Wooden floors. Wooden beams for ceilings for a large span How to block a span of 6 meters

01.10.2010, 11:47

calculation:
1) beam 200 * 200 * 6000 through 0.5M = 22 tr (deflection 20 mm)
2) I-beam 20B c / o 1.2m = 27 tr. (deflection 20 mm)

By weight 1) -90 kg timber, 2) - 120 kg beam

In theory, the solutions are very similar. Interested in practice, which is better?

Green Cat

01.10.2010, 11:55

Bar.
In general, you should not make any load-bearing structures with iron, because in case of fire, the tree holds on to the last, and the iron is cracked and ready.

01.10.2010, 15:55

The temperature at which the deformation of the I-beam will go is incompatible with life. Especially if from below it will all be sheathed with drywall.

If you still decide to make wood, then I advise 200x60x6000 in increments of 600 mm.

01.10.2010, 16:55

"hryas and ready" - but it won't matter anyway)))

It can deform in one place and fly to another, where there are still conditions for life ... :) but in general you are right.
+Wood itself will sustain combustion, but iron will not...

Green Cat

01.10.2010, 17:41

The temperature at which the deformation of the I-beam will go is incompatible with life.
Not right.
It's one thing when it's on its own, and another thing when it's under load.

Until recently, it was generally forbidden to use meth as rafters. profile, now I'm doing it with might and main.

I advise 200x60x6000 with a step of 600 mm
It will be too small, too small - we look at the caculator.

01.10.2010, 20:32

In my room, the span turned out to be 5.7 meters, the overlap between the 1st and 2nd floors. I chose an I-beam 20B after 1.3 meters, it seems that according to the calculation, the I-beam was stronger than wood. It is worth considering that a tree can be found 6.5 meters long, and the length of an I-beam is 11.7 meters or 12 meters (to cover a span of 6 meters, you need at least 15 cm per side). It would have been better to lay the plates, but I did not succeed. The difference between a tree and an I-beam was somewhere around 10-12%. When laying the walls, I installed 3 cm foam plastic between the cutout in the gas block and the I-beam.
As for the fire, you need to protect yourself.

02.10.2010, 00:47

And I put a 5.8 meter reinforced concrete slab on a 6 m span and don’t think about anything else. Doesn't burn, doesn't melt, doesn't bend...

02.10.2010, 09:00

Thanks to everyone, I still lean towards an I-beam, since it is stronger, I want to put internal walls of 100 cm foam block on the ceiling. (although it was probably possible to put 2 beams under the wall)
then wawan001 span 6M is along the axes of the walls, that is, there will be 15 cm on each side of the support.
then the Cat, I suppose if you fill up a non-combustible insulation ala expanded clay, then there will be nothing to burn there at all (a foam block house).

And another question, if you overlap with an I-beam, is it possible to use a wooden, say, 50-ku fixed to the side walls instead of the extreme beams ??

02.10.2010, 18:30

There is another option.

02.10.2010, 19:12

There is another option.
You make a carrier beam (albeit from an I-beam), on which you lay simple wooden floor beams. It will come out much cheaper.
I-beams will need one or two, but powerful. The price will still come out cheaper.

I did it myself

02.10.2010, 20:01

dengt, this idea came to my mind from the point of view of the manufacturability of the device in the future of the floors, if the wooden floors are installed inside the I-beam, and on top to make a counter-lattice (beams according to the calculation). The distance from the edge of the beam to the I-beam is 40 cm - reliably. Indeed, according to calculations on the extreme beams, the load is less than 2 times than on the neighboring one, you can put a 150x200 beam or take 2 pieces of a 50x200 board and install pieces of a board of the same size 1.5 meters long between them, and I think 50 is flimsy, although if the wall can pull and it will be fine. If you are sure about the fasteners, then probably yes.

04.10.2010, 05:57

I blocked the span with a 5 m beam 150 * 150 folded in half and tied with studs, i.e. it turned out a beam 150 * 300. It turned out pretty tough, but I would still make it out of concrete if I had the opportunity :(

05.10.2010, 09:32

[
i did it myself
span 11 by 6, divided into three parts by two I-beams and laid wooden beams, and in order not to increase the thickness of the ceiling, he laid them inside the brand. I pre-welded the corners to the brand and fastened the beams to the bolts.

As I understand it, I-beams were 6 meters long?
here already a minimum of 25B2 is needed, this is a 5 cm thicker overlay, it seems not fatal.

As for fixing the side beams to the walls, I am worried that all the other beams will sag and the outer ones will not, then the slab will sag with a “bubble”? what will it come to?

05.10.2010, 10:11

I-beam 6-gauge 20B1 - two pieces across the length, it turned out 3 zones, two with the support of beams of one side on the wall, and the second on an I-beam, and one zone with beams sandwiched between the I-beams. I did not notice any deflection, an I-beam does not go at such a length.

06.10.2010, 13:06

06.10.2010, 13:47

depending on how to load, if according to the theory 400 kg / m, then in your case 20B1 will bend by 77 mm

I wonder how you calculated it?

The span table of the frame house floors helps to choose the correct section of the floor lag, which means avoiding problems with floor sagging, creaking and vibration when walking. Our homegrown approach - to take more beams - is not economically justified. The board is cheaper than a bar, especially a large section. Most often, the length of the spans of the floors is in the range of 3.5-4.5 meters and, observing the correct section and step, you can install a reliable floor.

Let me remind you that the floor joists are set with a certain step, a multiple of the long side of the rough sheathing slab, namely 305 mm, 407 mm, 488 mm and 610 mm for osb / plywood board 2240 x 1220 mm in size.

For 305mm pitch (12" OC)

For 407mm pitch (16" OC)

For 488mm pitch (19.2" OC)

For 610 mm pitch (24" OC)

Where did the data in these tables come from?

How to work with tables correctly and what are residential and non-residential loads?

Residential is everything that is located and moves around the floor space: people, objects. Non-residential load is the weight of building elements. For example, the weight of the floor lag and subfloor slabs.

Depends on what will be located on top: a double bed or a regular chair. The final floor covering can be a light laminate, or it can be a warm floor screed with tiles.

Typically, for residential premises, the total load is in the range of 200-250 kg per sq.m. If you plan to install a cast iron bath, then look at its weight and add a lot of water and yourself to it.

What type of wood are these values ​​taken for?

Since our markets do not have a quality system and an accurate determination of the grade of sawn timber, the tables show the values ​​\u200b\u200bfor ordinary spruce and grade II pine according to the North American classification.

The actual dimensions of the section of the boards in the American tables are smaller than the European ones, what should I do?

It's true. If Americans say a board is 2" x 6", it's not 50.8mm x 152.4mm. In fact, it is 38.1 mm x 139.7 mm. The reduction in the cross section of the board occurs as a result of drying and planing. Our sawmills, lumberyards and markets also do not have a furniture store. Sellers claim that the board is 50 mm x 150 mm, but in fact it can be 40-50 mm x 135-150 mm.