Damaged felt under roof tiles

Roofs didn’t have felt or breathable membrane 100+ years ago and we’re fine the house I’m working on today doesn’t have any original Victorian slate roof easily 100 years old timbers are fine she had a leak caused by split chimney flashings, the felt/breathable membrane is a temporary covering to protect from the elements whiles the actual roof goes on you should never rely on it to keep the elements out. If you have a leak you wanna address it at the source of the problem repairing old felt is just hiding the issues and long term would rot timber battening hold and supporting tiles/slates and cause rot at the bottom of the rafter ends(eaves) I wouldn’t stress about it, anybody telling you otherwise doesn’t understand how a roof actually works and is trying to create work for themselves, you only employ a roofer as and when your roof is leaking and they should always repair the leak at the source eg broken tiles, split lead flashing etc not just patch work repair holes in felt to hide the issue. Regards Frankie BT Roofing Services

Yes it can allow water ingress into the structural timbers of your roof creating rot.& dampness there has always been felt in roofs but not always as we know it the lathes used to be pointed up with lime mortar which caught any drips, then there was slaters felt now its breathable membrane, have had this discussion on many jobs with the building inspector about adjoining roofs where the felt is degraded and the house holder has been told by there so called expert roofer that its not required and the result is always the same response from building control a see the neighbour has had the cowboys in. without properly fitted under felt you will have dampness and rot in your house this is why so many expert roofers dont want building control any where near there job and will find lots of different reasons not to have there i.e saving you money ect, building control are required if any more than 25% of your roof is removed and have been since 1st of October 2010 without the correct paper work your new roof will not be reconsidered and may invalidate your insurance policy

Hi there the felt is a second barrier it does protect any timber rafters but what keeps the water out is the tiles / slates so any leak will be from damage to the outside covering but I would still recommend any large areas with torn /hanging felt should be replaced if there is a problem

I would say a overhaul inspection of your roof would be a good idea... yes your underlay membrane should not be hanging lose anywhere under your tiles/slates . It’s your first layer of protection an if it is perishing an hanging down potentially something isn’t right somewhere .