Here's how I've heard it has been over the years.
Initially, there was no surface treatment on the facade. It was simply too expensive or not even available. The wood grays over time and can endure quite a few seasons without it... When paint materials became available, people started painting houses, primarily to show that they could afford it... So farm buildings, cottages, etc., were not painted. I'm not saying you shouldn't paint, just want to spark a thought.
When painting with distemper paint, the facade should remain unpainted for a season or two. This is more important the finer sawn the wood is. The reason is that the wood needs to rough up and provide something for the paint to adhere to. Those who have tried painting lacquer or distemper on new, planed wood probably understand what I mean... Iron vitriol is to be regarded as distemper. We were "told" by a paint dealer that it is more like cosmetics than actual wood protection. Compared to red paint, some chemical components that supposedly protect are missing... We painted with an Alcrol stain called 206 Silver Gray. Unfortunately, it's discontinued, but we thought it was an alternative to iron vitriol.
It's hard to comment on the color, it supposedly depends on the wood's own properties. And iron vitriol is more or less greenish. I'm not opposed to iron vitriol, on the contrary!! Will probably paint the boathouse with it eventually.
But I wanted to share what we've learned.
The maintenance is simple. Brush off, apply the wash. Just like red paint. And periodicity... As you see fit. Maybe every 5-15 years, depending on which direction it's facing?
Initially, there was no surface treatment on the facade. It was simply too expensive or not even available. The wood grays over time and can endure quite a few seasons without it... When paint materials became available, people started painting houses, primarily to show that they could afford it... So farm buildings, cottages, etc., were not painted. I'm not saying you shouldn't paint, just want to spark a thought.
When painting with distemper paint, the facade should remain unpainted for a season or two. This is more important the finer sawn the wood is. The reason is that the wood needs to rough up and provide something for the paint to adhere to. Those who have tried painting lacquer or distemper on new, planed wood probably understand what I mean... Iron vitriol is to be regarded as distemper. We were "told" by a paint dealer that it is more like cosmetics than actual wood protection. Compared to red paint, some chemical components that supposedly protect are missing... We painted with an Alcrol stain called 206 Silver Gray. Unfortunately, it's discontinued, but we thought it was an alternative to iron vitriol.
It's hard to comment on the color, it supposedly depends on the wood's own properties. And iron vitriol is more or less greenish. I'm not opposed to iron vitriol, on the contrary!! Will probably paint the boathouse with it eventually.
But I wanted to share what we've learned.
The maintenance is simple. Brush off, apply the wash. Just like red paint. And periodicity... As you see fit. Maybe every 5-15 years, depending on which direction it's facing?
All paint that contains pigment provides protection against the sun's UV radiation. That is the main reason one should paint walls (aside from aesthetic reasons). If you have timber of really good quality (densely grown), it lasts longer, whether it is painted or not. But poorer quality timber does not last many years in a southern exposure if it is not painted with some sort of pigment. Apart from covering paints (latex or oil paint), glazes, or distemper paints, you can also paint with tar.
http://www.lansmuseum.a.se/byggnadsvard/byggfarg.cfm?in_idnr=47
http://www.lansmuseum.a.se/byggnadsvard/byggfarg.cfm?in_idnr=47
Linseed oil colors such as red paint and iron vitriol contain toxins that make it less hospitable for fungi compared to an unpainted surface. If the façade is allowed to dry out properly between rains, it doesn't matter, but if it is more humid with stagnant air, it becomes more important.
Cedar is a great material, with strong natural rot resistance. I was involved in the construction of a gymnasium where the facade was partially clad with cedar - expensive expensive, but stylish and good. The question is how it suits a villa since it has a slightly special color.
I don't have much faith in lark. According to studies, lark is only slightly better than, for example, pine in terms of rot because lark has a higher proportion of heartwood. Pine heartwood is just as durable, the sapwood is inferior.
Many in this thread talk about having pine facades, which I find strange, but maybe you know something I don't know :
What I know is that spruce is used for 99% of exterior paneling because its pores don't let in water like pine's do. Among other reasons, spruce is not pressure-treated, as the impregnation fluid does not penetrate.
I don't have much faith in lark. According to studies, lark is only slightly better than, for example, pine in terms of rot because lark has a higher proportion of heartwood. Pine heartwood is just as durable, the sapwood is inferior.
Many in this thread talk about having pine facades, which I find strange, but maybe you know something I don't know :
What I know is that spruce is used for 99% of exterior paneling because its pores don't let in water like pine's do. Among other reasons, spruce is not pressure-treated, as the impregnation fluid does not penetrate.Thermowood is, as the above speaker mentions, kiln-dried and in this way (don't ask me how) has gained a rot protection comparable to pressure-treated timber as well as better dimensional stability than regular undried boards. My experience with Thermowood is that the timber was unattractive (I believe it is made from pine) with an awful lot of knots. If you use a covering paint, this might not matter as much, but knots have a tendency to discolor the paint.
Anyway, if you're interested in Thermowood and Cedar, I think you should call Finnforest (located in Malmö) as they sell these products. As usual, one should not forget that they might not be entirely impartial when discussing their products.
Anyway, if you're interested in Thermowood and Cedar, I think you should call Finnforest (located in Malmö) as they sell these products. As usual, one should not forget that they might not be entirely impartial when discussing their products.
Whether heat-treated wood has any increased rot protection is currently uncertain; it was a marketing gimmick that the Finns later retracted. In any case, you cannot compare the protection with pressure impregnation. However, it has higher form stability, looks brown, and smells like an old sauna ;D