4 ms·

Indeed - radon checks are a standard part of pre-purchase home inspections, because remediation can be quite expensive

Kon-Peki 3y ago
Most of the cost is the installation of equipment in the existing home. In areas of the country that have a lot of radon, it's not uncommon to install the equipment during construction of the house foundation, which then only adds a few hundred dollars to the total cost. > Radon-resistant new construction (RRNC) typically costs a builder between $250 and $750. RRNC could cost less than $250 if the builder already uses some of the same techniques for moisture control. https://www.epa.gov/radon/radon-resistant-new-construction-home-buyers https://www.epa.gov/radon/radon-resistant-new-construction-h...
- hinkley 3y ago
  Not uncommon as in it's building code in those areas. Tricky bit I think is when you live in a state with small pockets of radon instead of broad regions. Then you're back into crapshoot territory.
danbtl 3y ago
We had such a remediation done recently, in Alberta close to the rocky mountains. Costs were around $2,000 CAD to install a sub-slab depressurization system (i.e. a fan that pulls air from below the house and vents it away from the house). Radon values dropped from around 500 Bq/m3 to less than 20 Bq/m3.
- hinkley 3y ago
  Those systems must be new. The classic solution is to install drain pipes before pouring the slab, so one can imagine how difficult it would be using 1980's construction techniques to retroactively add piping below a finished house. We also had to dig trenches to lay natural gas lines, but we have a way to do those with horizontal boring techniques (of course then people who didn't know what they were doing put them straight through sewer lines, causing backups, visits from the Roto Rooter man, and subsequent explosions due to dumping natural gas straight into the sewer main). Is it safe to assume they're using something like that with perforated pipes to exhaust radon?
  - ilyt 3y ago
    >Those systems must be new. The classic solution is to install drain pipes before pouring the slab, so one can imagine how difficult it would be using 1980's construction techniques to retroactively add piping below a finished house. They didn't had diggers and drills in the 80's ?
    - iudqnolq 3y ago
      It's easy to make a hole. Making a hole underground without making a hole aboveground is harder.
      - hinkley 3y ago
        For instance, the first subway systems in London were installed via cut and cover. Dig a trench, build a roof. Usually those trenches were in the street, or a former canal, not under a building. Using modern tunnel boring equipment, Seattle's attempt to move the downtown section of 99 into a tunnel ended up stalled for a year because the ground shifted and pinched the boring machine in place. Oopsie. And of course if you're worried about gasses, puncturing a solid piece of concrete is just going to make that problem worse.
  - myself248 3y ago
    I had a side-job installing active, subslab depressurization systems in the 90s, and they were quite well established at the time. The EPA has quite clear and cogent guidance on radon, paraphrased as follows: Before going with active depressurization, start by installing a sealed sump cover, caulking the basement wall-to-floor joint, and caulking all the cracks in the basement walls, in that order. If that doesn't get the number down where you want it, drill the subslab access hole and install the ventilation piping to the outdoors, but don't install the fan in the middle. Only of those fail to get adequate results, install the fan. It's really simple and quite cheap. I don't think we ever did a job that was over $1000. Costs of running the fans were pennies a month, and Fantech still sells the classic FR-100 fan all these years later, though there are even quieter options now.

Most of the cost is the installation of equipment in the existing home. In areas of the country that have a lot of radon, it's not uncommon to install the equipment during construction of the house foundation, which then only adds a few hundred dollars to the total cost. > Radon-resistant new construction (RRNC) typically costs a builder between $250 and $750. RRNC could cost less than $250 if the builder already uses some of the same techniques for moisture control. https://www.epa.gov/radon/radon-resistant-new-construction-home-buyers https://www.epa.gov/radon/radon-resistant-new-construction-h...

hinkley 3y ago
Not uncommon as in it's building code in those areas. Tricky bit I think is when you live in a state with small pockets of radon instead of broad regions. Then you're back into crapshoot territory.

danbtl 3y ago

We had such a remediation done recently, in Alberta close to the rocky mountains. Costs were around $2,000 CAD to install a sub-slab depressurization system (i.e. a fan that pulls air from below the house and vents it away from the house). Radon values dropped from around 500 Bq/m3 to less than 20 Bq/m3.

hinkley 3y ago
Those systems must be new. The classic solution is to install drain pipes before pouring the slab, so one can imagine how difficult it would be using 1980's construction techniques to retroactively add piping below a finished house. We also had to dig trenches to lay natural gas lines, but we have a way to do those with horizontal boring techniques (of course then people who didn't know what they were doing put them straight through sewer lines, causing backups, visits from the Roto Rooter man, and subsequent explosions due to dumping natural gas straight into the sewer main). Is it safe to assume they're using something like that with perforated pipes to exhaust radon?
- ilyt 3y ago
  >Those systems must be new. The classic solution is to install drain pipes before pouring the slab, so one can imagine how difficult it would be using 1980's construction techniques to retroactively add piping below a finished house. They didn't had diggers and drills in the 80's ?
  - iudqnolq 3y ago
    It's easy to make a hole. Making a hole underground without making a hole aboveground is harder.
    - hinkley 3y ago
      For instance, the first subway systems in London were installed via cut and cover. Dig a trench, build a roof. Usually those trenches were in the street, or a former canal, not under a building. Using modern tunnel boring equipment, Seattle's attempt to move the downtown section of 99 into a tunnel ended up stalled for a year because the ground shifted and pinched the boring machine in place. Oopsie. And of course if you're worried about gasses, puncturing a solid piece of concrete is just going to make that problem worse.
- myself248 3y ago
  I had a side-job installing active, subslab depressurization systems in the 90s, and they were quite well established at the time. The EPA has quite clear and cogent guidance on radon, paraphrased as follows: Before going with active depressurization, start by installing a sealed sump cover, caulking the basement wall-to-floor joint, and caulking all the cracks in the basement walls, in that order. If that doesn't get the number down where you want it, drill the subslab access hole and install the ventilation piping to the outdoors, but don't install the fan in the middle. Only of those fail to get adequate results, install the fan. It's really simple and quite cheap. I don't think we ever did a job that was over $1000. Costs of running the fans were pennies a month, and Fantech still sells the classic FR-100 fan all these years later, though there are even quieter options now.