How is the length of the wooden ceiling beams
Possibility unsupported cover large areas significantly expands the architectural possibilities for the design of the house. A positive solution to the issue of the beam allows you to "play" with the volume of rooms, install windows, build large halls. But if you close the "tree" a distance of 3-4 meters is not difficult, then, to use any of the beam on the span of 5 m and more - it is a complex issue.
Wooden joists - Dimensions and loads
Made hardwood floor in a house made of logs and the floor shakes, bends, appeared the effect of "trampoline"; We want to make wooden floor beams of 7 meters; you need to close the room in 6, 8 meters long, so that does not rely on the joists intermediate supports; what should be the joists in the span of 6 meters, home from a bar; what if you want to make free planning - such questions are frequently asked forum users.
Maxinova (User FORUMHOUSE)
I have a house of about 10x10 meters. On the floor I "threw" wooden logs, their length - 5 m, section - 200x50. The distance between the beams - 60 cm. During operation, the overlap was found out that when children are running around in the same room, and you are standing in another, on the floor there is a fairly strong vibration.
And a similar case is far from unique.
elena555 (User FORUMHOUSE)
I can not understand what beams for intermediate floors needed. I have a house 12x12 m, 2-storey. Ground folded aerated concrete, the second floor attic, wooden, beam blocked 6000h150h200mm, packed every 80 cm. Lags laid on I-beams, which rests on the pillar mounted in the middle of the first floor. When I go on the second floor, you can feel the shaking.
Beams on long spans have to withstand heavy loads, therefore, to build a strong and reliable hardwood floor with a large span, they need to be carefully calculated. First of all, you must understand what kind of load can withstand the wooden lag of one or another section. And then to think, to determine the load for the floor beams, which have to do roughing and finishing flooring; than will be filed ceiling; whether full-floor living quarters and non-residential attic above the garage.
To calculate the load on the joists, you need to lay down:
- The load from the dead weight of all structural elements overlap. This includes the weight of the beams, insulation, fittings, flooring, ceiling, etc.
- Operational load. The operational load can be permanent or temporary.
When calculating the operating load is taken into account the mass of people, furniture, household appliances, etc. Load temporarily increases with the arrival of guests, noisy celebrations, moving furniture, if it is to push the walls in the center room.
Therefore, when calculating the operational load necessary to consider everything - right down to what type of furniture you plan to bet, and whether there is likely to install a sports simulator future.
For the load acting on the wooden beams overlap great length, the following values (to the attic and floor decks):
- For intermediate floors and ceilings of the attic floor total load is taken at the rate of 350-400 kg / sq.m.
- The attic floor - 150 kg / sq.m. Where (SNIP 2.01.07-85), taking into account the safety factor - 50 kg / m - is the load of its own weight of overlap, and 100 kg / m - characteristic load.
If you plan to store in the attic of things, materials and other necessary items in the home, the load is assumed to be 250 kg / sq.m.
What joists span of 4 metersaccepted norms
Most often in the construction of wooden beams and timber planks are used so-called popular sizes: 50h150, 50x200, 100x150, etc. Such beams conform to standards (after calculation), if you plan to cover the aperture is not more than four meters.
To cover 6 meters or more in length, they are no longer suitable.
Wooden beams over 6 m: fineness
Beam for the passage of 6 meters or more must not be made of beams and planks running sizes.
It is necessary to remember the rule: the strength and stiffness of the overlap to a greater extent depend on the height of the beam and to a lesser extent - on its width.
On the joists operates distributed and concentrated load. Therefore, wooden beams for large spans are designed not to "butt", but with a margin of strength and allowable deflection. This ensures proper and safe operation of the overlap.
For load calculation, which will sustain the overlap, one must possess the appropriate knowledge. In order not to go into the strength of materials of the formula (and in the construction of the garage is exactly redundant), normal the developer is sufficient to use an online calculator for the calculation of wooden odnoprolotnyh beams.
Leo060147 (User FORUMHOUSE)
Samostroyschik more often than not is a professional designer. All he wants to know - it's what you need to mount the beam in the ceiling, so that it meets the basic requirements about strength and reliability. This allows to calculate the online calculators.
Enjoy the simple calculators. To make the calculations required values, simply enter the size of the lag and length of flight, they must block.
complete table can also be applied to simplify the task.
How to calculate the distance between the I-beams
If you carefully read from the table above, it becomes clear that an increase in the length of the flight in the first place, it is necessary to make an increase in the height of the joists, and not its width.
Leo060147 (User FORUMHOUSE)
Change the stiffness and strength of the lag can be upwards, increasing its height and making a "shelf". That is - made wooden I-beam.
Independent production of glued wooden beams
One solution for bridging spans great length - is the use in ceilings with wooden beams. Consider the span of 6 meters - which the beam can withstand a greater load.
