Sorry, I knew it was someone with an M...MathiasS said:
So it's Mathias behind the magical 17 degrees (prime number and all)
Mathias, could you explain the scientific background of the 17 degrees?
For those of us who have forgotten.
PS
We real nerd-amateurs cut each board at 45 degrees and placed them in a bucket with Jotun's Trebitt for a while before installation.
It didn't turn out so straight. But the boards neither rotted nor cracked!
The secret behind the 17 degrees is on the forum. Seek and you shall find.KnockOnWood said:Sorry, knew it was someone with an M...
So it's Mathias behind the magical 17 degrees (prime number and all)
Mathias, can you explain the scientific background of the 17 degrees?
For those of us who have forgotten, that is.
PS
We real nerd-amateurs cut every board at 45 degrees and placed them in a bucket with Jotuns Trebitt for a while before installation.
It wasn't very straight. But the boards neither rotted nor cracked!
Physically speaking, it's probably about surface tension and moisture-releasing surface.JOW said:
The droplet is held together by surface tension so that its evaporating surface area is smaller than the spread-out water from the droplet on a straight-cut surface. A larger area for evaporation gives faster drying.
Additionally, a beveled surface is very difficult to paint properly on-site. Try looking with a mirror after you've painted a board to see how it looks. The thin edge is sensitive to wear, both mechanically from things hitting the bottom edge of the facade and from the impact of weather and time.
I never cut with a bevel again! However, as mentioned, the absolutely most important thing is to make sure to paint carefully, but as said, it usually doesn't turn out well unless you have good conditions with a high base so you can see what you're doing.
Word!Bele said:
I think that's exactly what this is about. It's different when the panel was set flush against, for example, a basement wall like it is on our house. There it has decayed quite extensively after 40 years.
What I think is just as important as the surface treatment is that it's airy around the end wood. Move the board a bit away from the substrate and the nailing rule a bit up. If the panel is finished with a drip edge, there should be a decent amount of air between the edge and the panel, and the edge should preferably be placed behind the nailing rule so there is air even behind the panel end.
I'm writing this just after I've angle-cut all the boards on a wall. Unfortunately, I've failed to get a straight, nice edge and I'm considering bringing out the circular saw. The problem is that the drip edge under the panel protrudes so much that it seems difficult to fit the circular saw. If I place it above, the panel becomes a bit too short. I'll see how it looks when the entire wall is done.
I think it's easy for many to get stuck with "that's how we've always done it," and all new findings are often dismissed as poorly substantiated and arisen to save time. Then someone like Bele often comes along with a reasonable explanation with a bit of scientific perspective.
A simple comparison. If there are drops on a table, do they dry faster if they remain as drops or if you spread them out? Additionally, the tip of the drip-nose also absorbs water, and the wood there is thin and sensitive. Rot, as is well known, is a living organism that spreads if it gets a foothold, which it easily does if the concentration of water is high, as it becomes at the very tip of the drip-nose.
/mats
I am one of those who are a bit skeptical about droppnäsa. I have a house+garage with a 15-degree slope and much of it is in poor condition now, but that's partly due to poor maintenance by previous residents. It seems that the fragility at the tip gives more grip for rot. When I go and check the moisture, it's in the droppnäsa part that there is almost rot everywhere, while above that (about 5mm) is good wood. When shoveling, sweeping, etc., the tip of the panel is easily damaged (I have 5-15cm from the ground), and then the process accelerates. I will probably cut straight and create a "stronger" finish, and of course, aim to do the groundwork with oil and so on as well as possible, and maintain the facade in the coming years. Maybe I should mix it up a bit to see the difference in 30-40 years and then come back here
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· västra götaland
· 372 posts
Anyone have a quick and good tip on how to get the cut panel boards straight at the bottom when nailing them up?
My experience is that on-site cutting is the only sure way to get it perfectly straight. Placing the boards on something when mounting also works, but I think the end result is better with on-site cutting.Andreas Ludde Lundell said: