Roofing felt advice for loft

Nikkei

Hi all,

Our house was built in the 1940s and the slate roof has no sort of felt or anything on it. We are converting the loft ourselves and have noticed that you can see the sky at night through some gaps in the slate, a friend told me that we should put felt up on the inside inbetween the wood, any advice? what sort of felt should i use, where to get it from. Might sound stupid but I guess there is a difference between the felt you would use for this and the felt you use for a garden shed???
tahnk you

daveyjp

Converting the loft to what? What did the building control department say about insulation?

27col

The felt that is used for roofs is called slater's felt. It has some sort of woven thread in it. This is to prevent tearing. The felt used on a shed is supported by the roof boards, but will tear easily if unsupported. There are new materials available now which some roofer will no doubt be able to tell you about. You can buy slater's felt at any builders merchant.
I am not sure what you hope to achieve by by applying it to the inside of the roof. Its main purpose is to prevent leaks in the event of a failure of the slates/tiles. It also plays a big part in keeping wind blown dirt and dust out of the roof space. It really needs to go on the outside of the roof under the slates, to do its job properly. I suppose that if you put long strips between the joists then it would do much the same job, but it would be a fairly unorthodox way of doing it. Hopefully, someone in the trade will have some thoughts on the matter.