SE540654C2 - Design elements and method for making them - Google Patents

Abstract

Construction element (1), with reduced thermal conductivity and with reduced risk of rot, mold and the like and with improved fire protection, comprising at least one elongated object (2) of wood with a first side (3) with at least a first opposite side (4 ) and at least one second side (5) with at least one second opposite side (6) and a first end and a second end. The elongate object (2) comprises a plurality of holes in the substantially transverse direction of the wood fibers, and that the volume of the holes constitutes 20 to 80 per cent of the volume of the elongate object (2). The holes form at least one transverse row (11) and at least a first adjacent transverse row of holes (12) which are offset from each other. The wood material in the construction element (1) is impregnated. The present invention also relates to a method of manufacturing the structural member.

Description

Technical element The present invention relates to a construction element and a method for manufacturing the construction element in accordance with the claims.

Technical background and known technology Throughout the ages, a number of different types of construction elements for the construction of buildings have been developed. Traditionally, wooden construction elements such as logs, boards, joists, planks and the like are used together with other materials for buildings' climate shells. However, using wooden construction elements causes a number of different problems. Wood, for example, has a relatively high thermal conductivity and it can thus be difficult to achieve good thermal insulation in the climate shell. Wood materials in building structures have problems with moisture absorption. In the long run, all moist wood is broken down by microorganisms, which can cause a number of different problems, which are described in the following. Furthermore, wood materials are relatively sensitive to fire.

Craftsmen skilled in the art learned early on to use mature winter-felled timber for the climate shells of wooden houses. Only mature, well-dried wood was used for exposed parts of the houses' climate shells. The industrialized construction has difficulty in making a similar sorting of timber because a skilled craftsman or special equipment is needed to see the difference between sapwood and heartwood in dry spruce timber. Mature wood that is often called heartwood consists of inactive cells where the openings between the cells are closed, which makes water transport more difficult. Water is difficult to penetrate in the tangential but especially the radial direction. Therefore, it is almost impossible to press impregnation deep into mature wood. In end wood, on the other hand, there is a certain absorption of liquid and therefore almost all wood can be impregnated a bit into the fiber direction via end wood, even though it is much slower in heartwood compared to sapwood. Moisture damage to wood usually waves from end wood and especially when end wood from sapwood, without impregnation, is exposed to moisture.

Heartwood from pine contains more resins and it is possible, with the naked eye, to see the difference between sapwood and heartwood. The sapwood of conifers has low durability and it contains more water and hemicellulose. These sugars attract microorganisms and insects. In buildings, wood absorbs moisture and water if it is exposed to moist air or directly wet as condensed water or rain. Wood absorbs water at least 20 times faster in the fiber direction than the tangential fiber direction and when the moisture ratio rises above 20%, wood is attacked by rot fungi and other microorganisms.

During parts of the year, the moisture content is critically high for most wooden buildings and especially where wood is combined with materials that do not absorb as much moisture as, for example, mineral wool. The walls of the well-insulated houses do not get as warm as the frames of the former log houses became. The coldest parts also become the wettest. The ability to absorb and release moisture varies between different types of wood and must be considered when using different types of wood for different purposes.

Insects can also attack wood, even if black ants, for example, prefer moist organic insulation material such as EPS. Mice and rats prefer mineral wool where they can completely destroy the insulating ability of the climate shell in a short time. The combination of moisture and the droppings they leave behind is especially favorable for microbiological growth. When organic material is broken down, a number of substances emit harmful to human health, which in some cases have come to be known as the sick house syndrome. The only safe way to decontaminate infested areas is to replace all infested material and try to build drier or more moisture-resistant structures, which always becomes expensive.

Methods for improving the wood's resistance to the aforementioned problems with rot have been developed over time. Processes for charring wood, as well as heat-treating wood, have been around for a long time. When wood has been heated, it no longer absorbs as much moisture, this applies both across the fiber direction and along the fibers. As an example, therefore, poles that are to stand with ground contact have been charred since time immemorial.

