Replace or refix roof underfelt

[gavin9537]

I have a 1930s semi with an unconverted loft that I use for storage. The floor is insulated and boarded and the inside of the roof is covered with some sort of heavy duty, black fabric material - is this underfelt? (see pics). The fabric is held in place with felt nails into the rafters. In recent years, the material has started coming loose and tear under it's own weight as it comes down. I am minded to either replace it or to try and better fix it to the rafters.

Is there now a better product that I can use to replace the bits that have come down, or should I persist in re-fixing this material back up?
If I re-fix it, is there an alternative to felt nails that is more likely to hold it up?

Thanks

Gavin

 

[Alastairreid]

That's type 1f tar felt. Probably been fitted to stop dust and debris coming into the loft.
You can use breather membrane stapled to the rafters starting from the ridge and work down.

 

[gavin9537]

Thanks Alastair

Any recommendations for breather membrane? Would Tyvek be suitable?

 

[Alastairreid]

Tyvek will be fine.

 

[datarebal]

Klober permo forte .. tons better