Puddin' Man wrote:

Greetings,

I belong to a little brick bungalow in the midwest, built in
'54, poured-concrete foundation.

Sewer gas smell in basement is detectable, far from overwhelming.

I ran a search, considered numerous possibilities (dry trap, open
clean-out in floor drain, etc). None seem to fit. Sniffed the
bsmt. floor drain particularly carefully as sump, washer, and
AC drain the no odor.

I gotta track it down.

Any ideas?

100% safe to pour a pint or so of laundry bleach in each drain?

Thx,
Puddin'

" ... and the bees made honey in the lion's head."
- from "If I Had My Way", Blind Willie Johnson


'54, Midwest, very likely means that the house sewer under the
basement floor is clay tile. The sections never fit or seal
perfectly and, after half a century, may have settled or lost
seals otherwise. There are probably extensive voids under
the slab, giving any gas plenty of opportunity to migrate out.

Normally, the stack vent would dissipate some of it by having
a constant "breeze" flowing thru the entire system, but ?

All that said, I don't have a simple fix for it :-(
Bleach may mask it for a while.....

Jim