Looking for help. Went away for a week and came back to find one of my rooms with real floors has dark water spots. No mold it’s a simple case of water damage. Does anyone have advice / contacts of someone who could come and quote and repair the damage based in Chiang Mai? 

Fix your leaky roof/pipes before you fix the floor.

Not from a leak it was from the maid who put water on the floor.

Try this :

 

 

Soak a clean rag in vinegar and place the rag onto the stain. Allow the vinegar to work into the stain for 5 to 10 minutes. You may need to work in sections for larger stains and apply the vinegar multiple times to see stain lightening.

OR

Mix a solution of four parts water to one part bleach and spray or wipe onto the exposed wood surface. Bleach will lighten the stain with successive applications. If you aren't seeing appropriate results, strengthen the solution and reapply. Sometimes, sanding the surface with fine sandpaper will help release the layers of polyurethane.

 

Just a suggestion you may wish to try yourself. Try in small area first, before applying to all of it.

 

 

 

Yes I would follow a similar method to Charlie.

The initial sanding in the area is the important bit. It removes any existing finish to allow the bleach to penetrate. Use bleach or the wifes hydrogen peroxide and brush it into the stain and leave it overnight.

Another great stain remover is baking soda and vinegar, mix into a paste, infact thats exactly how i make my toothpaste for teeth whitening. Then brush it in with your wifes toothbrush.

Just make sure you see the results of your labour before the wife kills you.