When wood is exposed to temperatures above one hundred degrees, changes occur in the chemistry of the wood, which means that much of the hemicellulose is broken down and makes the wood less attractive to microorganisms, rot fungi and the like. The wood is thus not rot-protected, but it has a further improved protective effect against decomposers due to lower moisture content. The technical / physical properties of wood are also affected to varying degrees. After a certain time at two hundred degrees, the wood acquires a brownish color, which relatively quickly changes to a grayish tone when exposed outdoors. It becomes more brittle than untreated wood, and the strength is significantly reduced. On the other hand, the compressive strength across the fibers is not significantly affected.

Another way to protect wood is to impregnate it in different ways. A number of impregnation methods that are harmful to nature have been developed with an environmental impact as a result. A more environmentally friendly impregnation method consists of impregnation of so-called water glass. Water glass has long been used as a fire protection and wood preservative. For example, treatment of wood with water glass is already known via the patent specification US63618. The problem with water glass is that it is water soluble when used on wood. The impregnation leaches out and is rinsed off with rainwater. The water glass impregnation must therefore be made insoluble and hardened when it is repeatedly exposed to water.

Water glass can be prepared by fusing quartz powder (silicic acid) and appropriate amounts of potash or soda. When the compound is heated, a melt is formed which is water soluble. The melt is diluted with water to desired concentrations. Sodium (baking soda) and potassium (potassium) water glasses are mainly used. Water glass is mineral, odorless, open to diffusion and no hazardous substances are emitted from the liquid glass or after it has hardened. Water glass has a high Ph value. Calibrated glass is preferably used in paint production and the cheaper soda water glass or a combination of the two will be used in the present water glass impregnation. Preferably, sodium silicate, commonly referred to as soda water glass, is used.

Via the Swedish patent SE535622, by applicant Organowood, a variant of an environmentally unfriendly wood treatment method is described. Sodium silicate is preferably used in the process. The intention is to prevent rot, fungal mold or the like. The method describes how the water glass can be made stable and insoluble in water and then used for impregnation. By polymerizing sodium silicate monomers into long polymer chains, sodium silicate is made insoluble. When sodium silicate solution is acidified, this reaction takes place and Organowood has developed a method with a small addition of an acid in the aqueous solution in order to make it easier for the water glass to become insoluble. The patent describes that acid is added to the aqueous solution so that it is close to the gelling point. The solution is then still stable during storage and when it is applied via dipping or showering of the wood material. Agents that affect the viscosity are also added. The solution is then pressed into the fibers using a proven vacuum / pressure impregnation method and then dried and cured.

The technique described in patent specification SE535622 differs to a large extent from the construction in accordance with the present patent application. The patent specification does not describe a structural element in accordance with the present patent application. Furthermore, nothing is written about wood being dipped or showered in a traditional water glass solution without additives where only the concentration of sodium silicate in the solution varies but where the solution is acidified by carbon dioxide after the water glass solution has been sucked into the wood. Without vacuum or pressure impregnation methods.

Other existing methods are to first impregnate with water glass, dry and in a second step use an acidic solution. Additional two-step solutions are available. Despite the fact that vacuum and pressure chambers are used in the impregnation, it is still difficult to penetrate through the annual rings, especially in mature wood. Drying with two-step solutions makes the method time-consuming and expensive. The method in accordance with the present patent application with penetrating rapid penetration without vacuum / pressure chamber even at coarse dimensions and that drying and insolubility takes place in one step via carbon dioxide makes the technology differ greatly to these methods.

Via the international patent application WO20110904418, a variant of building technology is known in which building elements are provided with grooves in the longitudinal direction. In an alternative embodiment, it is also described that the elements have been treated with impregnating agents. The technique described in the patent application differs substantially from the construction in accordance with the present patent application. For example, the construction has lower dimensional stability. It has a plywood layer on both sides of the wall and for thicker wall constructions also a board in the middle. It does not join in a similar way and has longitudinal grooves and not closed cells where end wood is exposed. Should it be impregnated with water glass, this impregnation takes significantly longer because the impregnation must penetrate perpendicular to the fiber direction. The penetration across the fibers is so slow that pressure impregnation is required to make this method work. Nothing is written about drying method, temperatures or anything about making the impregnation agent insoluble.

