As long as twp finish has exposure to the sun it will be fine for both projects. TWP requires uv on it to set up in a timley manor. Ipe will be fine for both projects as well, I am not understanding the question the man has far as the sunroom goes. I do not recomend using the clips to fasten ipe x 10 with the pregrooved, I have several decks out with T&G ipe doing just fine. J

oski, No matter what you do, it will go gray before long, unless it's in total shade. I always seal my decks with Penofin (western red cedar formula). steve

You have pretty much anwsenerd your own questions. With all of the above being true there is no need for further torking down the fasteners. J.

Take a cup of water. Throw it on the (upright) stone. If it falls off without wetting the stone, it's likely soapstone. On a flat (horizontal) piece it'll make a mounded shape and not spread. If it trickles down the (vertical) stone and/or leaves a wet spot, if it flattens on a horizontal piece, it's probably not soapstone. I've never seen soapstone less than 3 cm thick. Serpentine is often 2 cm, though it could be 3 cm. Oil doesn't soak into soapstone. It kind of sticks to the top. Soapstone is oliophilic--it attracts oils. If you take a dab of butter and smear it on with your thumb, it should stay. When you wash it, especially with a bit of grease cutter, it should come right off. I have serpentine in my master. It looks and feels more like marble, and is often classed with marbles, though it's a bit harder. Very veiny. Your translucent ones (the top two) might just be serpentine, on looks. They don't look soapstoney to me. Oh! Another test! If there's powder where it's cut, that feels like talcum powder (i.e., if there's loose talc), it's a sign you have soapstone. Soapstone is composed mostly of steatite and talc, with veins of quartz. I don't know that I've handled an unpolished cut of serpentine, but most crystaline stone dust feels more sand like. Wikipedia says "Most serpentines are opaque to translucent, light (specific gravity between 2.2Â2.9), soft (hardness 2.5Â4), infusible and susceptible to acids. All are microcrystalline and massive in habit, never being found as single crystals. Luster may be vitreous, greasy or silky. Colours range from white to grey, yellow to green, and brown to black, and are often splotchy or veined. Many are intergrown with other minerals, such as calcite and dolomite." Soapstone is heavy. At least mine is. Susceptible to acids suggests another test. Lemons or vinegar might be interesting. Soapstone isn't crystaline, it has platelets or something, so it's not brittle like granite, and doesn't need a lot of support.