Rotten woo or wood with insects

Asked October 6, 2019, 3:25 PM EDT

I have seen other similar responses but still unsure. Neighbors and others have said rotten wood from a low spot possibly with rain and snow and heat and cold. I had terminex out and of course they said termites and wanted to do the soil treatment. The jury is out and still unsure which it is. I have a walkout basement and the deck is far above the ground/dirt. Poles or posts are certainly holding everything g up and they rest on concrete. The damage is in the joists coming out from the house and farthest away from the house. I am either going to replace the joists or sister them but I sure would like an unbias opinion of what is causing or caused this damage. Any suggestions or advice? By the way, the deck was built in 1994, 25 years. Thanks.

Arapahoe County Colorado

2 Responses

I don't see any insects or evidence of insects in these pictures, especially #2. My best guess is long term decay due to exposure to moisture and other environmental factors. 25 years is pretty good longevity for well-maintained pressure treated wood.

Thank you for the response. As I said the only person I asked about this said rotten woo except of course the terminex guy. Not that it matters to you but it took him maybe 2 secs to say termites. To add/alter your response there is no pressure treated wood in my deck. ALL of it is original redwood. Thanks again!