Pictured are weep holes through the poured concrete basement walls
of our house.
These are above grade, and are beneath the slab level, and are filled
with dirt/mud … except for one.
This one hole I can peer into, and see under the slab!
I want to plug this one up – Fill it with dirt, rock wool, something
to plug it up. Dirt is good, as if water were to ever get under there,
it could ooze through the dirt.
Secondary to that question …
This hole also has AIR FLOW into (under) the house. Air is being
sucked into this hole. (vs no air movement, vs air blowing outward).
None of the other holes suck in air.
The air test is just a Bic grill lighter, and observing the flame.
1. A LOT … the hole sucks a lot: Pass flame in front of
hole, and the flame goes out fast.
2. SOME … the hole sucks some: Pass flame in front of the
one hole the flame bends toward the hole, but does not go
out.
3. NO airflow. Flame passing in front of a hole has no
change.
The air flow is mostly generated by the radon remediation system.
Shutting that off, there is much less air being sucked into that
weep hole. But still SOME air flow in. Even with the radon fan off, and
the house HVAC off for 10 minutes, there is SOME air flow. Maybe test
this again tomorrow with radon and hvac off for a much longer period
of time.
So … the air flow into that hole is not good …
Reduces radon remediation effectiveness.
Allows a lot of outside air (cold, hot, humid) under
the slab.
Critters … there are some larger gravel in the hole,
no sign of critters.
What could be the cause …?
Replies
Stack effect. Warm air rises, finds holes at the top of the house to leak from. Cool air is sucked in through holes in the lower level of the house.