Cumaru has moderate movement. Not a lot but definitely some. If you have humidifiers/dehumidifers/ac to keep a consisten temperature/humidity through the year that's a good thing. I mentioned this to floorguy before but got no response. Not sure if he is confusing brazilian teak with real teak (tectonis grandis). There is a large disucssion with legal harvestation of real teak - with the sustainable teak being "plantation teak". The best teak(true teak) in the world is from burma. Unfortunately burma and the us don't get along (sort of like cuba) - therefore anything from burma is labeled 'illegal'. Now, not getting into whether its forested correctly or whether the political powers that be in burma are right/wrong but the rest of the world use burmese teak - just not us. We'll use a lot of other woods that are harvested in much worse conditions than burmese teak but because us nd burma are politically at odds - burmese teak is 'illegal'. Brazilian teak is harvested similarly to brazilian cherry - and its whole issues in the brazilian/south american rain forest. they are two distinct woods with the "teak" common name (brazilian teak is not teak, just a common name for us to associate it with a desirable wood that isn't as widely available).

The truth of the matter is ony 40 % of the pre-finished exotic species coming in from S. American are prefinished in this 3rd world country (Brazil) @ ... 60 % comes in he the USA with all 4 sides micro-beveled (MB4) and finished state side then put on the different branded boxes. The USA prefinishers, have proven over the years to be better, and produce a higher quality finish. Most of what you get is 7 coats aluminum oxide w/ a 25 year warranty & a 35 % sheen the Key is getting a clear grade of lumber to start. Buying on line can be tricky as most on line vendors offer low price and sell china style with the random lengths being 1 - 4 BE care as they only say RL. True brazilian style production is RL 1- 7 foot just like USA oak. if a floor is priced $ 1.00 - 2.00 below market there is a reason. # 1 reason is it is short RL 1 - 4 (china production) # 2 is the grade of lumber is not Clear. And remember clear grade is 1st grade / select & better is 2nd grade and select grade is 3rd

Look at the treads to see the condition theyre in. If anything you might only need to hand scuff them with 100g or 120. Then for finish use a water borne urethane. First a sealer then 2 finish coats Before you apply the sealer wipe down the tread with denatured alcohol. This will help remove the surface oils.

Mairin, no wonder I loved the width of your floors. The 4" width is my favorite board width and if I ever meet someone and buy a new home, I want solid 4" width boards. Right now I have 5" wide Engineered BR-111 Brazilian Cherry floors that I love but I still prefer the 4" width the best. I love Teak but I could not find any in the engineered wood when I was looking and I needed that due to living on a concrete slab since my home was built in the preserved wetlands so there can be no basements here. Surprisingly my slab was very dry. I just LOVE your backsplash so much! You have exquisite taste. Thanks for sharing.