Radon Mitigation in Andover, MA

A radon mitigation system gives the gas a way out of your house that is not through your living space. Pipe, fan, sealed entry points, and a way to confirm it is working. If you have a test result in hand and you are in Andover, we can look at it.

What radon actually is, without the scare

Radon is a gas that comes up out of the ground and gets into houses through the lowest level. You cannot smell it or see it. At high enough levels over long enough it is genuinely bad for you, which is why testing exists.

The reason we lead with testing rather than selling: your neighbour’s number is not your number. Houses fifty feet apart test differently. Get your own.

How the system works

The common approach is sub-slab depressurization. We core the slab, put a pipe into the material under it, run that pipe out and up, and put a fan on it. The fan pulls a slight vacuum under the slab so the gas goes up the pipe instead of into the basement. Then we seal the obvious entry points, the floor wall joint and any open sump, so the system is pulling from under the slab and not from your basement air.

Crawl spaces work a bit differently. The membrane becomes part of the system and we draw from underneath it.

Testing before and after

We test, we install, we test again. That second test is the whole point, and you should insist on it from anyone you hire.

603 holds a state radon measurement certification, RMS-113966.

What we will not promise you

We will not guarantee a specific radon number unless we put that number in writing for your house.

Plenty of outfits will promise you a level over the phone. We would rather test your house, install the system, test again, and show you where it actually landed. If a specific result matters to you, and for a real estate closing it usually does, get it in writing before the work starts. From us or from anybody else.

The warranty

Radon mitigation carries a 10 year warranty on system integrity and components. That covers the system. It is not a guarantee of a radon level, for the reason above.

Questions we get

My house is new. Do I still need to test?
Yes. Construction age does not tell you what is under the slab.

Is the fan loud?
You should hear a low hum at most. If a system is noisy or rattling, something is wrong with it and it is worth a call.

Does it run all the time?
Yes, continuously. Turning it off means it is not doing anything.

What about radon in water?
That is a separate test and a separate system from the air side. If you are on a private well it is worth asking about.

I am selling. How fast can this happen?
Tell us the closing date when you call. Most installs are a day.

Reading your test result

Situation	What it means	What happens next
Short-term test came back high	A snapshot, and worth acting on	Confirm, then look at the house for a system layout
Two tests disagree	Normal. Radon moves with weather and season	Longer test, or treat the higher reading as the planning number
Buyer or seller needs a number	There is a deadline attached	Tell us the closing date when you call
Finished basement, no test yet	People spend hours in that room	Test before you spend anything else on the space
Crawl space rather than a slab	Different system design	The membrane becomes part of the system
On a private well	Water is a separate pathway from air	Separate test, separate system if needed

How the job runs

It starts with a number. If you already have a test result, bring it. If you do not, that is where we begin, because there is no sense designing a system for a house nobody has measured.

Then somebody looks at the house. Where the slab is, where the pipe can run, where the fan can sit so you are not listening to it in the room above. That layout is most of the job and it is why we do not quote it over the phone.

On install day the slab gets cored, the pipe goes in and runs out and up, the fan goes on it, and the obvious entry points get sealed so the system is pulling from under the slab rather than out of your basement.

Then we test again. That second test is the point of the whole exercise, and you should insist on it from anybody you hire, us included.

What Andover’s own records say about water

Andover keeps unusually good records on this, and they are worth reading before you spend money on a basement.

The town has 29 repetitive-loss structures and 108 active flood policies, and those repetitive-loss properties have drawn $5,382,507 in building payments from FEMA across 81 separate losses (Town of Andover Hazard Mitigation Plan, public review draft, September 2024). Repetitive loss means a property flooded, was paid, and flooded again.

The same plan names the places. Residents and town staff identified Shawsheen Village, the River Street bridge, the Fish Brook area, Dascomb Road, Ballardvale and Clark Brook, North Main Street and the Skug River. Shawsheen Village came up repeatedly as the most flood-prone part of town, with the stormwater problem attributed to an undersized culvert running under the neighbourhood.

And on 8 August 2023 Andover took 8.7 inches of rain in two hours. The Shawsheen at the Balmoral Street gauge went from 24.3 feet at 6:15am to 30.6 feet by 12:45pm, past the 29-foot minor flood stage, with flash flooding near the senior center, the high school and Chestnut Street.

The layer under your basement

This is the part that explains a lot of wet Andover basements, and almost nobody tells homeowners about it.

A densic restrictive layer, which is dense basal-till hardpan, is mapped under 27.1 percent of Andover, at representative depths of 41 to 92 centimetres below the surface (USDA NRCS soil survey, Essex County Northern Part, clipped to the Andover town boundary). By series that runs Ridgebury at 46 to 49 centimetres, Paxton 53 to 71, Woodbridge 66 to 81, Montauk 74 to 92.

Hardpan does not let water through. Water moving down through the soil reaches it and turns sideways instead, and it keeps going until something interrupts it. A foundation wall is exactly that kind of interruption.

The rest of the ground splits close to evenly between thin till at 41.1 percent and coarse glacial stratified deposits at 41.0 percent (USGS Surficial Materials of Massachusetts, SIM 3402). Where NRCS rates drainage, 22.6 percent is poorly or very poorly drained.

All of that is town-scale. It is where we start, not a reading of your lot, and the inspection is free.

What our customers say

603 Basement Solutions did a great job installing a radon remediation system in my home. Communications were excellent, the installers were friendly, and the installation was tidy and professional.

David Adams, Google review, 5 stars

That is one of more than 240 Google reviews. We would rather you read them than take our word for anything on this page.

Related pages for Andover

Book a free inspection in Andover

Somebody comes out, looks at the actual space, and tells you straight what it needs and what it does not. You get a written number for a defined scope. No two hour pitch, because we would rather be at the next house.

If you are looking for a team that isn’t going to treat you like another number, we would be happy to give you an estimate free of charge. We don’t cut corners. We stand behind our work. We care.

Call 603-610-1770 or book your free inspection. We cover Andover and the surrounding towns from our shop in East Kingston, New Hampshire.

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