WOOD ROT – HOW DO I TEST FOR IT?

Q: A neighbor told me that the corner boards on my house are starting to rot. (The paint there is beginning to peel.) Can I tell if a particular spot is actually rotted? –Lane M., Roxboro, NC

A: Actually, Lane, the test for rot is very easy. Often, people suspect that they have wood rot when they only have damp wood.

HOW DO I TEST FOR WOOD ROT?

Really, the best way to test an area for rot is to simply poke it. Rotted wood is soft to the touch. Use a sharp object, like a screwdriver or an awl, to test the area. If the point of the tool sinks in less than 1/8”, the wood is probably not yet rotted.

Probing the bottom of a window casing to check for wood rot

If the area is wet but not soft, it’s not necessary to replace anything. However, do everything you can to figure out where the moisture is coming from! Prevent the area from getting any wetter.

EXCESSIVE MOISTURE ACCELERATES WOOD ROT

There are a couple typical sources for excessive moisture on exterior trim.

1. An overhead gutter is not channeling water effectively. 

Mostly, gutters overspill because they are full of leaves and need to be cleaned. Other times, the gutter pulls away from the fascia, and water falls behind it. Check the gutter above your problem area. Make sure it is removing water like it’s supposed to.

2. Water may be splashing up from ground level.

This is the typical cause of damp corner boards. Rain spills off the roof, bounces up from a hard surface, and soaks the wood.

To solve this, put down aggregate drainage material, like mulch or stone. The water won’t smash as much. Alternatively, add an aluminum diverter to the roof above this area to channel water away.

THE TAKEAWAY

First, reduce the amount of water that hits the problem spot. Second, let it dry out. Third, protect by caulking and painting it properly.

To help you out, here’s a good link for info on prepping an exterior trim spot for fresh paint.

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