By the form of the cross-sectional length of the beam can be:
- rectangular;
- I-;
- box.
there is no consensus among samostroyschikov, a cross-section of the best. If you do not take into account the purchased products (I-beams prefabricated), then in the first place comes ease of manufacture in the "field", without the use of expensive equipment and snap.
Just a Ded (User FORUMHOUSE)
When looking at a cross section of any metal I-beam, it is seen that from 85% to 90% of the metal mass is concentrated in the "shelves." Connected wall is not more than 10-15% metal. This is done on the basis of the calculation.
On the strength of materials: the larger section of "shelves" and the farther they are separated from each other in height, the greater the load stand I-beams. For optimal samostroyschika izgotovleniyadvutavra technology - a simple box-like structure, where the upper and lower "shelves" made of planks laid flat. (50h150mm and side walls are made of plywood 8-12 mm and a height of 350 to 400 mm (as determined by calculation), etc.).
Plywood to the shelves nailed or fastened with screws (not black, they do not work on a cut) and be sure to put on the glue.
If you set a double-T on a six-meter span with a pitch of 60 cm, it will withstand a greater load. In addition, I-beam to the ceiling of 6 meters can be laid insulation.
Also, using this principle, it is possible to connect the two long boards, putting them in a "package", and then put them to each other on the edge (in the board take 150h50 or 200x50), as a result of the beam cross section or be 300h100 400h100 mm. Boards put on glue and pins are tightened or planted on the capercaillie / dowels. To the side surfaces of a beam can also be screwed or nailed plywood after coating it with glue.
Also interesting experience forumchanin nick Taras174, who decided to make their own glulam I-beam to cover the span of 8 meters.
For this forumchanin acquired SIR sheet 12 mm thick, cut them along the length into five equal parts. Then I bought 150h50 mm board length of 8 meters. Cutter "dovetail" chosen in the middle of the board groove depth of 12 mm and a width of 14 mm - so as to obtain a trapezoid with downward expansion. OSB slots Taras174 pasted with polyester resins (epoxy), previously "shoot" to the end strip stapler glass plate 5 mm in width. This, according to forumchanin, would strengthen the structure. To speed up the drying of the glued portion of heated heater.
Taras174 (User FORUMHOUSE)
On the first beam I trained "hand stuffed". The second made 1 day in advance. At cost, including all materials, including whole board is 8 meters, the cost of the beam is 2000 rubles. 1 pcs.
Despite the positive experience, such a "squatter" is not spared a few critical comments made by our experts. Namely:
- MUST NOT be used in laminated structures and freshly sawn unseasoned board since it is impossible to predict how behaves this beam in the long run.
- Milling installation groove for SIR. Prefabricated beams are milled so that the groove is obtained narrowed down - the so-called wedge. Sheet SIR glued in "shelf" in tension. This increases the density of the abutment plate and wood.
- Low technological work, which leads both to an increase in manufacturing time of one beam, and its ultimate cost.
- Can not be used as an adhesive epoxy resin. Epoxy resins have poor adhesion to wood. Also, it takes a long time until they harden. Supporting structures are glued on melamine, resorcinol, or polyurethane. These adhesives are not only not burn, but are thermosetting. I.e., the higher the temperature, the stronger becomes compound.
You can not be glued beams on PVA glue, so it is not intended for use in such constructions.
For the manufacture of the beam does not need to use fiberglass, heat the glue seam. It's simple: frezeruem slot to put the melamine glue, insert into the slot CAP, hold clamp and hammered a nail at a 45 degree angle. Back down to 20 cm and repeat the operation. Nail performs temporary lock function. All about everything out for 2 hours. A beam can already be installed in six hours.
Despite the deviation from the conventional technology, I-beam, made forumchanin, has been challenged in the adhesive joint durability and withstood it.
That's the test, which were subjected to the wooden floor beams of 7 meters:
Taras174 (FORUMHOUSE User)
I fixed the ends of the beam on two supports at seven meter distance and loaded its cargo of a total weight of more than half a ton. They could hear the first crackling seam, but then the sound stopped. Beam (from the horizontal) bent only 20-24 mm.
In the real world, one beam is not subjected to a concentrated load in one place, so a separate I-beam fabrication experience can be considered successful. According to forumchanin, is the best option to cover the distance of more than 6 meters and make free layout of the house. Especially because, despite the "metal strength" of this design, pick up and mount it possible for one person.
On FORUMHOUSE you can find out when and how you can make metal joists for span of 4 meters and 6 meters, and in particular than the steel structure, how close the span of 5 meters beam. The forum also collected All information on independent manufacturing laminated I-beams. Gameday discuss why can sagging beams. Our article tells how to build karkasniki in the United States. Watch the video a frame house, barn.