?
A central sump filled with clean drain rock, installed before the base, lets water percolate away.