Many older homes in York and the surrounding boroughs sit on fieldstone or rubble stone foundations. These walls are full of joints and gaps that soil gas can move through, and the floors are often thin or uneven. We connect homeowners with a local contractor who designs a radon system around the realities of an older stone basement.
Why Stone Foundations Are Different
A stone foundation is built from irregular stones set in mortar. Over the years, mortar wears away and gaps open up between stones. Each gap is a possible path for radon. Unlike a poured wall, there is no smooth surface to seal, and the wall itself can leak soil gas along its whole length.
The floor matters too. Some older basements have a thin concrete floor poured over dirt, sometimes without a gravel layer underneath. Others have a mix of old and newer concrete, or a section of dirt floor in a back corner. Air may not move easily under that kind of floor, which affects how many suction points are needed.
None of this means the house cannot be fixed. It means the system has to be designed for the house rather than copied from a newer home.
Designing the System
The contractor starts by checking how air moves under the floor. Small test holes and a vacuum help show whether one suction point can reach the whole slab or whether more are needed. Thin or patchy floors often need extra suction points spread across the basement.
If part of the basement has a dirt floor, a membrane may be laid there and tied into the same system. Sumps, drains, and large openings in the floor are sealed.
The stone walls themselves are hard to seal completely. The goal is to create strong suction under the floor so soil gas is pulled away from the house before it can work through the walls. The contractor may also seal the largest wall gaps near the floor where they help the suction most.
What to Expect on Install Day
Older basements can be cramped, with low ceilings, old pipes, and stored belongings. Clear the areas where the contractor will drill and run pipe before install day, and point out anything fragile.
Drilling through an old floor can produce dust and loose material. Expect the contractor to control dust at the drill and clean up the work area. If the floor is very thin or cracked, they may reinforce the area around the suction point.
The pipe route in an older home often runs up the exterior, since interior chases can be hard to find. The fan is mounted outside the living space, and the gauge is placed where you can see it. After the install, a retest confirms how well the design is working.
Get a Design Built for an Older Home
Stone foundations need a little more thought, but they can be mitigated effectively. With the right information, the next step is usually simpler than it first seems. Clear answers up front tend to make the rest of the process calm and predictable. A careful look at the house is always the best starting point. Call us and we will connect you with a local contractor who will look at your York home, test how air moves under the floor, and write up a system designed for your basement.
Frequently Asked Questions
Can radon be mitigated in a York stone foundation home?
Yes. Stone foundation homes are common in York County and can be mitigated effectively. The contractor checks how air moves under the floor, places one or more suction points, seals floor openings and large gaps, and may add a membrane over any dirt floor sections.
How does system design change for stone versus poured foundations?
Poured foundations often need a single suction point. Stone foundations leak through many mortar joints and may sit on thin or patchy floors, so they often need more suction points and more sealing. The contractor tests the slab during the estimate to decide what the house needs.
What mess and access should we expect during install?
Expect some dust when drilling an older floor, controlled at the drill and cleaned up afterward. Clear the work areas ahead of time, since older basements can be tight. The pipe often runs up the exterior wall, with the fan mounted outside the living space.