Pros & cons between universal beams vs parallel flange channels

[Lisa Stephens]

Good morning.

For my loft conversion the structural engineer designed PFC steels to carry the new load of the 9" X 2" C24 floor joists. The building control officer stated that I could have also used universal beams instead, because "it would have cost a lot less in steel". Is this an accurate statement to make?

My understanding is that I had to follow the structural engineers drawings verbatim and I couldn't deviate from them because he's the professional designer of the loft conversion.

When I asked both the structural engineer and the building control officer what the pros and cons are between using universal beams and PFCs, they both refused to tell me.

The Structural engineer has told me to stick to the details in his drawings and to not let the building control officer take me off course with his silly statements. However, I'm now curious and I want to understand the differences.

Could someone please tell me what the pros and cons are between using universal beams and PFCs in a loft conversion with a rear dormer?

 

[John D v2.0]

I heard PFC was good for cavity walls as you can space them as you like then bolt together. Also it's better from a H&S and labour point of view because it's basically two halves to manipulate.
However the SE should tell you because you've paid him and he should design to your requirements. I only know from our SE, and he redesigned a pair of PFC to be a UC because the architect requested it.