Radon mitigation cost dataset

What the foundation changes

National figures for the default house: 1,200 sq ft of slab, two storeys, exterior pipe route, slab sealed, post-mitigation test included.

A crawlspace roughly doubles the job, and the reason is a sheet of plastic. Under a slab the gravel is already the suction layer; under a crawlspace there is nothing to draw from until a sealed membrane is laid over the soil, and that membrane is most of the difference between $2,618 and $5,340.

The number that decides the price

One fan can only depressurise as much slab as the material underneath will let it reach. Clean gravel carries suction a long way; fine soil or sand barely carries it at all, and then the slab needs a second point and sometimes a second fan.

These three coverage figures are our estimate and nothing else. There is no published federal table of square feet per suction point, and we will not pretend otherwise on the single number that carries the most weight on this page. A contractor settles it with a communication test: drill a hole, pull a vacuum, and measure how far the pressure field actually reaches under your slab. That test is a line item here, and it is the only thing that turns this estimate into a quote.

What the pipe route adds

The interior route costs about $1,474 more, and almost none of that is pipe. It is the framing, boxing, drywall and paint that hide it, plus a roof penetration that has to be flashed and not just sealed. It is bought for appearance, which is a legitimate reason, but it should be quoted as appearance rather than as engineering.

Two cases where the number falls a long way

The fan has failed on a system that already exists — $724

Fans run continuously and last somewhere around five to ten years. Replacing one is an hour of work and a part; it is not a new system, and it should never be quoted as one. Range $431–$1,017.

The crawlspace is already encapsulated — $1,841 instead of $5,340

The soil-gas membrane and the encapsulation liner are the same sheet of plastic, bought once and laid once. If it is already down, this job is a fan, a riser and a monitor, and that is $3,499 off the price. Our crawl space encapsulation calculator prices the liner, so nothing on this site charges you for it twice.

Line items

The slab lines and the crawlspace lines are alternatives on most houses and appear together only where a home has both. Optional lines appear at quantity zero when the corresponding answer is no.

The reasoning behind each figure

Written out so a certified mitigator can point at the exact assumption that is wrong. A number with no reasoning behind it cannot be corrected.

Sub-slab communication test and system design

• Drill a small test hole, put a vacuum on it and measure whether the suction actually reaches the far corners. It takes about two hours and it decides every other number on this page: how many suction points, how much pipe, which fan.
• This is the first line to disappear from a cheap quote, and it is the one that separates a designed system from a guessed one. A price quoted before anyone has tested the slab is a price for a hope.
• A house with two different foundation types needs the test run twice, so we model three hours instead of two.
• BLS publishes no occupation called radon mitigator. We use 47-4041, Hazardous Materials Removal Workers, as the closest published trade, falling back to the 47-0000 major group where BLS does not publish 47-4041 in your area. The wage is official; the hours are our estimate.

Core bit wear, pipe boot and polyurethane seal at each suction pointestimated, ±49%

• Materials and consumables only: the share of a diamond core bit that this hole wears out, the boot that carries the pipe through the slab or the liner, and the polyurethane that seals the penetration back up around it.
• Digging out the pit under the hole is NOT in here. That is labour and it is charged once, in the mitigation hours below, at three hours per cored point. Pricing the same pit in both places is how a breakdown quietly counts a job twice.
• The bottom of the band is a suction point under a crawlspace liner, where there is no concrete to cut at all. The top is a thick reinforced slab that eats bit and takes two passes.
• How many of these a house needs is the single biggest cost driver on this page, and it comes from the diagnostic test above, not from the square footage of the house.

Dust containment sheeting, HEPA vacuum filters and wet-cutting water managementestimated, ±55%

• Coring a four- to five-inch hole through a concrete slab inside a finished basement produces slurry and respirable crystalline silica dust. Either the cut is wet or the dust is captured at the bit; there is no third option that leaves the room clean.
• Materials only: sheeting, tape, a HEPA filter and the bags the debris leaves in. The hours to build the containment and strike it again are the line below.
• The bottom of the band is one hole in an unfinished basement with a shop vacuum and a drop cloth. The top is a finished, furnished room where the containment has to be built and the floor protected.
• Filters and sheeting are ordered nationally and carry no regional adjustment, which is why they sit on their own line and the declared percentage describes this band alone.
• This line is zero where nothing is cored: a crawlspace system and a pure fan swap never touch concrete.

