Pitched roof sarking membrane

miltong · 10-24-2005, 06:20 AM

Hi all,

I am removing plasterboard from a coverted loftspace to install rigid insulation. However, when bashing the plasterboard off, my hammer went through the roofing felt that lies underneath the tiles, and has created a small hole.

Is this a major problem (i.e. would I have to replace the felt), or can this be patched from the loft-side of the roof? Or can it be left alone hoping that the tiles will do their job? If so, how would I patch it?

Thank you.

AaronB · 10-24-2005, 08:10 AM

Did you penetrate the primary covering?

miltong · 10-24-2005, 02:27 PM

Thanks for replying...

Um, not really sure. I am based in the UK so we probably do things a little different.

Usually (in older houses), we have rafters onto which a waterproof felt is nailed. On top of this are nailed tile battens to suppot the tiles. I have punctured the waterproof felt. So my question is, if the tiles do their job properly, there should be no water flowing through the tiles and onto the felt. In essence, the felt can be seen as a secondary barrier. In other parts of my house (constructed 1934), the battens are nailed direct onto the rafters and the tiles mortared directly onto the battens (i.e. you can see the underside of the tiles from the loft space). This does not leak! I hope I have described the situation a little clearer.

AaronB · 10-26-2005, 09:35 PM

If it is done right, from what I understand of tile roofing, it should not leak, but if it done like here in the states, the tile is only used as a UV barrier, many times, with a hot mopped roof underneeath. This is about all I know about tile roofing. I am sorry if I am of no help.