Ridge Board

Doop

Hi, I have a query about roof construction, the house is a 1950-60's two storey dormer bungalow with a good size attic above the upper floor (7-8ft floor to ridge board within the attic void). It has a dormer extension to the rear constructed a good number of years ago but date unknown.

The ridge board appears to be a piece of tongue and grove timber and appears undersized. The timber is 20mm thick and 150mm wide. Photos attached. I cant really understand it as everything in the attic structure appears orginal but this looks off. The only guess I can think is maybe when they were constructing the dormer they possibly swapped out the ridge bard and used this timber instead? Or maybe its orginal and been there 50+years.

Is it a cause for concern is really my question? The roof doesn't have signs of deflection or other issues. The first photo is an overlapping section and the second is the timber on its own.

Appreciate any advice!

10-10-20

Sounds like a non-structural ridge board as opposed to a beam. Have a look at this, but I'd guess that its fine!

https://www.techsupport.weyerhaeuser.com/hc/en-us/articles/207291947-Ridge-Beam-vs-Ridge-Board

Lumen

In theory a ridge board only takes compression force between mating rafters, but that assumes the rest of the structure is built correctly.

I don't see any collar ties (are there some out of shot?) so maybe you're relying on continuous joists to tie the roof together and prevent ridge sag. If those are broken at any point, e.g. by an attic hatch, then you might have rafters putting a bending load on the ridge board, for which it is not "designed".

This is not a professional opinion and if you're concerned get an engineer to look at it.