Radon technician: build the dust containment and strike it afterwards

• Between half an hour and an hour: hang the sheeting, mask the floor, set the vacuum on the bit, and then take the whole containment down and bag it once the coring is finished.
• The wage is official BLS data adjusted to your metropolitan area; the hours are our estimate. This is the half of dust control that moves with where you live, and the materials above are the half that does not.
• Zero where nothing is cored, exactly like the materials: a crawlspace system and a fan swap never cut concrete.

Schedule 40 PVC riser and manifold, fittings, hangers and rain capestimated, ±36%

• Averaged across the whole run rather than itemised fitting by fitting: pipe, couplings, elbows, straps and the rain cap. A short exterior riser needs four elbows and six straps, and those cost more per foot than the pipe does.
• EPA specifies solid Schedule 40 PVC of three or four inches, run to above the roof, for radon-resistant construction. A retrofit copies that specification, which is why the pipe ends above the eave or the ridge and never at ground level.
• Three-inch pipe sits at the bottom of the band and is fine on a short exterior run. Four-inch is what a long run or a cold climate needs: a narrow pipe throttles the fan and ices shut sooner where the discharge sits above a cold roof.
• Commodity plastic made and shipped nationally, so the band is narrower than most lines here. Geography barely touches this material; it is the hours above and below it that move with your metro area.

Radon fan, low-suction high-flow, for clean gravel under the slabestimated, ±27%

• A sealed, continuous-duty unit built to be mounted outside the living space, so that anything it leaks goes outdoors. It is not a bathroom fan and the two are not interchangeable.
• Clean coarse gravel under a slab moves air easily, so the fan that suits it moves a lot of air at low suction. It is the cheapest fan on this page and the cheapest to run: this class typically draws 20 to 50 watts, and it runs every hour of the year.
• The band is narrow because this is a mature commodity with three or four dominant models and a well-known street price. A band that stayed wide here would be padding, not uncertainty.

Radon fan, mid-range, where the sub-slab material is unknownestimated, ±53%

• When nobody knows what is under the slab, nobody knows which fan the house needs until the communication test says so. That is not a hedge: it is the honest shape of the number before the test, and it is why this band is the widest of the three.
• The bottom is the low-flow fan that a lucky slab turns out to need. The top is the high-static unit that a tight one demands. The test is what collapses this band to a single price, and it costs about two hours.
• The same uncertainty runs through the electricity: between about 20 and 150 watts continuous, depending which end of this band the house lands on.

Radon fan, high-static, for fine soil with little aggregateestimated, ±24%

• Tight sub-slab material will not let air travel sideways, so the fan has to pull hard rather than move volume. This is the expensive class of fan, and the condition that demands it is the same condition that adds suction points, so the two increases genuinely do arrive together here.
• It is also the class that costs most to run: a high-static unit draws roughly 100 to 150 watts continuously, several times the low-flow fan above.
• Narrow band, for the same reason as the low-static line: a handful of models, a known street price. The uncertainty in this scenario lives in the number of suction points, not in the fan.

U-tube manometer and system labelestimated, ±37%

• The cheapest line on this page and the only part of the system a homeowner can read without tools: two columns of liquid at different heights mean the fan is pulling. Level columns mean it stopped, possibly months ago.
• The band is narrow because it is two commodity items — a plastic U-tube and a printed placard. The top of it is an engraved permanent label rather than a sticker.
• One per fan, so a house with a basement and a crawlspace gets two, one on each riser.

Audible or connected fan-failure alarmestimated, ±54%

• A manometer only works if somebody looks at it. An alarm is what tells you the fan died while you were away, which is the failure mode that matters: a stopped radon fan makes no noise, no smell and no mess.
• The bottom of the band is a pressure switch with a buzzer. The top is a connected unit that messages a phone, which is what makes it useful in a house that is empty half the year or in a rental.

