Don't Panic
What happens if the radon test comes back high before closing?
The short version: A high radon test before closing almost never kills a deal — it's one of the most fixable things an inspection turns up. Mitigation runs $1,500 to $2,500, the install is usually a one-day job, and the whole thing typically resolves as a simple negotiation between "the number came back at 5.8" and "we closed on Friday." This page is the calm walk-through of exactly how that happens.
4.0pCi/L
EPA action level
$1,500–$2,500
typical Birmingham metro install cost
1day
typical mitigation install time
Put It In Perspective
An elevated result is a fixable defect, not a broken deal.
A high radon number can feel scarier than a bad HVAC report or a failed sewer scope, mostly because radon is invisible and unfamiliar — the number feels bigger than it is. Put it next to the other line items on a typical Birmingham metro inspection and the shape gets clearer: an elevated radon result is one of the smaller, more predictable, more solvable items on the page.
A sub-slab depressurization system — that's the fan-and-vent setup that pulls the radon gas out from under the slab before it can enter the house — is the standard fix on Birmingham metro slabs and basements. Most systems bring the number well below 2.0 pCi/L, some to almost undetectable. That's the honest track record. The negotiation that follows a high result isn't a rescue mission — it's just a decision about who pays and when, and it usually finishes inside your inspection window.
Three Paths
The three negotiation paths, and when each is right.
Nearly every Birmingham metro deal with a high radon result lands one of three ways:
Path A — Seller installs the system and shows you a post-fix test
The seller hires a certified mitigator, the system goes in, and a fresh post-mitigation test — run by an independent tester, not the mitigator — comes back before closing. This is the cleanest outcome for a buyer: known number, verified fix, no money to shuffle at the closing table.
When it fits: When there's time left on the contingency clock and the seller wants the sale to go smoothly.
Path B — Credit at closing to cover the fix
The seller credits or splits the cost of the mitigation system at closing — usually $1,500 to $2,500 for a Birmingham metro sub-slab fan-and-vent system — and you install it after you move in. Testing to verify the fix runs on your schedule, not on the contingency clock.
When it fits: When the days left are tight or you'd rather pick your own mitigator.
Path C — Price reduction
The purchase price drops by the estimated cost of mitigation and you handle the install after closing. This is often cleaner on paper for lenders that limit how much a seller can credit at closing — but the timing of the fix is entirely on you.
When it fits: When lender rules cap seller credits, or you want full control over the timeline.
All three are reasonable. Which one lands depends on how many days you have left on the inspection clock, whether you already have a mitigator you like, and what the lender lets the seller credit at closing. None of them requires the deal to fall apart.
Rules For A Retest
The retest rules that matter (and the one nobody should break).
A single 48-hour reading has natural swing — the number can come in 20 to 30 percent above or below the home's true long-term average, depending on weather, how the HVAC cycled, and what happened in the house during the test. So a confirming retest is often the right move when the first number lands close to the action level (say 3.5 to 4.5 pCi/L). Two rules keep it honest:
- Same setup both times. House closed up before and during the test, continuous monitor, same footprint of the home. The standard is what makes two numbers comparable.
- No cherry-picking. A retest is not a second-chance draw. Report both numbers. For a real-estate decision, either take the higher of the two or average them — either is defensible. Running tests until a friendly number lands is not.
The one nobody should break: the mitigator does not grade their own fix. The post-install verification test — the one that proves the system brought the number down — should always be run by someone independent, not the crew that put the system in. That separation is the whole point of the ANSI/AARST rules. It's also why we test and don't install, and why reputable mitigators never test their own work. If a seller's mitigator is offering to test the system they just installed, push for an independent tester instead. More on this on ourfixing radon page.
How It Plays Out
What it looks like inside a 10-day inspection window.
Start the radon test on day one or two, get the result back by day five, and there's still real time on the clock for a mitigation conversation. That's the whole reason timing matters here. What a realistic sequence looks like when the number lands at or above 4.0 pCi/L on day five:
- Day 5–6 — your agent sends the report to the listing side with an ask for mitigation.
- Day 6–7 — seller gets a mitigation quote (or two). You negotiate Path A, B, or C.
- Day 7–8 — if Path A, the mitigator schedules the install; if Path B or C, the inspection contingency gets signed off with credit or price-reduction language.
- Day 8–10 — system goes in (Path A); the post-install verification test gets booked with an independent tester.
On a deal where nobody ordered the radon test until day six of the window, none of that room exists — and the conversation gets much harder. That's the whole reason the buyer-side discipline is to order the test on day one or two, before the general home inspection has even happened. The full walkthrough is on ourbuying a house in Alabama page.
Why Deals Don't Die On This
Why deals rarely die on an elevated radon result.
Three reasons a high radon test before closing almost never kills a Birmingham metro deal:
- The fix is standardized. Sub-slab depressurization is the same solution on almost every Birmingham metro foundation. Quotes come back fast, systems go in fast, and the post-install number is predictable.
- The cost is modest. $1,500–$2,500 installed. That's a smaller number than most inspection negotiations end up centered on.
- The seller has a reason to fix it. Once a bad test result exists in the seller's file, Alabama'shealth-and-safety exception to caveat emptormeans the number is very likely going to follow the house to the next buyer anyway. Fixing it and documenting the fix is often the cleaner outcome for the seller too.
If the house already has a system on it, seebuying a house with a radon mitigation system. For the full 10-day walkthrough, seeradon testing when buying a house in Alabama.
Independent verification test after mitigation — $295 flat.
FAQ
Frequently Asked Questions
Is a high radon test really a deal-killer?
Almost never. A radon mitigation system in the Birmingham metro typically runs $1,500 to $2,500 installed, and most jobs finish in a day. Compared to the usual things that get negotiated on a home inspection here — roof, HVAC, foundation, sewer scope — an elevated radon result is one of the more predictable, more affordable, more standardized fixes on the list. Deals die because problems come back late, not because they come back.
Can we just retest and go with the lower number?
A retest is a fair move — any single 48-hour result carries about 20–30% swing room, so a second reading often closes the question. What isn't fair is retesting until a friendly number shows up and using that one. The real-estate standard requires retests to be run under the same closed-house conditions as the first, and best practice for a real-estate decision is to average the two or take the higher one. Cherry-picking isn't the tool for the job.
Should the mitigator run the post-install test?
No. The person grading the fix shouldn't be the person who did the work. That's the whole point of the ANSI/AARST rules keeping testers and mitigators separate — and it's why we only test (we never install), and why reputable mitigators never test their own work. Ask for the post-install test to be run by an independent tester — our flat rate is $295.
How long does mitigation take once the system is ordered?
The install itself is typically a one-day job on a Birmingham metro home once the crew is on site. Scheduling is usually the bottleneck — most reputable mitigators are booked one to two weeks out. On a tight inspection window, Path B (credit at closing) is often calmer because it moves the install off the contingency clock.
Does a high radon test have to be disclosed to future buyers?
If the current seller is holding a result above the EPA action level, Alabama's health-and-safety exception to caveat emptor ("buyer beware — in Alabama, sellers generally don't have to volunteer problems") almost certainly kicks in — see our page on Alabama radon disclosure. Practically: once a bad test exists, the responsible move is to keep the paperwork with the house and to have a post-mitigation test showing the number came back down. That documentation protects the seller as much as it protects the next buyer.