1 Reading the assembling plan
1.1 The assembling code is printed on one of the sides of the profile and helps identify the profile even if, by accident, the packs might untie and mix.
1.2 The assembling code has the form: BR1/HO/G/EX1. Groups of numbers and letters separated by inclined lines, each with its relevance and following the rule: the first group (BR1) is the coding for the name of the profile, the second group (HO), is the coding for the name of the project, the third group (G) is the coding for the name of the level and the last group (EX1) is the coding for the name of the structural element.
1.3 When the designer is doing the coding, he will try (as much as possible) to code in a realistic manner to ease the understanding of the codes. For example, “BR1” would be a bar element, “HO” would be a house, “G” – the ground floor, and “Ex1” – exterior wall 1. Thus we will have bar 1, from the exterior wall one from the ground floor for the project house.
1.4 The code can also have the form BR1/HO/G/EX5(EX1). It means that “EX5” is identical to “EX1”.
1.5 The name of the profile is written on each profile in the drawing is written in the plan of the structural elements.
1.6 The position and name of the structural elements are written on the plan of the levels.
1.7 On the 3D plan, you can understand the position of a structural element for which its position and orientation are not clear on the plan of the levels.
1.8 The correct placing of the structural elements on the foundation is done by correctly placing yourself when reading the plan of the levels.
1.9 We read from the plan the code from left to right, and we imagine ourselves positioned in the face of the panel. On the plan, the writing is on top of the panel, while in reality, the assembling code printed on the profiles must be facing you. (Fig. 1).
1.9.1 The technical documentation will help you to measure and to understand the position of the connection elements and larger profiles included in the project.
2 Sorting of the profiles and structural elements
2.1 Each structural element is formed of one or more packs. To be able to assemble the structural element, you have to find all packs forming the element (written in the packing list).
2.2 For easy sorting, we recommend that from unloading try to sort on elements and levels (as much as space allows).
2.3 First, assemble the elements that are near, formed of one pack, or the ones that you sorted from unloading.
2.4 Do not look through the stacks hundreds of times to find a pack because, as you assemble, you will find the one at some point.
2.5 Sort the pre-assembled elements or the ones that you pre-assemble on levels and as much as possible in the order that will be assembled in the load-bearing structure.
2.6 Place the structural elements with the assembling code facing upwards so they can be easily identified. You can also write with a permanent marker the name of the element on a visible edge.
2.7 If there are many identical elements EX5(EX1), you can place them in stacks and use any of them when needed as it will not make a difference in terms of a structural point of view.
3 Assembling elements
3.1 We use self-tapping screws when assembling Unic Rotarex® profiles, as mentioned in the technical documentation, by introducing them in the existing holes until the material of the two profiles is close to each other, and the head of the screw is hidden in the dimple of the node (Fig. 2)
3.2 For The profiles that have a dimple less than 2 mm close to the cut edge, it is compulsory to introduce in this node a self-drilling screw (4.8×19 Grabber) on each side very close to the dimple on the intersection direction. (Fig. 3)
3.3 Structural elements are connected with self-drilling screws (Fig. 4), as mentioned in the technical documentation.
3.4 We can use concrete screws (Fig. 5) in the situations mentioned in the technical documentation in case of nonstructural elements.
3.5 Connection elements (welded elements) are assembled with the larger cold-formed or laminated profiles with metric screws, as mentioned in the technical documentation.
3.6 Connection elements (L’s and strip elements) and the structural elements are fixed to the concrete with steel anchors (Fig. 6).
3.7 If planar differences on the support are maximum, of 10mm, the steel anchor mentioned in the technical documentation will be used.
3.8 If planar differences on the support are between 10-25mm – the same category of steel anchors will be used, however longer by 30-50mm.
3.9 If planar differences on the support are between 25-50mm and the structure has been leveled by plastic spacers – fixing will be done by chemical anchors by consulting the technical designer.
3.10 It is compulsory to follow the assembling instructions imposed by the technical data of the steel anchors and chemical anchors.
