What seemed like a routine staircase replacement for one homeowner turned into a mystery when they tore out the steps.
Behind them, beneath the foyer, the homeowner found what they described as "a full on void," raising immediate questions about airflow, moisture, and what was actually holding the area up.
They then went to Reddit's r/HomeImprovement forum to ask what to do about this "stair replacement surprise."
Here's what to know
In the Reddit thread, the homeowner said they hired a local masonry contractor after the risers on the front stairs started pulling away from the treads.
The original poster also added that they are the second owners of a flipped house, and that the project called for rebuilding the stairs around an existing footing.
Once demolition opened up the area beside the crawl space, the original poster asked whether the exposed cavity was normal: "Should it be completely empty like this?" The OP also included demolition photos.
TCD Picks » Quince Spotlight
💡These best-sellers from Quince deliver affordable, sustainable luxury for all
Most replies treated the hollow space as normal. A stronger warning focused on keeping the area dry and aired out, with one commenter writing, "The real concern would be moisture and ventilation," and recommending a ground moisture barrier and flashing to block water intrusion.
The OP replied to this comment, adding that there was "a window in the foyer above this but otherwise there's no ventilation."
More background
For homeowners inheriting work from an earlier renovation or a house flip, timing can be crucial. Once new stairs are installed, it becomes much harder to revisit waterproofing details or ask fundamental questions about what sits behind the finished exterior.
Although the homeowner described it as "an obvious newbie homeowner question," commenters focused less on whether to fill the space and more on understanding the construction before covering it again. In particular, they pointed to the need to confirm how the foyer is supported and how the exposed area will be protected from moisture.
As one commenter put it, "That void isn't automatically a problem, but I definitely wouldn't let them just close everything back up without explaining what's supporting the foyer and how they're waterproofing/flashing that exposed area."
A separate commenter suggested a simpler explanation, noting that some houses have a cold cellar in that location and some don't, so this home may have been built without one.
Where can I learn more?
Discoveries behind stairs, under crawl spaces, and around the yard can raise the same kinds of questions for homeowners.
• In California, one resident found a 500-pound creature living inside their crawl space.
• After years of runoff, a backyard drainage debacle left one homeowner in legal limbo.
• Near a home's entry, an uninvited guest under the door sparked fears of venomous wildlife.
Get TCD's free newsletters for easy tips, smart advice, and a chance to earn $5,000 toward home upgrades. To see more stories like this one, change your Google preferences here.