In the present patent application, the impregnating liquid is sucked in via end wood which is exposed in the boreholes and where neither vacuum nor pressure chamber is needed to cause the liquid to penetrate, even into heartwood. The water glass is dried and made insoluble in one step according to a new method. The object of the present patent application is to create a construction element and a method for manufacturing the construction element which solves or reduces at least one of the above-mentioned problems. The object is achieved with a construction element and a method for manufacturing the construction element in accordance with the claims.

Brief Description of Figures In the following detailed description of the present invention, references and references to figures will be made. These figures are briefly described in the following list of figures. The constructions shown in the figures consist of exemplary embodiments of the invention in accordance with the present patent application. Note that the figures are schematic and that the details can be omitted in them.

Figure 1 shows a first embodiment of the present construction element seen in perspective obliquely from above.

Figure 2A shows a cross section of construction elements according to Figure 1.

Figures 2B to 2D show cross-sections of alternative embodiments of the construction element.

Figure 3 shows a part of one of the simplest forms of frame which is built up of construction elements.

Figure 4 shows a wider variant of the frame built up of construction elements.

Figure 5 shows a frame with intermediate material layers with transverse fibers.

Figure 6 shows a cross section of frame in accordance with Figure 5.

Figures 7A and 7B show a construction element with at least one cover layer having standing annual rings.

Detailed description of the invention With reference to the figures, a construction element 1 and a method for manufacturing the construction element 1 will be described in detail. The construction element 1 comprises in the exemplary embodiments of an elongate object 2 of wood. In alternative embodiments (not shown in figures) the structural element 1 comprises the structural element 1 of some other type of wooden object having a shape other than an elongate shape.

The elongate object 2 can for instance consist of a rule, plank, beam or the like. The wood in the elongate objects 2 preferably has a fiber direction which extends in the longitudinal direction of the elongate objects 2.

The shape of the elongate articles 2 may vary within the scope of the scope of the present invention. In the exemplary embodiments, the elongate objects 2 have a square cross-section, or substantially square cross-section, which is preferably rectangular, square or is of another shape suitable for the purpose. In the exemplary embodiment, the elongate objects comprise at least a first side 3 and at least a first opposite side 4 to the first side 3. The elongate objects further comprise a second side 5 and a second opposite side 6 to the second side 5. The elongate objects 2 further comprises a first end (end) 7 and a second end (end) opposite to the first end 7.

To reduce the thermal conductivity of wood, a large number of holes are drilled in the elongate objects 2 (construction elements 1) such as the joists, planks or the like. Preferably, the holes are 5 - 50 mm in diameter depending on the dimensions of the construction element. In alternative embodiments, the holes may be of a different dimension that deviates from specified ranges.

Referring to Figure 2A, it is shown that the holes are bottom holes 8 which are not continuous but a remaining layer 9 is saved on one side. In the embodiment of Figure 2A, the remaining layer 9 consists of an unbroken layer. The holes are taken up so that the remaining layer consists of material closest to the core. This is to get standing annual rings and maximum heartwood, which contributes to the dimensional stability. The thickness of the remaining layer 9, and the depth of the holes, respectively, can be varied.

When drilling the holes 8 in the elongate objects 2, the longitudinal fibers along the sides and the underside are left untouched, i.e. the outermost layer of material is not broken by the holes.

In alternative embodiments, at least one of the holes may be a through hole 10, through holes are shown in Figures 7A and 7B.

Referring to Figures 2B and 2C, embodiments are shown in which the holes have been drilled from two opposite sides. In the figure, these are drilled from sides 3 and 4. In figure 2B, the remaining layer 9 consists of a partially broken layer. Through construction, part of the dimensional stability is maintained on both sides that are drilled (the surface of the boreholes is distributed on both sides).

