Part reroof - felt or no felt?

[Kinclad]

Hi there,

I'm having about 1/4 of my original wooden pegged clay tiled stripped and reroofed as the pegs and battening is failing causing slipped and lost tiles. The main structure is fine its just the pegs and battening.

Being original none of the roof is currently felted, should I felt this section as I have the opportunity or can that cause moisture problems?

I wont be touching any other section of the roof for some time because its in pretty good order. I believe over the years sections have been done before so not all of it is deteriorating at the same time, I think also this section I'm doing gets the worst of the weather.

Many Thanks for any advice,

Mark.

 

[Andys]

How about breathable membrane eg Tyvek roofing underlay? It's designed to transmit water vapour, though I'd still be keen on some ventilation too.

 

[middi]

Hi
You can certainly use breathable membrane under the section of roof which you will be repairing with no ill effect , however, this will be of little benefit until the rest of the roof can be also " treated" with a complete breathable membrane cover in conjunction with correctly applied insulation.
Also, if you intend adhering to originality and reinstate the clay tiles with hand made wooden pegs, you will have difficulty ( or more like impossible) to use these as they have to protrude well below the lower part of the batten to secure the tile in position long term . As the breathable membrane needs to be stretched reasonably tight to perform well below the battens the " pointed" pegs will defeat the object . You can, if you want, measure every (pointed) tile peg for tightness in the tile ( usually square !!) hole and cut off the excess so that it does not protrude below the batten. There is no point, originality is again destroyed.
In these days of energy sensitive times a happy medium has to reached between conservation and thermal efficiency and it is quite acceptable to use large head aluminium " peg" nails of appropriate length to secure original clay tiles onto battens ( easily available from builders merchants). These " nails" are used peg style without fear of the nails going through the peg hole due to their large head and will speed up tile laying time five folds. Breathable membrane and insulation will complete the job.
These are only suggestions and food for thought in order for you to reach a conclusion as to what you are most happy with and in the knowledge that the building aspect will not be compromised. If the building is listed let the conservation officer know what you intend to do.
Good luck

Middi