The moisture test
One visit, one week, one report
Basements are damp more often than people think, and finishing over a wet wall is the most expensive mistake in this trade.
Denita Bankston started testing every basement before quoting after a job in her first year went over a wall that was weeping behind the paint. The test has a set fee, quoted when you book, and the fee comes off the job if you sign within 60 days. It does not include waterproofing or any repair.
What we do
A moisture meter on every wall at three heights, and in a grid across the slab
A one-foot square of plastic sheet taped to the wall and the floor, read after 24 to 72 hours
A humidity and temperature logger left in the room for seven days
A walk around the outside: grade, downspouts, window wells and cracks
The floor drain and any sump, checked and photographed
A short-term radon test kit, mailed to a lab, with the result added to the report
The result
Three answers, in plain words
You get one of these on the first page of the report.
- Quote the finish
Dry
Readings stay low and the sheet stays clear. We quote the finish as a range, then a firm number once you pick the details.
- Quote with a plan
Damp
Vapor is coming through, or a slow outside source is feeding the wall. We quote the finish with a vapor plan and tell you what to fix outside first.
- No quote yet
Wet
Water is getting in. We don't quote a finish. You get the report and a short list to hand a drainage contractor.
The report
What the report says
Here is the first page of a report for a 1,100-square-foot basement in a 1962 brick house, written the way ours are.
Readings
- North wall: 14 to 17 percent at the base, 9 percent at mid-height
- East wall: 8 to 10 percent, no change at the base
- Slab: 11 to 13 percent near the floor drain, 7 percent elsewhere
- Plastic sheet, wall: fogged after 48 hours
- Plastic sheet, slab: clear after 72 hours
Logger
Relative humidity ran 58 to 66 percent over seven days, with the highest readings after a night of rain. Temperature held between 61 and 64 degrees.
Our call
Damp. The north wall is taking water from a downspout that empties at the corner. Redirect it, wait a month and we will test the wall again. The east wall and the slab are fine to finish over, with foam against the block and a floor with an air gap.
About the test
Questions about the test
Why do you charge for it?
Because it takes a technician two hours on site, a week of logger time, a lab fee for the radon kit and a few hours to write the report. The fee comes off your job if you sign within 60 days.
Do I have to hire you after the test?
No. The report is yours, with photos, and it is written so another contractor or a waterproofer can use it.
What if it rains the week of the test?
Good. Rain is part of the test. If the week is dry, we tell you in the report and can leave the logger for a second week.
Does the test find radon?
The kit measures the radon in the room for a few days. A lab reads it and we add the number to the report. If it is high, a radon contractor installs the system. We do not.
How long before the quote?
About ten days from the visit: a week for the logger, a few days to read and write. The quote follows once you have read the report.
Book the test
Tell us the street and what the basement is like now.