The bottom holes 8, and any through holes 10, respectively, can be drilled (milled) in different patterns, such as in honeycomb-like patterns (but with round holes instead of hexagonal ones) where adjacent rows of holes are offset from each other as shown in Figures 1, 3 and 4. In the figures mentioned, it is shown that row 11 and adjacent rows 12 are offset relative to row 11.

Referring to Figure 2C, alternative embodiments are shown in which the unbroken remaining layer 9 is located at a distance from one of the sides 3 and 4. The construction elements 1 (the elongate objects 2) are thus drilled from both sides with an unbroken layer 9 in the middle. The left part of the figure shows an embodiment where the remaining layer is placed in the middle, or essential center of the construction element. In the alternative embodiment shown in the middle part of Figure 2C, the remaining material layer is placed closer to one of the sides 3 or 4.

In further alternative embodiments, shown in the right-hand part of Figure 2C, at least one sub-area 13 of the construction elements 1 (the elongate objects) 2 is undrilled (not machined) or only partially machined (drilled). The size of the part (portion) 13 in relation to the construction element 1, as well as the location of the part 13, may vary. The part (portion) 13 can, for example, be used for attachment or for assembly.

The part 13 may also comprise fewer holes per unit area and / or have holes which are substantially shallower than holes in other sub-areas of the construction elements 1.

The end wood 1 (the elongate object 2) of the construction element 1 is left untouched, i.e. holes extending to the edge are not drilled. In the preferred embodiment according to Figure 1, holes 11 and 12 have already been drilled (milled) after two rows, all longitudinal fibers except a thin layer on three of the sides have been cut. Between 20 - 80 percent of the wood is removed in this way. The volume of the holes constitutes 20 to 80 percent of the volume of construction elements.

In preferred embodiments, about 45 to 55 percent of the wood is drilled away. The volume of the holes is 45 to 55 percent of the volume of the structural elements. In a particularly preferred embodiment, 50 percent of the wood is drilled (milled) away, which means that the construction elements 1 (the wood) thereby reduce to half their weight after drilling. The volume of the holes constitutes 50 percent of the volume of structural elements. Due to the surface enlargement of the construction element 1 (via the surfaces in the holes 8) and the reduced volume of wood, the time required for heating and drying of the construction element 1 is reduced.

Once the holes 8 in the structural elements 1 have been drilled, to the intended extent as previously mentioned, they are dipped or showered in a silicate solution and then dried and sometimes cured. The drilled and impregnated structural element 1 is then laid on top of each other and glued together. The construction elements 1 thus regain their stability when the drilled side is glued with the next construction elements 1 cohesive layer. The reduced surface area, which remains on the structural elements 1 after the holes have been drilled, at the same time increases the element's compliance with the substrate. It will be easier to bend and turn the construction element until gluing. This means that the pressing pressure, when the construction elements 1 are glued, can be reduced to one third or lower.

Referring to Figure 3, it shows a part of a frame consisting of the construction elements 1 which have been joined together, for example by gluing. The figure shows three horizontally directed construction elements which are joined to each other with a width of a construction element. The frame is made up of an arbitrary number of structural elements at an arbitrary number of vertical levels (turns). Joints between structural elements on two adjacent vertical levels are offset from each other. In alternative embodiments, the frame may be built up of structural elements with a direction other than horizontally directed such as vertically directed or another direction suitable for the purpose.

Referring to Figure 4, a portion of the body comprising several layers (turns) of horizontally directed structural members is shown. The thickness of the frame can be varied depending on the number of structural elements 1 (the elongate objects 2) placed in width with each other in each turn (vertical level). The longitudinal joint 14 is covered by an overlapping construction element. Preferably, the construction elements 1 are placed so that a longitudinal space 15 to the next construction element is obtained. The gap 15 breaks the cold bridges, which in turn leads to improved insulation capacity. The frame is made up of an arbitrary number of structural elements with an arbitrary number of vertical levels (turns). Joints between the structural elements on two adjacent vertical levels are offset from each other. The construction provides a finished frame of wood that contains closed cells and where all wood can be impregnated with difficult-to-dissolve water glass throughout.

