Lime mortar torching & ventilation advice

[emmarob72]

We have a 1930s house with a tile roof without any felt. It has lime mortar torching which falls constantly. We only use the loft for storage but I'd like to stop everything getting covered in the mortar. I have a few questions as I've had some existing advice from roofers:

Is it ok to have the tile roof with very poor quality lime mortar- there's huge areas now where there isn't any left?

I'd like to put something up against the rafters to catch the torching so it doesn't ruin everything were storing up there and cause such a mess when we open the loft hatch. Is it ok to use a breathable roofing felt or would some sort of breathable fabric be better? I'm very conscious that I don't want to cause problems with ventilation or fail to spot any leaks. Someone suggested I could just plasterboard it but would this cause problems with ventilation/missed leaks?

I'd like to increase the loft insulation but have heard problems about "cold roof" causing damp either at the level of the felt or at the level of the insulation. Is it best just to leave it with the current insulation at it is which doesnt seem to cause problems at the moment?

Thanks!

 

[Lower]

You can staple a breathable membrane to the underside of the rafters to funnel the torching that drops out to the edges of the roof and away from whatever is directly underneath.

However, expect it to still be very dirty and dusty up there. Old roofs like that allow massive draughts to blow through them so dust from other areas will still carry under the area you cover with membrane. But it will reduce the problem.

I wouldn't worry about the lack of torching. It was there to stop wind driven snow getting under the tiles and help stop the tiles lifting in strong winds. However, if its falling away (and its the same with my roof) its not really doing much. Depending on the size of the roof, its probably going to be more cost effective to completely reroof that clear out the old torching and redo. Plus new roof would be felted and would be much cleaner and less draughty.

There shouldn't be a problem with increasing the insulation level as long as you don't push it right up to the tiles in the eaves.

 

[Phil 638476]

I understand this is an old thread but I have just replaced the lime torching in our loft, although time consuming it is a very easy and relatively cheap job. I used a total of 25 bags of premixed hemp lime plaster and it cost less than £300. A hell of a lot cheaper than replacing the roof.