4 Connection elements
4.1 Connection element P1 (Fig. 7) is fixed with self-drilling screws to the steel structure and with mechanical steel anchors or chemical anchors in the concrete slab.
4.2 Strip element P1 (Fig. 8) is attached with self-drilling screws to the steel structure and with mechanical steel anchors or chemical anchors in the concrete slab.
4.3 Welded connection elements (Example Fig. 9) connect big section profiles with metric screws and with mechanical steel anchors or chemical anchors in concrete. Welded connection elements are detailed in the technical documentation.
5 Auxiliary assembling materials
5.1 Connecting sealing tape (Fig. 10) is stuck to the bottom of the profiles that are in contact with concrete, wood, or different profiles than Unic Rotarex® profiles.
5.2 Plastic spacers (Fig. 11) are used when the concrete support on which the structure is fixed is not perfectly leveled. The plastic spacers are placed under the bottom chord near the vertical studs. They have different thicknesses and coupling. Different types can reach the required height level. After fixing, the remaining space must be filled with concrete (sand and cement paste).
6 Tools and assembling accessories
6.1 Drill, considering the significant number of screws, we recommend using a 220V wire drill. You can use a battery drill to fix the roof elements.
6.2 For anchors, use hammer drills with SDS, SDS+ drill bit shank.
6.3 Mechanical clamps are a handy tool to fix the structural elements in position before the final fix with self-drilling screws.
6.4 Bit heads (Fig.13). It is essential to use adequate ones for the screws mentioned in the technical documentation.
6.5 To assemble structural elements, it is enough to use a short bit (25mm) introduced in the drill extension.
6.6 To assemble the structural elements, we recommend using a long bit of 150mm introduced directly in the drill, without the extension.
6.7 We tighten anchors with a torque wrench.
7 Assembling in structural elements
7.1 The structural elements that are bought as flat packs are assembled based on the assembling plan, by fixing the profiles together with self-tapping screws according to the technical documentation.
7.2 Because the elements have different shapes and sizes, they are packed in one or more packs.
7.3 After identification of all packs forming a structural element, their plastic ties are cut, and the profiles are positioned according to the assembling plan of the element on a straight, clean, and dry surface.
7.4 All profiles will be positioned with the assembling code facing up in the place indicated by the assembling plan.
7.5 Each profile is graphically shown on the plan with the thin line representing the lips of the profile and the thick line representing the back of the profile.
7.6 It will be checked that each profile is positioned with the assembling code up, and the thick line on the side symbolized on the plan.
7.7 From fabrication, each node is produced with one end of the profile tightened to be easily introduced in the gap on the other profile. If the tightened end does not fit easily, it can be hit with a steel hammer.
7.8 The order in which the profiles are connected is done in such a way that all profiles can be connected when the last profile is fitted. From inside to the exterior and from one end to another.
7.9 Each profile has two holes in the dimples at each end of the profile. These are designed to fit on top of each other perfectly. A self-tapping screw is introduced in each hole using a drill with the appropriate bit head. The screw is tightened until the dimples and the head of the screw is close to each other.
7.10 After all screws are introduced in the paired dimples. The element will take its designed shape.
8 Positioning or adapting the structure to the foundation or different support.
8.1 The first thing to be done is marking. We recommend that you use stretched strings and spray paint over them.
8.2 For a correct marking, we recommend using optical or laser measuring instruments.
8.3 If you do not have optical or laser measuring tools, for right angles, we recommend using the mathematics right angle method. Meaning that you can determine a right angle by measuring a side of 6 (3) m, one of 8 (4)m, and the hypotenuse should be 10 (5)m.
8.4 A correct rectangular foundation will have its diagonals equal in length.
8.5 Verify differences in height and write them in the marking report.
8.6 If the differences are too significant, ask the structural engineer or the site coordinator for a solution.
8.7 Do not assemble on a foundation that is smaller or way bigger. Ask for an answer from the designer.
8.8 Height differences more significant than 50mm will be solved by the solution given by the structural engineer.
8.9 Consider that always a structure that is correctly assembled will follow millimeter tolerances in the dimensions on plans.