Referring to Figures 5 and 6, there is shown a frame (a composite structural member) comprising two or more structural members 1 in width. Furthermore, the body comprises at least one material layer 16, with transverse fiber direction in relation to the longitudinal direction of the construction element 1, between at least two layers of construction elements. The intermediate material layer 16 may be located between each vertical layer of construction element 1. In alternative embodiments, two or more layers of construction element are placed between at least a first material layer 16 and at least a second material layer 16. Figure 6 shows a cross section of the construction according to Figure 5.

Referring to Figures 7A and 7B, structural members 1 are shown which comprise at least one covering material layer 17. The covering material layer 17, preferably consists of a layer of material with standing annual rings (in the vertical direction). The construction element and the bearing, alternatively the bearings, material form a beam. The material layer with standing annual rings means that impregnation penetrates more easily at the same time as the dimensional stability is improved. The thin material with standing annual rings is impregnated in the same way as the construction element. Wood shrinks and swells significantly less in the radial direction compared to the tangential direction. Figure 7A shows an embodiment with bottom holes and a covering material layer 17. Figure 7B shows an embodiment with through holes with two covering material layers 17.

It is already known to use water glass to give wood protection against microbiological growth and protection against pests. The impregnation also gives the planks better fire protection.

This invention describes a new method for reducing the thermal conductivity of wood in structural elements. The method is to create closed cells in the construction elements and the wood must therefore be protected against the increased risk of insect infestation.

Water glass has long been known to provide microbiological protection against pests. By impregnating the construction elements 1 with water glass, they also get a better fire protection, which is also known from before. The construction elements 1 are impregnated by a silicate solution rapidly sucking into the fiber direction and then being dried and made insoluble in a new way.

If wood is used as cladding outdoors, especially end wood that is exposed to water must be sealed because water is sucked far into the wood along the fiber direction. This property is used via a new impregnation technology where the construction elements are impregnated in an environmentally unfriendly manner with water glass.

Bottom holes are drilled in different patterns, for example in honeycomb patterns. The holes are made with a drill, cutter, hole saw or similar tools. Through the bottom holes drilled in the construction elements, the end wood of the timber is exposed inside the boreholes. When the drilled structural elements are dipped or showered in an aqueous solution, the solution is immediately sucked into the wood along the fiber direction, which is at least 20 times faster compared to the perpendicular penetration. Since the penetration in the fiber direction takes place from two directions, the time required is further halved. No additives are needed that change the viscosity of the aqueous solution and it is possible to impregnate coarse construction elements throughout without pressure and vacuum chambers.

With known methods, spruce, heartwood and wood rich in resins are usually not suitable for penetrating pressure impregnation. This is due to the fact that it is difficult to push in impregnation across the fiber direction. Said problems are eliminated, or substantially reduced, by the construction of the present structural element due to the holes in the structural element projecting the end wood whereby the impregnation quickly penetrates into such wood even in coarse dimensions. There, the equilibrium moisture ratio is reached with air that has 100% relative humidity. Then the free water between the cells is gone while the cells are still unaffected and a large part of the water in the cell is chemically bound. As the drying process progresses, some of the chemically bound water also dries. Then the wood shrinks and changes shape, which means that the finished wood should have a moisture content that corresponds well with the moisture content of the finished building construction.

Timber to be impregnated should be as dry as is practically and economically possible as impregnation cannot penetrate where the wood is already saturated with water. With the present method and the construction elements, the drying of the construction element 1 is facilitated by the boreholes providing a shorter path for moisture transport and almost all transport takes place in the fiber direction. In addition, the boreholes may have removed more than half the volume of wood and increased the surface. Due to the construction of the construction elements 1, the moisture transport does not have to take place in the transverse direction to the fiber direction in the construction element 1, whereby the drying requires a smaller time.

