New Roof concerns

[Flat-Bumps]

Hello,

Recently I had a complete reroof. No membrane natural slates roof replaced with non-permeable membrane and manmade slates.

After the roof was complete I went into the loft and I expected to see the membrane covering all the internal roof space.
The pics show something sticking below the membrane. This doesn't make sense to me. So hoping someone here can tell me what this about.

Thanks.

 

[Wayners]

Looks like the wood is to nail last few rows down... Maybe.
I think that gap is a mistake.
Maybe.

Watch this video as shows some information that will help you.