If your house in Creve Coeur has a radon mitigation system, there is a fair chance a pipe leaves the basement, runs up an outside wall or through the attic, and exits through the roof. That pipe is not decoration. It is the exhaust for a fan that pulls soil gas from under the slab, and it has to keep running and keep its discharge height after the new shingles go on. Before a single shingle comes off, the roof quote should say what happens to it.
Town roofing
Creve Coeur has a mix of mid-century ranches, two-story houses from the 1970s and 1980s, and newer builds in the subdivisions off the main roads. Many houses in St. Louis County were tested for radon at some point, and a high reading often led to a system installed years after the house was built. The pipe on an older house is usually a vertical stack through the roof deck, sealed with a flashing and capped at the top. A newer house may have had the system roughed in during construction, so the pipe can be routed through a sidewall or an exterior chase instead. Walk the house and find the pipe before you assume which kind you have.
The reason this matters on a roof job is simple. A roofer tearing off shingles around a stack will either cut it, pull it loose, or work around it without flashing it properly. Any of those can leave a leak at the penetration, and a leak around a radon stack is a worse problem than a leak around a plumbing vent, because the stack is also the route the system uses to move air. A loose or disconnected pipe can let the fan run without moving the gas it is supposed to move. Either way, you want to know before the tear-off, not after the first rain.
The fan itself is usually in the attic, in a crawlspace, or mounted on the pipe outside. Its power cord runs back to a switch or an outlet, and some installers route the wire through the attic. A roofer working in the attic or near the eave can disturb that wire or the fan housing. Tell the roofer where the fan sits and ask them to avoid it. If the fan has to be unplugged for the work, that step should be done by the mitigation company or with their instructions, not by guesswork.
Radon tests also change after work on the system. If the pipe is cut, rerouted, or left disconnected for a day or two, the next test may not reflect the house as it was. The usual practice is to retest after any change to the system, and that retest belongs on your list once the roof is finished. The roofer does not run that test, but the roof schedule should leave room for the mitigation company to check the fan and the pipe after the new roof is on.
What it costs
The price of a radon pipe on a roof job depends on what is being done to it. Keeping the existing stack and replacing the flashing around it is one line. Cutting the stack down to meet a new roof height, or moving it to a new location, is a different line, and it often involves the mitigation company as well as the roofer. Replacing the cap at the top with one that matches the new roof is a small item, but it should be named. Keys puts these lines into the written scope with photos and measurements, so the homeowner can see what was planned for each penetration before the work starts.
Do not let the roofer quietly absorb the pipe into a general penetration allowance without saying so. A quote that says flashings are included is not the same as a quote that says the radon stack will be flashed, sealed, and retained at its current height. The two sound alike and can cost very different amounts once the crew is on the roof. If the pipe needs to be rebuilt, the mitigation company may need to be called back for a new suction point or a fan adjustment, and that cost lands outside the roofing contract. Ask for it in writing either way.
What to ask
Before you sign, ask the roofer these questions about the radon pipe, and get the answers on paper:
- Where does the radon pipe exit the house, and will it be kept at its current height above the roof?
- Will the crew cut, move, or cap the pipe, and who decides that before the tear-off starts?
- Is the flashing around the pipe being replaced, and is that line named in the scope?
- Where is the fan located, and how will the crew avoid its wiring and housing?
- Who turns off or disconnects the fan if it has to be stopped, and who restarts it?
- Does the mitigation company need to visit before or after the roof, and who schedules that visit?
- Will a radon retest be recommended once the system is confirmed working after the new roof?
A roofer who answers these plainly is telling you the crew has thought about the pipe before the day of the work. A roofer who says the pipe will be handled as it comes up is telling you the question was not on the list. If the answers are vague, ask for a site visit before you sign, and have the roofer show you the stack and the fan in person. Keys can be reached at (314) 220-2333 to set up that visit, and the written scope will list each penetration the crew expects to find so the pipe is part of the plan from the beginning.