garage floor is 15 yrs old. While power washing to apply epoxy this wood in the floor shows up. I must have stripped the thin layer of concrete off. Can I just patch over it? Any suggestions appreciated.
I agree. Leaving it there allows for moisture to wick up. If possible take it out down below grade. If you use a big drill bit, the sides should come out real easy.
Or, you might be able to just pound it down.
Make sure you clean up that hole real good and roughen the sides. If it was me, I'd slope the sides a little to the patch can't push into the hole.
It is not completely unheard of for some concrete companies to throw some wood in the mix. Remove it as everyone has said and patch it with grout or a concrete patch material. Hopefully its just a grade stake as everyone has said.
Very important that you listen to everyone's advice. It is crucial that the wood be removed then patched over. Moisture in your flooring can lead to server problems, that no one wants to deal with.