Question
Roots
Hi Jim,
I've read your other root answers but they didn't touch on my few points I have.
Douglas Fir, 250 years old, cut down and stump removed. The roots go under old additions to the house (living space). See attached pic. I'd like to accelerate the decay of these roots then Sept. or 2012 go in and remove the roots crawling under the house. Concerns: 1. will the decay agent produce a harmful gaseous compound that will diffuse through the subfloor and into the house living space? 2. How far does the decay agent travel down the roots? (the roots go under the house about 12 feet). I really don't want to pull up the subfloor and dig the roots out now. 3. If I leave the roots untreated, how many years will it take for them to decay (and the footings will drop?).
Thank you!
Doug
AnswerThe time it takes for roots to decay will depend on the climate where you live. Here in the Southern US roots will decay in about 2 years or less. In the Western US it maybe 5-10 years.
The organisms that rot or decay wood are called fungi. Fungi do not possess chlorophyll and consequently must derive food from other sources such as wood stumps or roots. For fungi to live and grow, they must have the proper temperature, moisture, oxygen and food conditions. Food is supplied by the stump or wood, and oxygen is supplied by contact with the atmosphere. For optimum fungal growth, the temperature should range from 50 to 90 degrees F. The wood moisture content should be approximately 20 percent to slightly higher, but not water soaked. These optimum conditions do not exist for long periods, thus stump rotting actually occurs intermittently and decay of the entire stump is a long-term process.
Fungi need moisture, warmth, air, and a food supply to grow. In the case of roots under the house the limiting factor will be the moisture. So these roots will decay very very slow and more than likely take 10-20 years or longer. Chemicals will not speed this process up much and have not had a good record on roots. Some chemical have work fairly well on stumps.
I would not worry with adding anything to try and speed the process under a house. I do not think this will help. Just let the natural decay go on as long as you realize that this may take 10-20 years for the roots to decay. I would not think you will have a problem with the foundation and IF SO it will be far down the road and slow.
To me the cost of trying to speed the rot decay is not worth it and in the long run I do not think there will be a foundation problem.