Backer rod and polyurethane sealant for the perimeter joint, cracks and penetrationsestimated, ±62%

• Backer rod and polyurethane along the joint where the slab meets the wall, plus visible cracks and the gaps around pipe penetrations. Materials only, priced per foot of joint.
• Sealing is not cosmetic. Every unsealed opening is a path for the fan to pull heated indoor air down and out of the house instead of soil gas: it costs you on the energy bill and it steals suction from the far corners of the slab, which is exactly where the suction is needed.
• The band is wide — over four to one — because it is driven by joint width, and sealant volume goes up with the square of it. A clean quarter-inch joint takes one bead; a three-quarter-inch gap that has to be chased out, vacuumed and primed takes several times the material.
• Sealant and rod are nationally shipped commodities and carry no regional adjustment. The time it takes to apply them does, and it is on the line below.

Radon technician: seal the perimeter joint and the slab penetrations

• Roughly two to three and a half minutes for every foot of joint: chase out whatever is loose, vacuum the channel, push the backer rod down to depth and run the bead over it.
• The slow end of that is a wide or dirty joint that has to be cleaned and primed before anything will stick to it, which is the same condition that puts the material at the top of its band.
• The wage is official BLS data adjusted to your metropolitan area; the hours are our estimate. BLS publishes no occupation called radon mitigator, so the hour is priced at 47-4041, Hazardous Materials Removal Workers, the closest published trade.

Stock gasketed sump cover with grommets, fitted and sealedestimated, ±56%

• A sump pit is an open shaft straight into the same gravel layer the fan is trying to depressurise. Left with a loose lid it short-circuits the whole system: the fan pulls basement air up the pipe and the slab stays exactly where it was.
• This is a retrofit cover for an existing standard round pit — a gasketed lid with grommets for the discharge pipe, the float cable and the power cord, clamped down rather than laid on. It is not the same object as the basin-and-lid line on our sump pump page, which prices a complete new pit.
• Because the sealed pit becomes a suction point, this line removes one cored penetration from the count above rather than adding to it, which is one of the few ways this job gets cheaper instead of dearer.

Sump cover fabricated to fit, with gasket and pipe grommetsestimated, ±38%

• An odd-shaped pit, an oversized one, or one with several pipes and a discharge line through it. The lid is cut, drilled and gasketed to that pit, and none of that is a shelf product.
• The band separates a sheet of polycarbonate cut and sealed on site from a moulded cover made to a measured template with cast-in fittings. Same job, two very different afternoons.
• As with the stock lid, sealing the pit turns it into the suction point and removes one cored hole from the slab.

6-mil polyethylene soil-gas sheeting, seam tape and pier sealantestimated, ±32%

• The cheap end of a crawlspace system: plain 6-mil polyethylene sheeting, plus the tape for the laps and the sealant for the piers. EPA specifies 6-mil poly as the soil-gas retarder for radon-resistant construction, so this is the specified minimum rather than a corner cut.
• It is a minimum, though, and it behaves like one. It tears where anyone crawls on it to service a duct, and a torn liner is a liner with a hole in the suction surface.
• Sheeting is a commodity made and shipped nationally, which is why this band is one of the narrowest on the page and why nothing here is adjusted for your metro area. The hours on the line below are.
• The 15% added to the crawlspace footprint is turn-up at the walls and around the piers, not a waste allowance.

Radon technician: lay, lap, tape and seal the 6-mil membrane

• About one minute per square foot — roughly 21 hours on a 1,200 sq ft crawl. Dragging and sealing sheeting on your elbows in three feet of headroom is slow, and that figure is not padding.
• Most of that time is the edges rather than the open floor: turning the sheet up the walls and sealing it around every pier is what makes the liner a suction surface instead of a dust cover.
• The wage is official BLS data adjusted to your metropolitan area; the hours are our estimate. This is the half of a membrane job that moves with where you live.

Reinforced 12–20 mil liner, seam tape, termination bar and sealantestimated, ±29%

• This is what makes a crawlspace system a different job rather than a variant. The liner IS the suction surface: without it there is nothing to depressurise, so the membrane is structural to the design even though it looks like housekeeping.
• String-reinforced liner, plus the seam tape, the termination bar that holds it to the walls and the sealant at the piers. What you buy over the 6-mil option is that it survives somebody crawling over it three years later.
• The 15% added to the footprint is turn-up at the perimeter and around piers, not waste. Waste on a cut-up crawl is higher than that and sits inside the band.
• Liner, bar and tape are manufactured goods bought nationally, so this material carries no regional adjustment; the hours on the line below do.

