Beefy ridge beam check and plan to reduce size

[saveasteading]

2 hours ago, NandM said:

choice of UC over UB.

Ond reaso perhaps is: As you have a portion with roof loading to only one side, this puts a twisting load into the ridge which a UC will resist better than a UB.

[saveasteading]

4 minutes ago, cwr said:

torsional buckling. 

I was writing the same as this was posted. The roof is only on one side to part of the length. A UC will resist this. A UB might need stiffening.

[Gus Potter]

On 20/03/2024 at 08:06, Conor said:

Structural elements need to be protected from fire if they are supporting a habitable area or an escape route. A roof ridge beam does neither of these, so does not need protecting whether timber or steel. I think some over zealous BCOs insist on this applying to roof structures.

Conner is pretty much right, many roof structures don't need much if any fire protection.. but there are some cases where this rule is not applicable.

 

If you look at the building regs you'll see a bit that says roughly that if an element of structure is contributing to the stability of an element that needs longer fire protection then that bit too has to have the longer duration protection.

 

I've had this "experience" when working in and around party walls and boundary walls / walls close to boundaries that need say an hours protection. Past "unjoyfull moments" include attic conversions and adding and extra storey onto a single storey garage attached to the house..

 

I have sat down and worked out a structural solution, made myself a coffee and felt quite pleased with myself.. until is dawns.. oh no!.. I need that bit to have a longer protection.. bubble gets burst and it can be expensive (for the Client) and time consuming (for me) to sort that out.

 

To finish it's worth trying to understand, if you can, how your building stays up.. it needs to carry vertical load but also all work together to stop it falling sideways either in the wind or by just being a bit off the plumb. Quite a lot is common sense.. a lot of folk have intuition. If you think about houses you have been in that have open spaces and say high ceilings and walls.. you just get that feeling that things look a bit too slender or the upper part of the building just looks too heavy / catches too much wind to be sitting on what is below?