Can a fireplace make radon levels in my house worse?

Height amplifies the stack effect

A fireplace's pull on the ground grows with the height of the warm-air column above it, which is why a three-story house on a Marshall hillside can draw soil gas up from its foundation more forcefully than a low ranch would. The lowest, ground-contact level is where radon enters and where people often put a den or bedroom, so that's the floor to test. Tight mountainside lots that already complicate chimney routing and draft only add to the pressure quirks.

Damp French Broad gorge evenings keep those fires burning long, which lengthens the pull across the season.

The fix travels well up a tall house

A sealed [direct-vent gas fireplace](/services/gas-fireplace-installation) is the answer for these vertical homes because it seals combustion off from the interior entirely — it isn't participating in the house's air column, so it doesn't recruit make-up air from the slab. An open wood firebox does the opposite and does it harder the taller the home. If you want fire on an upper floor without pulling on the foundation below, sealed gas is the way to get it.

Our scope and the drive

We're about 25 minutes north through the French Broad gorge, so Marshall is an easy call. Radon sub-slab mitigation is a separate trade we don't handle; the fireplace's share is ours, permitted and pressure-tested as licensed gas work. Test the lowest level first with an inexpensive kit, then fix the mitigation and the hearth together so neither works against the other. Call (828) 545-0525.