Radon technician: fasten, seal and terminate the reinforced liner

• About a minute and a half per square foot — around 35 hours on a 1,200 sq ft crawl, which is the single largest labour item on this page and the reason a crawlspace system costs what it costs.
• Mechanically fastening a termination bar to the walls and sealing the liner around every pier is what separates these hours from rolling sheeting out over the ground and calling it done.
• The wage is official BLS data adjusted to your metropolitan area; the hours are our estimate.

Foundation vent inserts: rigid foam or cut block, foam and sealantestimated, ±51%

• A sub-membrane system in a vented crawlspace either seals the vents or needs a much bigger fan, because those are the only two physical outcomes. An open vent is the same short circuit as an open sump pit, and it is the one that gets forgotten.
• Rigid foam or a cut block insert with the canned foam and sealant that close its edges, one per vent. The bottom of the band is a foam plug in a standard block opening; the top is a masonry infill in an oversized or damaged one.
• Vent count is modelled at one per 150 sq ft of crawlspace, floored at four and capped at ten. That is our estimate, not a code figure, and it exists because nobody counts their crawlspace vents before asking what a system costs.
• Board, foam and sealant are commodity goods bought nationally, so this material carries no regional adjustment.

Radon technician: cut, fit and seal each foundation vent

• Twelve to twenty minutes a vent: measure the opening, cut the insert to it, push it home, foam the perimeter and trim the foam back once it has gone off.
• The slow end is a damaged or oversized opening that has to be made good before anything will seal against it, which is the same vent that sits at the top of the material band.
• The wage is official BLS data adjusted to your metropolitan area; the hours are our estimate.

Roof penetration materials: flashing, boot and above-roof terminationestimated, ±56%

• Flashing, boot and the section of pipe standing above the roof line. Materials only: the hours to cut, flash and weather the hole are the roofer line below, because that is local trade time and it has to be adjusted to your metro area like any other hour.
• EPA specifies discharge above the roof for radon-resistant construction, which is why an interior route always ends up going through the roof rather than out of a gable wall at a convenient height.
• The bottom of the band is a stock rubber boot on an asphalt shingle roof. The top is tile, slate or standing-seam metal, where the flashing is a fabrication and the boot is the least of it. That is the four-to-one spread in this line.
• On an exterior route this line is zero: the pipe simply terminates above the eave on the outside of the wall.

Roofer: cut, flash and weather the roof penetration

• Only on interior routes, where the pipe leaves through the roof rather than past the eave. Two hours per riser, and three on the second one is not unusual if the roof is steep.
• Many mitigation companies flash their own penetrations rather than subcontracting. We price the hour at the roofing wage anyway, because roofing is the skill being sold in that hour, and a flashing done badly shows up as a ceiling stain two winters later, long after anyone connects it to the radon system.
• Metro-adjusted wage from official BLS data; the hours are our estimate.

Chase materials: framing, board, tape, compound and paintestimated, ±51%

• Studs, a sheet and a half of board, tape, compound, primer and paint for the box that hides the riser where it passes through a closet, a garage corner or a finished room, plus the ceiling and attic-floor penetrations on the way up.
• Materials only. The hours to build it, tape it and paint it are three separate trade lines below, and they are worth more than these materials by a factor of three.
• Technically this line buys nothing at all. It exists because the alternative is a white four-inch pipe running up the outside of the house, and that pipe is the one thing sellers consistently dislike about these systems.
• The band separates a run boxed into an existing closet from one crossing finished ceiling space, where the patching is the bigger half of the work.

Carpenter: frame the chase and cut the floor and ceiling penetrations

• Five hours to open the route, cut through the ceiling and the attic floor, frame a box around the riser and put back any trim that came off. This is the line that most quotes fold silently into a lump sum.
• It is also the reason the honest gap between an outside pipe and a hidden one is far larger than the pipe itself suggests: the pipe is the same pipe, and everything around it is different work.
• Metro-adjusted wage from official BLS data; the hours are our estimate.

