Purlin Clear Span

[dkb]

Hello
Following on from my last question about a split purlin I did some digging on regulations.

The length of the purlin is 4m. The size of the purlin is 270mm x 70mm.

Looking at the tables this isn’t sufficient? In fact nothing seems to allow a clear span of 4m. House is mid terrace built in late 1800s. I expect the whole street is like this though.

Am I reading this incorrectly?

 

[noseall]

It would not comply with todays' standards, no. But neither would a million other homes.

 

[dkb]

That's what I thought. The rest of the street is like this as I suspected.

 

[^woody^]

But .... is that the reason it spilt in the first place?