8.10 If the foundation or the support on which the steel structure is positioned it’s not according to the plan, you should decide together with the decision-makers on-site and the structural engineer how to position the structure (or what measures should be taken) on the support considering the new factors.
8.11 On all faces of the profiles that are in direct contact with the support, the connecting seal tape must be stuck (it is recommended to use a rubber band – Rigips type).
8.12 Fixing on the soil or the support foundation is done by using the materials and following the dimensions mentioned in the technical documentation.
8.13 The tightening of the steel anchors is done using a torque wrench until the nut is close to the support.
8.14 If you feel that when you tighten the nut rotation is too easy and the cone does not expand in concrete, you got to verify if the problem is local or generalized on the entire foundation.
8.14.1 When the problem is local, the mechanical anchor that could not be tightened is replaced by a chemical anchor.
8.14.2 When the problem is generalized, you must call the decision-makers (site coordinator, structural engineer, quality assistant) that will give the appropriate solution.
9 Assembling of the structural elements in load-bearing structures
9.1 Assembling of the load structural elements together in load-bearing structures is done following the assembling plans by using self-drilling screws according to the technical documentation.
9.2 For easy access in the position where the self-drilling screws have to be introduced along bit must be used 150mm (Fig . 13)
9.3 The order in which the structural elements are positioned is from bottom to top and from one side to another following a logical arrangement.
9.4 The 3D file will be used when the position of a structural element is not understood from the 2D plan. The 3D software can be downloaded for free from the developer’s website. The 3D model will always edify the position and orientation of the structural elements.
9.5 For “T” or “X” panels intersections where it is difficult to introduce the self-drilling screws, the contact profile from one of the panels will be removed from the panel and will be fixed in position on the other panel. The rest of the panel will then be coupled again with the profile. (Fig.14).
10 Covering the structures
10.1 The structure is modulated from the design phase to the boarding materials.
10.2 Gypsum boards are fixed to the structure following the producer’s instructions using self-drilling screws.
10.3 OSB boards or other similar types of boards are fixed to the structure following the producer’s instructions using self-drilling screws.
10.4 Corrugated steel sheets or sandwich panels are done using the materials specified in the technical documentation.
11 Cuts and holes in the structures
11.1 The structures are delivered with installation holes done during fabrication (if the buyer specifically asked for it and provided a clear installation plan).
11.2 If some holes were not mentioned in the installation plan, it is allowed to perforate a maximum of 3 holes (on a vertical stud), in the center of the profile using a hole saw of a maximum of 32 mm in diameter and a distance of a minimum of 100mm between them.
11.3 It is allowed to cut the flange of the profiles that are in direct contact with the foundation between the vertical studs. Cuts have to be done with a steel scissor. Never use an automated steel saw.
11.4 It is allowed to drill as many 12mm holes as needed in the top chords of the walls or in the profiles that are not subject to compression. The use of the 32mm hole saw in these elements is allowed only if a distance of a minimum of 30mm is left between holes.
11.5 It is forbidden to drill holes in any horizontal or inclined trusses.
12 Work safety
12.1 Use individual protection equipment: safety jumpsuit, safety boots, glows, helmet, safety harness, etc.
12.2 Climb the structures only if you are anchored with belts and harnesses and if scaffolding, mechanized lifting, or ladders are not available on site.
12.3 During winter or in high humidity, the structure is slippery. Step on it carefully using safety shoes with adherent rubber soles.
12.4 After you finish assembling the floor trusses, first cover the structure with the boarding material mentioned in the project and only after move on to assemble the top floor.
12.5 It is forbidden to cover the areas of the floors where the top floor structure will be positioned.
12.6 Because steel is a good conductor of electricity, pay extra attention to cables that are suspended to the structure, which can deteriorate and get in direct contact with the steel and electrocute.
12.7 Do not introduce long bit heads in drill extensions as the coupling becomes eccentric, and accidents become more probable.
12.8 Follow all the work safety requirements specific to a construction site.
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