Drywall installer: board, tape and finish the chase

• Five hours across more than one visit, because compound has to dry between coats. Boarding a chase is quick; making the corners disappear is not, and a chase with visible joints is a chase everybody looks at.
• These are the hours the material line above has no way of containing, and leaving them out is what makes a published interior-route figure look plausible and read as low to anyone who has done the work.
• Metro-adjusted wage from official BLS data; the hours are our estimate.

Painter: prime and paint the chase and the patched finishes

• Three and a half hours to prime the new work and paint it out to a corner, because a patch painted only where the patch is stays visible in raking light for the life of the wall.
• This is the last of the three trades that an interior route needs and the first one a cheap quote leaves for the homeowner. Whether that counts as a saving depends on whether you own a roller.
• Metro-adjusted wage from official BLS data; the hours are our estimate.

Fan circuit materials: cable, weatherproof box and labelled service switchestimated, ±63%

• Cable, a weatherproof enclosure at the fan and a labelled switch so the fan can be isolated for service without hunting for a breaker in a dark basement.
• The band is over four to one and it is honest: the bottom is a fifteen-foot tap off an existing attic or garage circuit, the top is a sixty-foot home run back to the panel with its own breaker. Those are genuinely different jobs and the materials say so.
• One per fan. A house with a basement and a crawlspace gets two fans in two places, so it gets two enclosures and two switches, not one of each.
• The fan runs continuously and should not share a circuit with anything that can trip it, for the same reason a sump pump should not: nobody notices a breaker that went days ago.

Electrician: power the fan and fit the service switch

• Two hours per fan where it hangs on an outside wall within reach of existing power. Three where an interior route puts it in the attic and cable has to be run up to it through insulation.
• Two fans in two locations are two lots of this work, not one, which is a detail that quietly doubles a line most breakdowns treat as fixed.
• Metro-adjusted wage from official BLS data; the hours are our estimate.

Radon technician: core, pipe, seal, commission and check the appliances

• Seven hours of fixed work whatever the house: setting up, protecting the route, cutting in, starting the fan, measuring the suction it achieves and writing it down. Three quarters of an hour of that fixed block is a combustion-appliance backdraft check, which belongs to commissioning and not to a later visit — depressurising the ground under a house changes the pressure balance inside it on the day the fan is switched on, not eventually.
• Three hours for each cored suction point: a hole through concrete, a pit excavated underneath it by hand, a sealed connection and a length of manifold. A point under a crawlspace liner is lighter work at an hour and a half, because there is no concrete.
• Routing the pipe inside the house adds five hours per riser instead of two, since it has to be threaded through finished space and out through the roof. The trades that then make the house look untouched are separate lines.
• Sealing an existing sump pit adds an hour: the lid has to be fitted, the pipes and cables grommeted, and the seal checked with the fan running. Neither the perimeter sealing nor the crawlspace membrane is in here — both carry their own hours in their own lines, so nothing is charged twice.

Performance allowance: priced-in cost of adding a suction point if the first attempt falls shortestimated, ±47%

• Most US mitigators guarantee the result rather than the parts: if the finished system does not bring the house below the action level, they come back and add a point at their own cost. That risk is priced into every real quote, typically at five to ten per cent of the parts of the job it could affect, and it is money you pay whether or not it is ever spent.
• Expressed here per suction point, so a three-point system carries three times the allowance a one-point system does. That is the right shape: the more points a slab already needs, the tighter the material and the likelier a fourth becomes.
• A quote without this allowance and a quote with it are not the same product, even at the same price. Which one you have is worth asking, because the answer is written in the warranty, not in the total.

Radon technician: swap the fan and re-commission the system

• Two hours: isolate the circuit, cut the couplings, fit the new fan, re-seal both joints, restart and read the manometer to confirm the system is pulling what it pulled when it was new.
• A fan is a consumable on a machine that runs every hour of every year, so this is the most common radon job in the country and the one no cost guide bothers to price. It is also the one where the pipe, the wiring and the sealing are already paid for.
• Metro-adjusted wage from official BLS data; the hours are our estimate.

