Using Structural Timber for Lintels on New Works

[StopHammerTime]

Hi all
Wondering if I could bounce an idea off you before submitting it to the BC officer and potentially ****ing him off early on?
Doing a loft conversion and BC officer asked us to change all 2nd floor timber window lintels to concrete and reenforce all timber door lintels.
I've done all of that except on one (big) window lintel, it's a proper pain to change and is going to hold up works . All the other walls had blockwork above them - this is one wall with a pitched roof going down it, the roof is resting on an rsj meaning this timber lintel is only carrying four or five floor joists (floor joists are a 3m span, so half of that) and 1 metre is eaves storage. The timber lintel is 9"x4", now before I argue that it's carrying barely any weight I envisaged the BC officer having an issue with it being ungraded timber (it's exposed and in good shape but never the less 100 years old), I was planning on reinforcing it with either one or two 50x175 C24 timbers the whole length and bolting them all together.

Am I underestimating Building Control's hatred of timber or (optimistic) going overboard?

 

[tony1851]

Unless you are increasing the load, there is no justification for replacing original timber lintels with concrete. As long as they are suitably fire-protected there should be no issue.

Existing timber beams - even old ones - are usually assumed to be C16 grade. That is conservative because much older timber is usually of a higher grade.

(Note: this applies to England and Wales regs, RoI regs might differ).