Hardware Store Radon Kit or a Professional Test in Knoxville?

You picked up a radon kit, put it in the basement, mailed it off or read the result, and now you have a number. Maybe it is high and you are worried. Maybe it is low and you wonder whether to trust it. Either way you are asking the same question: is this good enough, or do I need someone to come out? Here is how we think about it.

What a kit can tell you

A kit is a fair first look. A short term kit, left in place for a few days under closed house conditions, gives you a snapshot. If it reads well above the EPA action level of 4 picocuries per liter, you have learned something real, and it is reasonable to move on to the next step. If it reads far below, the house may be fine, but a short snapshot is only a snapshot.

Why a single reading can mislead

Radon levels in a house move around. Weather, how tightly the house is closed, the furnace and the season all change how much gas gets pulled in from the soil. Where the kit sat matters too. A kit on a basement shelf and one on the second floor can give quite different results, and a kit left near a drafty window or in a bathroom can be thrown off. Knoxville homeowners also have different foundations, and a crawl space house behaves differently from a slab or a basement. Our page on radon levels in Knoxville explains how to read results.

Common situations

The kit read 4 or higher. Do not panic and do not ignore it. Do a confirming test, ideally with a continuous monitor that records hour by hour. If the second reading also lands at or above 4, a mitigation system is the usual answer.
The kit read between 2 and 4. That is a gray area, and what you do depends on your household and your plans. See radon result between 2 and 4.
The kit read low. A low reading from one kit in one spot is encouraging. If you are about to finish the basement, buy or sell the house, or use the lower level as a bedroom, get a second look with proper placement.
You are in a sale. Buyers, lenders and agents often want a documented test from a professional, with the placement and conditions recorded. A kit you bought yourself may not satisfy them. See radon testing for a home sale.

What a professional test adds

We place a calibrated continuous monitor, record the location and conditions, and keep it running for at least two days. The monitor records readings through the whole period, so you see the average and the swings, and we can tell when something was off, such as a door opened or a fan running. You get a written report you can hand to a buyer, a seller or your own files. For more on how we work, see our radon testing page.

If the second test is high

Then it is time to talk about a system. The usual approach is to draw gas from under the slab or from beneath a sealed crawl space liner and vent it outside through a fan and pipe. We explain the options on the radon mitigation page, and the cost guide covers what shapes the price. After installation we test again so you see the number come down.

What not to do

Do not move the kit around to see if it changes, and do not open windows right before a test to get a lower number. If you are testing for a sale, tampering with the conditions can be spotted and can make people trust the result less. If you want a clean result, test under the proper conditions and fix the house if it needs fixing.

Call and tell us what the kit said

Call (865) 563-8112 with the number, where the kit sat, the type of foundation and why you are testing. We will tell you whether a kit result is enough for your purpose or whether to retest with a professional monitor.