Wet wall behind new siding

[Chris Bernhardt]

Inspected a house recently where they had replaced the LP lap siding on the front of the house with fiber cement however at the corners of one particular window, the living room window, and below it the wall measure abnormally high with my tramex ME plus but not with the surveymaster. The pattern of the moistured anomally suggested it was moisture. I measured no detectable moisture on the interior wall and floor nor were there any moisture stains below in the crawlspace along this area.

What would your recommendation be here? I think the sheathing is either wet or mositure damaged but you can't get to it without removing some siding to confirm it.

Chris, Oregon

[kurt]

It's safe to say just that.

"The LR window corner measured high readings w/a moisture detection tool. These tools sometimes are inaccurate, but rarely; I would have to remove siding, or perform other destructive testing to know for sure.

You should obtain clearance for me to do additional testing in this area; you could have water in the wall."

That sounds clumsy, but you get the idea.

Just tell 'em what you did & what it means, and give them an avenue that can't be misunderstood.

[Jim Katen]

Originally posted by Chris Bernhardt

Inspected a house recently where they had replaced the LP lap siding on the front of the house with fiber cement however at the corners of one particular window, the living room window, and below it the wall measure abnormally high with my tramex ME plus but not with the surveymaster. The pattern of the moistured anomally suggested it was moisture. I measured no detectable moisture on the interior wall and floor nor were there any moisture stains below in the crawlspace along this area.

What would your recommendation be here? I think the sheathing is either wet or mositure damaged but you can't get to it without removing some siding to confirm it.

Chris, Oregon

I find that Hardiplank absorbs water and holds it for a while (days) as it very slowly evaporates. It's possible that you were simply detecting wet Hardiplank below the window weeps which would be harmless.

In general, using a moisture meter on Hardiplank is not a productive use of my time.

Some moisture meters ignore the wetness of the surface immediately below them and only react to wetness that's a bit further away. That could explain your anomalous readings.

I suppose if I found myself in your position, I'd gently pry up the Hardiplank and do some discrete, gentle probing or maybe do some thumping to see if I could hear a difference in the substrate.

I'd be extremely reluctant to recommend removing siding unless I had something more convincing than the word of a moisture meter.

- Jim Katen, Oregon