Too weak beam? 220 joist in 4.8m opening

[AskeHolst]

In one room of our house, a brick wall has been removed and a beam has been put in instead, 22cm high, 11cm wide. It seems weak, but it hasn't collapsed.
We are planning to have a fully tiled bathroom directly on top, should it be reinforced?

 

[Vante]

According to Svenskt trä dimensioning with heavy floor structures tiles etc.
115x495mm with a utilization rate of 69%
4800mm is it the entire span or up to the partition wall?

 

[AskeHolst]

495mm becomes very tall, so it will have to be a steel beam instead, like hea180. It might be too optimistic to think that the existing one will hold, but it doesn't feel like it's bending and it's been there since 1952, maybe the timber was better back then

 

[bossespecial]

More information is needed to be able to answer, such as how much of the bjälklag rests on the beam. Do you have any drawings of the house, plans, and cross-sections?

 

[AskeHolst]

There are no drawings unfortunately, the house is from around the turn of the century, remodeled in 1952. I made my own after we bought the house, not entirely accurate though. The blue room is the one with the crossbeam.


The floor on the upper floor as it is now:


- Crossbeam in the middle, 220x110 beam (orange)
- Original beams, 195x110 CC120 (yellow)
- Extra beams, split in the middle 110x110 (green)
- Walls on all sides are brick (blue)
The bathroom should be within the red frame.

In cross-section:

 

[bossespecial]

Awesome Is there a basement in the house, do you have a sketch of this floor as well if so?
As mentioned, “skärmväggen”, should it remain?

 

[MathiasS]

It is surprising that that beam does not have a visible deflection. I would probably replace it with a steel beam before investing a large lump of money in something on top of it. If you are reasonably handy, it's not particularly difficult to do the job (provided there are suitable supports for the beam).

 

[Lutte]

It is surprising that the beam does not have any visible deflection. I would probably replace it with a steel beam before investing a large sum of money in something on top of this. If you are handy, it's not particularly difficult to do the job (provided there are suitable supports for the beam).

I had calculated on flat steel bars about 10-15mm to be placed on the sides of the wooden beam. It feels like a simpler and cheaper alternative.

@justusandersson and @bossespecial should be able to give a thumbs up or down.

 

[AskeHolst]

No basement in that part, it's a crawl space with a bit more height in some places. There is a "wall" underneath where the wall once existed.


The small "screen wall" should probably be removed, it's just sparse and treetex.

 

[AskeHolst]

I had calculated on flat steel, around 10-15mm, which is placed on the sides of the wooden beam. It feels like a simpler and cheaper alternative.

Hmm, that sounds much easier than replacing... is it a common method?

 

[oscarss]

According to Svenskt trä dimensioning with heavy floor tiles etc.
115x495mm with usage ratio 69%
4800mm is that the entire span or up to the partition wall?

Where did you find that tool? I was looking around but only found dimensioning for continuous c/c distances.

 

[AskeHolst]

It is surprising that that beam does not have a visible deflection. I would probably replace it with a steel beam before investing a large sum of money into something on top of this. If you have average handyman skills, it's not particularly difficult to do the job (provided there are suitable supports for the beam).

There is a deflection, about 1.5 cm, but a bit hard to see precisely as the beam does not have exact measurements.

Sure, it is possible to replace it, we installed a HE-B 160 in another room (which does not have a bathroom above), so I know how, but it's simpler and cheaper if it is not necessary.