Radon Mitigation in Rochester, NH

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 Rochester, 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.

Rochester is not a Merrimack valley town

This matters more than it sounds, and it is the reason advice that works in Nashua sometimes does not fit a house up here.

The state’s surficial map of the Rochester and Somersworth quadrangles records sand, gravel, silt and clay deposited in or graded to the synglacial sea that occupied the estuaries in this area (New Hampshire Geological Survey). That is marine sediment. It behaves differently from the river-valley sand and gravel further south and west.

Rochester spreads across four USGS quadrangles, all in New Hampshire: Rochester, Baxter Lake, Dover West and Milton. The city sits on the Cocheco River, and its own hazard planning documents record the watersheds, the floodplain extent, and the specific places where flooding has happened before.

Soils, drainage and steep ground

The city’s plan tabulates its soils by drainage class and by soil class, along with its topography and the parts of Rochester where slopes are steep. It also documents its stratified drift aquifer, its streams and surface waters, the Heath Bog wetland complex, and a fluvial erosion assessment for the river corridors.

That last one is the sort of thing most homeowners never see, and it is genuinely useful. A river that is actively cutting at its banks is a different neighbour than one that is stable.

What we take from it

Fine marine silt and clay do not move water the way sand does. Where that material sits, water tends to sit with it rather than pass through, and that changes the right fix for a wet basement. A drainage design that suits a sandy lot in Merrimack may be the wrong answer on a Rochester lot with fine sediment under it.

It also means we do not lead with a product here. We lead with a look. If you have had a quote from somebody who works mostly down around Nashua and something about it did not sit right, this is very possibly the reason.

Everything above is city-scale and mapped at city scale. Your lot is a different question and it is answered by going and looking at it, which costs you nothing.

What the city has documented about flooding

Rochester’s plan records its NFIP status, its floodplain extent and the specific locations where localized flooding has been documented, along with its wetlands including the Heath Bog complex and the streams and surface waters across the city.

The fluvial erosion assessment covering the river corridors is the part most homeowners never hear about. A river actively cutting its banks changes the ground near it over time, which is a slower problem than a flood and a longer-lasting one.

The city also documents its steep slopes, and slope is often what decides where water arrives rather than where it falls. Water landing uphill of you is still your problem when it gets to the bottom.

What our customers say

I worked with Branden on an interior radon mitigation quote for my basement. This was a project with some complex aspects. I had a great collaboration with Branden and all my questions were answered. The installation was done with great attention to detail and exactly as I had requested, on time with no surprises. Highly recommended and very professional!

Thomas B, 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 Rochester

Book a free inspection in Rochester

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 Rochester and the surrounding towns from our shop in East Kingston, New Hampshire.

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