Remove and dispose of the failed fanestimated, ±64%

• A small line, listed because it appears on real invoices: couplings, fresh sealant and getting rid of a unit that has been sitting outdoors pulling soil gas for a decade.
• The top of the band is where the old fan is seized into its couplings and the pipe has to be cut and re-joined rather than unclamped.

Post-mitigation test: kit or monitor use and laboratory analysisestimated, ±58%

• The consumable half of the test: a lab-analysed charcoal or alpha-track kit at the bottom of the band, or the use of a continuous monitor and its report at the top.
• A continuous monitor returns an hourly curve rather than one averaged number, which shows whether the house was actually closed during the test. That is why the two ends of this band are not the same product at two prices.
• Without this, nobody — not you, not the contractor, not a future buyer — knows whether the system worked. It is the only line here that produces evidence rather than hardware.

Return visit to place and collect the test, and issue the report

• Two hours across two trips: place the device once the fan has been running at least twenty-four hours, come back for it, read it and write the result up.
• This is local trade time, so it belongs in hours and not inside a materials price. A return visit costs what an hour costs where you live, and hiding it in a flat fee would quietly exempt it from the regional adjustment that the rest of this page runs on.
• Metro-adjusted wage from official BLS data; the hours are our estimate.

Not included in this dataset

Encapsulating the crawlspace

This page prices depressurisation: the communication test, the suction points, the pipe, the fan, the manometer and the electrics. Where a crawlspace has to be lined for the system to have a suction surface, that liner is priced here — but only once. If the crawlspace is already encapsulated, or is about to be, the liner, the vents, the rim joist and the dehumidifier belong to /crawl-space-encapsulation-cost and this calculator drops the membrane to zero. It is the same plastic over the same ground, bought once.

Vermiculite insulation and any asbestos-containing material

Coring a slab in a house built before 1980 can mean cutting through nine-inch vinyl tile or its black adhesive, and some crawlspaces and attics hold vermiculite. Neither is budgeted here, at any figure. Both require testing first and licensed specialist work that this estimate does not cover, and putting a low number against that work would be worse than putting none.

Permit fees and state certification

A growing number of states license or certify radon mitigators, and some jurisdictions require a permit for the electrical work. Fees vary by jurisdiction with no national source, so they are excluded and declared rather than averaged into a number that would be wrong everywhere.

The radon test that sent you here

These figures assume you already have a result. The measurement itself — a kit, or a professional test inside a real estate inspection period — is separate work, and it is the cheapest step in the whole sequence.

Clearing out the crawlspace before a liner goes down

A membrane goes over whatever is already on the crawlspace floor. Removing debris, old torn sheeting, rubble or standing water, and fixing the drainage that put the water there, is separate work and can cost more than the mitigation system itself.

Running the system: electricity and fan replacement

These are installation figures. The fan runs continuously, so it draws power every hour of the year and it wears out. This calculator can price the replacement itself — switch the scope to a fan replacement — but the electricity is not in any total here.

Correcting a venting problem the commissioning check finds

The backdraft check on an atmospherically vented furnace or water heater is part of commissioning and it is in the technician hours. Fixing a venting fault that the check reveals is not: that is separate work on a different appliance, and it is also why the answer to a stubborn reading is never simply a bigger fan.

Radon in well water

Waterborne radon is a different problem with a different fix — aeration or granular activated carbon at the point of entry — and none of it is priced here. It matters mainly on private wells, and an air system will not touch it.

Structural repair of the slab

Sealing a crack against soil gas is not repairing it. A crack that is still moving, or a slab that has settled, needs fixing on its own terms first, and sealant applied over live movement will simply tear again.

What your insurance policy covers

We do not model it and we will not guess at it. What a homeowners policy covers is set by that policy: your own documents and your insurer are the only sources that can answer it for your house.

Where the non-price facts come from

The action level is published by the EPA, which EPA, What is EPA’s Action Level for Radon and What Does it Mean? states as 4 pCi/L, and which also recommends considering a fix between 2 and 4 pCi/L. Whether your county is one where high readings are common is in the EPA, Map of Radon Zones, which is a planning map and never a substitute for testing your own house. Both retrieved 2026-08-22.