Universal column or universal Beam

[Gustav75]

I have an open plan kitchen & family room approx 8.4m by 3.6m. I have noticed in the middle of the room that the ceiling is slightly sagging approx 25mm, you would never notice it unless you put a straight edge to it but it is more noticeable in the bedroom above.
The ceiling joists run the 8.4m length hence I would like to install a beam across the middle of the room at 90degrees to joists. My question is which beam is more suitable, UC or UB.
I am reckoning a 152x152x30 UC or a 203x133x30 UB, I would prefer to install a column beam due to it being 50mm shorter depth and not so intrusive but is it more flexible than the universal beam?
Local engineers have a backlog and unable to assist me for months... hence the advice requested.

Any advice is certainly helpful.

 

[PropRepairAdvice]

You need a structural engineer and building regs approval. Speak to the building control department at your local authority first.

 

[Gustav75]

Thanks. I am fully aware that I require build reg and engineers report as I have installed many beams in the past, however I know that either beam mentioned will do the job. I am looking for advice as I have both beams in the yard (152x152x30 UC or a 203x133x30 UB) and I have a buyer for one of them. I do not want sell it if I will need myself in the near future. The question is which beam will have a lesser bending moment?

 

[martin hill]

Hi there

Are the joists timber and what size?

8.4m for timber is a long unsupported span. Have the kitchen/family room been knocked thru into one.

You will have to get a structural engineer which i know you are aware of but in the meantime can't you contact an engineer and ask him what is the max load for the two beams you already have.

There are companies who will do calculations online for a fee. Also if you not in a detached house you may need to get a partywall agreement too.

 

[frutbunn]

8.4m length timber??? Never seem anything like that in my life. Are you sure there isn't an intermediate support.
Strictly speaking the installation of a steel beam to reduce the deflection in an existing floor does not require a B Reg app.

 

[Gustav75]

The length is made up off 2 x 4.2m joists connected with nail plate. It does not require building reg intervention as there is no load bearing above. Its purely to reduce the deflection which is very minimal.

 

[frutbunn]

The length is made up off 2 x 4.2m joists connected with nail plate. It does not require building reg intervention as there is no load bearing above. Its purely to reduce the deflection which is very minimal.

I'm amazed it has so little deflection.

 

[Celeronmanuk]

The length is made up off 2 x 4.2m joists connected with nail plate. It does not require building reg intervention as there is no load bearing above. Its purely to reduce the deflection which is very minimal.

Goodness! What size are the timbers out of interest?

 

[martin hill]

The length is made up off 2 x 4.2m joists connected with nail plate. It does not require building reg intervention as there is no load bearing above. Its purely to reduce the deflection which is very minimal.

Regardless of no load bearing above it still has to carry the dead load of the joists/floorboards themselves and the live load of the furniture etc upstairs. You will be better off putting the beam at the nail plate join.

You can get this calculation done on line for a fee.

I have to say that a slight sagging upto now you are very lucky.