There is a risk of microbiological growth in untreated wood from about 20% moisture content and upwards. Timber that is temporarily exposed to water should therefore have a hydrophobic surface or be protected in some other way. The impregnation must also not be water-soluble so that it is rinsed off by water. Water glass in wood that has not been made insoluble is such an impregnation and therefore the impregnation must be made insoluble when the beam is to be used in an outdoor environment.

The construction elements 1 are dipped in a silicate solution. The elements remain in the solution for the required period of time required for the silicate solution to have time to absorb into the heartwood of the elements (the heartwood needs twice as long to absorb the silicate solution compared to the sapwood). After that, the surplus must drain off. The solution remains in the wood as long as the relative moisture ratio in the ambient air (gas mixture) is 100%. Preferably kept, the ambient air (gas mixture) has an elevated content of carbon dioxide. Alternatively, the carbon dioxide content corresponds to the air's natural share of carbon dioxide. In this state, the structural elements 1 are kept for a period of time in a space with 100% relative humidity.

The silicate solution is then acidified via the carbon dioxide formed in the aqueous solution when it comes into contact with the carbon dioxide of the air (gas mixture). The holding time is adapted to the temperature the solution gets when it is mixed with cold water, but room temperature or a slightly elevated room temperature is sought. The impregnation of the structural elements 1 is made insoluble by means of carbon dioxide. When flue gases are added to the wood dryer, the carbon dioxide content in the moisture-saturated air increases. The large surface of the structural elements 1 which is projected via boreholes speeds up the process.

When the construction elements 1 are dried, the temperature is raised at a slow rate by means of hot moisture-saturated flue gases. The acidic substances that are formed naturally when wood is heated, together with the carbon dioxide formed in the aqueous solution, keep the silicate solution suitably acidic during the entire drying process. Long polymer chains can then be formed continuously. As the relative humidity ratio decreases, water retention increases at the slowly rising temperature.

The temperature increase continues so that a slow polymerization may reach 100 -120 degrees. The temperature, time and relative humidity ratio of the flue gases determine the amount of bound water that remains in the cells. When the construction elements 1 are calculated to have dried sufficiently, the temperature is raised quickly, less than 10 minutes, to 150 degrees for the water glass to harden. In alternative procedures, the curing time may be 10 minutes or longer and the temperature may exceed 150 degrees. The process is fast because the construction elements 1 surface has been enlarged through the drilled holes and the volume of wood may have been reduced to more than half in relation to the original volume. To avoid self-ignition during drying and curing with flue gases, a lambda probe is used to check that the oxygen content is kept down to a level where the wood does not ignite automatically. When the construction elements 1 are then ventilated for humidification, it will take a long time before the moisture ratio in the wood rises, which is an advantage during transport, assembly and storage.

In alternative drying than with flue gases, the closed drying space is filled with the desired concentration of carbon dioxide. When the temperature then increases, carbon dioxide is gradually added from below. The heavy gas carbon dioxide then displaces the oxygen present in the drying space. The construction elements 1 can thereby not self-ignite, or are difficult to self-ignite. When the temperature rises further via an external heat source, the relative humidity ratio of the air can be controlled via a cold surface where the steam can condense. The construction elements 1 can also be dried in a traditional wood dryer.

The absorption of moisture from ambient air is slower and the impregnated wood in the construction elements 1 also absorbs less water during temporary water exposure compared to untreated wood, which cheapens and makes the construction process safer. Moisture that is absorbed more slowly increases the dimensional stability, which is also good when certain thin layers of wood are glued with the fiber direction 90 degrees at an angle to the underlying fiber direction. Advantages that are achieved are that the finished wall has less moisture movement, thermal conductivity is reduced and the risk of damage by microorganisms is further reduced. Furthermore, the finished construction elements 1 are not as sensitive to temporary moisture as untreated wood and become more fire-resistant.

