Max. span for floor joists 220 mm

[macaroni]

Hello!
I am planning to build an upper floor on our existing single-story house.
The floor joists on the upper floor will span a length of 9 meters, and on the ground floor I will be installing load-bearing walls and steel beams (18 cm H-beam), but to minimize the number of steel beams I want to know the maximum distance for the supports, i.e., the span width.

Can a normally loaded floor with 220 mm joists handle a span of 4.5 m?

Is an 18 cm high H-beam enough for support? Glue-laminated beams take up so much space in the ceiling. I don't want to notch the joists. Too much work!

The building permit drawings are available at http://hem.fyristorg.com/warnby/bostad/

I have not yet arranged for structural drawings and plan to attempt my own drawing first to see what the building committee says.

Thankful for answers and advice!
/Marcus

 

[gullegrizen]

Know a house manufacturer that uses 45x220 with cc 600 up to 4.2 m. With cc 300 up to 4.8 m.

 

[macaroni]

Thanks for the tip, but can you name the house supplier?

Sounds good with 4.2 m. What classification is the timber? K24?

/M

 

[Mikael_L]

According to the wood guide www.traguiden.se, it is not enough, not by a long shot.
http://www.traguiden.se/TGtemplates/popup1spalt.aspx?id=680&contextPage=1465

You must register (simple and free + a good site = recommended).

But I have questioned the table in this thread.
http://www.byggahus.se/forum/byggma...gar-och-vad-gar-inte-att-bygga-loesvirke.html
Where I also sent the table as an image.
You can read the responses there, where some different opinions are expressed.

 

[macaroni]

According to your thread, it seems like you can have a 9-meter house if you splice the floor joists? Apparently, as I understand Träguiden, a floor joist should not be longer than 7 meters.

In that case, I'm thinking I would lay a 5-meter length from one direction and one from the other and then nail them together parallel. The c/c distance will still be 60 cm, but on one half of the house, it shifts slightly to the side. Should work, right? Made a little sketch of what I mean.

 

[gullegrizen]

Thanks for the tip, but can you say the house supplier?

Sounds good with 4.2 m. What classification is the timber? K24?

/M

The house supplier doesn't matter, but it's one of the biggest.
The timber is K24.

 

[Johan Gunverth]

By screwing and gluing floor chipboard directly to the joists, you can increase the span. We have 5.3m/cc600/220mm K24 at one place in the house. This has been calculated and approved by the engineer.

 

[macaroni]

I have also heard about screwed and glued. But what do you have on that floor? No heavy sections like wardrobes, pianos or similar, I assume?

/M

 

[Johan Gunverth]

I have also heard about the screwed and glued method. But what do you have on that floor? No heavy parts like wardrobes, pianos, and similar, I assume?

/M

No, nothing particularly heavy, but that question never came up. I assume it accounts for a standard load. We wanted to avoid c/c400 at all costs. That's why this solution came up.

You should still check with a structural engineer or building engineer. Alternatively, use Kerto-beams.

http://www.byggahus.se/forum/byggmaterial-byggteknik/42118-vad-aer-en-kerto-balk.html

 

[GustavW]

I have 4.5m cc300, 400, and 600 depending on the placement. Sure, there is a little flex with cc600 but not so much that it bothers...