Hi everyone, new member here.
Let's see, where do I begin?... perhaps with a brief summary, and then the whole story?
Summary: Our 8-year-old house (treated with Sansin) is infested with fungus / mold, and Sansin can't help. We want to switch to Sikkens Cetol (I think), and are not sure how to proceed.
Please bear with me with the long story, I do have some questions (at the bottom), and genuinely need some help.
Long story: built our house 8 years ago, and treated it the right way. The logs were clean to begin with, then we had them pressure washed, and then we sanded the whole house (80-grit with palm-sized orbital sanders) from top to bottom just prior to staining (yeah, we really wanted this to work, and were dedicated). We applied two coats of Sansin stain (Natural 011), then one coat of UV Clear, all in the same season (yeah, we were busy). The next summer, we applied a secod coat of UV clear / stain mixture (4 parts UV clear to 1 part Natural 011). Since then, we had to treat the entire house two additional times because the sheen on the UV clear appeared to be worn out. As the suggestion of the supplier of the Sansin products, each time we used the same 4:1 UV Clear:stain mixture.
Then the horror began.
We initially got black dots here and there, then entire patches of those same black dots. The supplier of the Sansin product was not surprised when we called him, and he said it was just fungus (he himself had to treat his log house for fungus almost every summer, or so he claimed). So he suggested using his recipe: 10% household bleach, applied from bottom to top, then rinsed thoroughly. The problem is that this also took off the sheen of the UV Clear, so we treated the whole house yet again, still with the 4:1 mixture. The next spring, the fungus came back... but worse yet, some of the fungus appears to be thriving *underneath* the UVV clear, which means you can't easily get to it. I have attached a jpeg closeup picture that shows that (as best as I could).
We contacted Sansin, and they were no help at all. They had a fresh-out-of-college girl who contradicted herself every time she consulted her senior colleague, and told us to bring it all the way back to bare wood (!!!) and start over with Sansin products. Yeah right, repeat the same mistake we made eight years ago, which brought us to this hellish situation? Thanks, but no thanks. Insanity is repeating the same gestures over and over again, and expecting different results.
A friend of mine had a log home treated with Sikkens Cetol, he owned it for 23 years, and he applied maintenance coats 3 times total over those 23 years. I have already beat him 3-fold, maintenance wise, in just 8 years with this Sansin stuff.
So my questions are:
1-) Other than killing myself at the job of sanding the whole house again (and it will be worse now because of the sticky UV clear coat), is there an environmentally friendly way to chemically "strip" it or neutralize it, just enough to accept a Sikkens coat? Note that we have a well as water supply so we need to be cautious of what chemicals run off to the ground.
2-) When asked, Sikkens tech support told me I can't apply their product on top of Sansin, and that I first have to bring it back down to bare wood (!!!! again!!!). Does that mean only removing the sheen from the UV clear, or all the way through to whichever depth the Sansin stain has penetrated to? This sounds insane... is Sikkens just being overly cautious for liability reasons?
3-) Is Sikkens the right product to use (after the Sansin fiasco)? I only have a single reference, so any advice would be useful. I think I need to worry about breathability, but the logs are 8 years old...
4-) Do I need any additives in the Sikkens to prevent any future fungus growth? Or any tratment to the logs *before* applying the Sikkens?
5-) I read in a forum that the darker stains are better for fungus protection (and therefore, Sansin's Natural 11, which is a caramel color, was a mistake to begin with). Is there any truth to that, and if so, how dark do I have to go?
6-) I have a neighbour in a log house about 500 feet away, and he does not maintain his house. In fact, it is also covered with fungus. Are fungus airborne? I mean, am I condemned to be permanently attacked by fungus because of this source 500 feet away?
7-) After 8 years, I have to assume that the logs are sufficiently dry that I don't even need to worry about it, right?
8-) Or do I have to hope that lightning will strike and burn the darned thing to the ground so I can build a fake one using Canexel?
Any advice would be greatly appreciated... my wife and I worked so hard for that house, we are heartbroken to see it become a burden. If we could only get over this bad spell, we could start enjoying it again, instead of worrying about how much more work it will represent.
Many thanks in advance,