With the present method, sapwood from conifers and especially young pine wood can be used because it is less resistant than heartwood and absorbs liquid more easily. It is therefore inappropriate to use such wood in exposed parts of the climate shell if it is not impregnated. Defective wood such as reaction wood, wood with resin coatings and large twigs as well. This wood can be drilled and beamed when it is impregnated and glued together. Then it is possible to use these construction elements 1 in different constructions and exposed positions where there are no flexural strength requirements. Said wood is also the cheapest wood.

When the impregnated structural element 1 is dried and the temperature is increased for the water glass solution to cure, the hemicellulose is partially degraded but the high temperatures and long treatment times required for heat treatment of wood are avoided. Reduced amount of hemicellulose in wood is not protected from fungi and microflora, but the wood is not as easily attacked as many tempting ingredients are dried out even at the low temperatures where water glass hardens.

In the detailed description of the present invention, construction details and sub-methods may be omitted which will be apparent to one skilled in the art to the field of the method and device. Such obvious design details and sub-procedures are included to the extent necessary to obtain a satisfactory function. Although certain preferred embodiments are described in more detail, variations and modifications of the method and apparatus may be apparent to those skilled in the art to which this invention pertains. All such variants and modifications are considered to fall within the scope of the appended claims.

In alternative embodiments, impregnating agents other suitable for the purpose, or other suitable impregnation agents than those mentioned in the patent application, can be used in the impregnation. For example, impregnating agents containing metals can be used.

In alternative embodiments of the process, the penetration of the impregnating agent can be accelerated by vacuum and pressure.

Advantages of the Invention With the present invention, a number of advantages are achieved. The most obvious is an improved design element as well as method of producing this is achieved.

Claims (10)

Patent claims Construction element (1) comprising at least one elongate object (2) of wood with a first side (3) with at least a first opposite side (4) and at least a second side (5) with at least a second opposite side (6) and a first end and a second end characterized in that the elongate object (2) comprises a plurality of holes in the substantially transverse direction of the wood fibers, and that the volume of the holes constitutes 20 to 80 percent of the volume of the elongate object (2), and that the holes form at least one transverse row (11), in relation to the longitudinal direction of the elongate object (2), and at least a first adjacent transverse row of holes (12), in relation to the longitudinal direction of the elongate object (2), which rows are offset from each other, and that the wood material is impregnated. Construction element (1) according to claim 1, characterized in that the volume of the holes constitutes 20 to 80 percent of the volume of the construction element (1). Construction element (1) according to one of the preceding claims, characterized in that the holes consist of bottom holes (8) with a remaining layer (9) which consists of material closest to the core. Construction element (1) according to one of the preceding claims 1 and 2, characterized in that the holes consist of through holes (10). Construction element (1) according to at least one of the preceding claims, characterized in that the construction element (1) is covered on at least one of the sides by a material layer (17) selected from wood near the core, so-called heartwood. Construction element (1) according to at least one of the preceding claims, characterized in that the construction element (1) comprises at least two elongate objects (2) which are glued together directly on top of each other, with offset joints. Construction element (1) according to claim 6, characterized in that the construction element (1) comprises at least one material layer (16) with the fiber direction in the transverse direction to the fiber direction of the elongate objects (2). Method for manufacturing structural elements according to at least one of Claims 1 to 7, characterized in that an immaterial is provided after which a plurality of holes are taken up in the wood material in the substantially transverse direction of the wood fibers, then the wood material is impregnated with impregnating agent. remain in the impregnating agent for a period of time which depends on how far into the sapwood or heartwood the penetration of the impregnating agent is desired, then the excess impregnating agent is allowed to drain off after which the structural element is placed to dry in air which is initially moisture saturated and where carbon dioxide is supplied in concentrated form or via flue gases at the same time as the temperature is slowly raised to 100 - 120 degrees, after which the temperature is raised to about 150 degrees so that the material can then be aerated and cooled. Method according to claim 8, characterized in that the impregnating agent consists of water glass. Method according to one of Claims 8 or 9, characterized in that the carbon dioxide content exceeds the normal carbon dioxide content of the atmosphere.