I'm planning to build a patio and thought about using pressure-treated pine in the recommended classes. Nothing unusual about that.
I've been advised not to buy the cheapest options available at the hardware stores and to buy something of higher quality. But where can I find such options? Any tips on a specific dealer in the northern Stockholm area?
I've been advised not to buy the cheapest options available at the hardware stores and to buy something of higher quality. But where can I find such options? Any tips on a specific dealer in the northern Stockholm area?
Beijer Bygg has had all the classes, but whether they still stock them, I don't know. However, they do write about which classes exist and how they should be used, which perhaps can be interpreted as that they can at least order them upon request.
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Below clipped from: http://www.beijerbygg.se/templates/BB_ByggradListItem.aspx?id=12066
Wood protection class NTR/M is mainly intended for structures in seawater on the west coast but can also be used in soil or water where particularly high demands are placed on durability and strength, such as for foundation piles.
Wood protection class NTR/A is intended for wood in permanent contact with soil or freshwater, as well as in structures, even above ground, where personal safety requires that they are not weakened or difficult to inspect and replace.
Wood protection class NTR/AB is intended for wood exposed to weather or condensation, but not in contact with soil or water, where the replacement of damaged parts or personal safety is not of critical importance.
Wood protection class NTR/B is intended for external joinery such as windows and doors.
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magentis.
PS. Spruce cannot be pressure-treated, so everything sold is pine. DS.
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Below clipped from: http://www.beijerbygg.se/templates/BB_ByggradListItem.aspx?id=12066
Wood protection class NTR/M is mainly intended for structures in seawater on the west coast but can also be used in soil or water where particularly high demands are placed on durability and strength, such as for foundation piles.
Wood protection class NTR/A is intended for wood in permanent contact with soil or freshwater, as well as in structures, even above ground, where personal safety requires that they are not weakened or difficult to inspect and replace.
Wood protection class NTR/AB is intended for wood exposed to weather or condensation, but not in contact with soil or water, where the replacement of damaged parts or personal safety is not of critical importance.
Wood protection class NTR/B is intended for external joinery such as windows and doors.
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magentis.
PS. Spruce cannot be pressure-treated, so everything sold is pine. DS.
I was a bit unclear. Finding the material in the right impregnation classes doesn't seem to be that difficult, but what I'm looking for is to find it in good quality.
I have no idea about the difference in quality between different stores, so I hope you here at byggahus can help me with that.
I have no idea about the difference in quality between different stores, so I hope you here at byggahus can help me with that.
There should not be any difference, as it is class-divided. Unfortunately, I have a feeling that compliance is a bit hit or miss... Personally, I only buy pressure-treated wood from ByggMax, after once receiving complete rejects timber from Silvan... But whether they are better or worse than anyone else, I don't know..., but what I have used has at least not been terrible. The downside is probably that ByggMax has such a high turnover of treated wood that it has been "pressed" so recently that it is often both wet and therefore very heavy 
magentis
magentis
Yes, it will look pressure-treated, but the fibers/composition of spruce do not work for pressure treating. Therefore, it is essentially useless to pressure-treat spruce; it does not become better than regular painted rot protection. You can probably find a more technical explanation on the Internet; I just know it is so, and I can't give a better answer.ArneTW said:
Or maybe I'm wrong, and someone has found a good way to impregnate spruce...maybe I need to look into it, so I'm not stating things that are no longer true...
magentis
I realized that there is a sawmill outside Falun (there are probably more) that only saws Larch trees.., at least it used to. Get a couple of boards from Larch to avoid the rot problem on the ridge boards.
magentis.
magentis.
It still seems to be the case, judging by the following SLU thesis:magentis said:
http://ex-epsilon.slu.se/archive/00002766/
Quote: "....the spruce only receives superficial protection because its wood has limited capacity to absorb impregnating liquid (Nilsson, T. & Björdal, C., 2006)."
Diversearbetare
· Göteborg
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That's correct. The sapwood cells of pine have cross-links that allow the treatment to penetrate. The cells of spruce do not have this, which means the treatment stays on the surface. A bit like marinating chicken fillets with oil; it doesn't work.magentis said:
The quality of pressure-treated wood (not the wood protection class) depends on two things: where the timber was grown and the size of the dimension it was taken from.
If you can find slow-grown pine (preferably grown in Norrland, but some imports from our northern neighbors and Russia can also suffice), it is preferable in most cases over southern wood, grown in the Småland highlands. (More suitable for making airplane propellers than for construction purposes.)
If the timber is taken from larger pines with a large trunk diameter, it is better than that taken from a smaller trunk diameter. The difference can be seen in the curvature of the growth rings in the end grain. (As straight as possible is the goal.) And if you find wood with growth rings across the flat side of the timber, you can almost bet 17 times that it's slender pine that has been sawed through and pressed = the worst kind of timber.
In almost all cases, pressure-treated timber is taken from small trunk diameters. It is also never heartwood, only sapwood, because the heart cannot be pressure-treated due to too high resin content.
It is therefore almost as good to use Norrland-grown heartwood of pine for constructions that are not too exposed to moisture as using poor-quality pressure-treated wood.
The alternative: heat-treated timber is a much better protection than pressure-treated.
Addition: your question: where can I find higher quality? The answer is: turn to a lumber yard. If you lived here on the west side, I would have referred you to Högströms Trä in Svanesund.
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Byggaren
If you can find slow-grown pine (preferably grown in Norrland, but some imports from our northern neighbors and Russia can also suffice), it is preferable in most cases over southern wood, grown in the Småland highlands. (More suitable for making airplane propellers than for construction purposes.)
If the timber is taken from larger pines with a large trunk diameter, it is better than that taken from a smaller trunk diameter. The difference can be seen in the curvature of the growth rings in the end grain. (As straight as possible is the goal.) And if you find wood with growth rings across the flat side of the timber, you can almost bet 17 times that it's slender pine that has been sawed through and pressed = the worst kind of timber.
In almost all cases, pressure-treated timber is taken from small trunk diameters. It is also never heartwood, only sapwood, because the heart cannot be pressure-treated due to too high resin content.
It is therefore almost as good to use Norrland-grown heartwood of pine for constructions that are not too exposed to moisture as using poor-quality pressure-treated wood.
The alternative: heat-treated timber is a much better protection than pressure-treated.
Addition: your question: where can I find higher quality? The answer is: turn to a lumber yard. If you lived here on the west side, I would have referred you to Högströms Trä in Svanesund.
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Byggaren
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