Your building

Your home is slab on grade

“The house sits directly on a concrete slab — there is no basement or crawl space.”

A slab-on-grade house has no below-grade level, but the slab itself is in contact with the soil across the whole footprint, so soil gas entry is possible in the same way.

The occupied floor is the lowest level, which means the measurement and the living space are the same place — unlike a basement house, where they are usually not.

Why this matters

What it changes about the decision in front of you.

The slab, its perimeter joint, and any penetrations are the entry paths, and they sit directly under occupied space.
Because there is no buffer level, a given entry rate produces a reading in the space people actually use.

What it could influence

Where the effect is likely to show, and in which direction where that is knowable.

Interior routing options may be more limited than in a basement house, which affects how a system would be arranged.
Post-tension slabs and slabs with in-floor heating constrain where anything can be cut, which is a design question rather than a measurement one.

What this does not settle

What still stands. Noticing a problem is not the same as losing the evidence.

A slab house is not inherently lower or higher risk than a basement house — it is a different geometry, not a safer one.
The absence of a basement does not mean the absence of an entry path.
It does not determine whether sub-slab depressurization is feasible here, which depends on what is beneath.

What a professional is likely to ask

Worth having answers ready. None of these is a test you can fail.

Whether the slab is post-tensioned, and whether there is in-floor heating.
Where the perimeter joint is accessible and where penetrations are.
What the exterior offers for routing, since interior options may be constrained.

What you can check yourself

Things you can establish today, without anyone visiting.

Visible cracks and the perimeter where the slab meets the wall.
Whether there is in-floor heating, which the household usually knows.
Where utilities enter through the floor.

What genuinely needs somebody on site

Where this platform stops. These are not questions a website can answer about your house.

Whether the material under the slab will allow pressure to extend from a suction point, which requires a diagnostic.
Whether the slab is post-tensioned, if nobody has the drawings.

Categories a next step could fall into

Unordered, and none of them is a recommendation. Which applies depends on things this page does not know about your situation.

Request a professional assessment

When it is considered. When the building itself is part of the question — foundation type, an existing system, access, or an unusual layout.

What it would establish. What the building is doing, which no amount of information typed into a website can establish.

Review the testing context

When it is considered. When the conditions, placement, or duration of the test are unclear, which is the most common situation and the cheapest to resolve.

What it would establish. Whether the existing result is something to reason from, or something to repeat under conditions that can be described.

Sources

U.S. EPA — Consumer’s Guide to Radon Reduction

When you are ready to talk to somebody

Tell us about your home and what you are trying to work out. We will tell you honestly whether we can route it to a provider in your area today.

Start a request