Hello, I am collecting quotes for my lodge, roof area about 300 sqm. Moisture has penetrated about 30 sqm where the underroof, raw lath needs replacing. Currently, I have chipboard lying on top of the raw lath, then battens and tiles. I will replace the wet, rotten parts on the roof, as well as the battens and new tiles (keeping the old single-cambered ones!). Contractors have different opinions on whether to use roofing felt and whether to remove all the chipboard from the entire roof or not. Some companies emphasize the need for felt or membrane to prevent moisture penetration, while others say that the air gap between the tiles and the raw lath is sufficient to transport away any moisture that gets under the tiles. Any advice and tips are appreciated on how to proceed and what to consider?
I would say that if you have clay tiles, you absolutely need to have underlayment. Clay tiles are not as watertight as concrete tiles. It's best to have extra good underlayment when using clay since some water will seep through here and there. But since this is a barn, standard underlayment will work fine.
The roof was redone in the late '50s if I have the whole picture. So over 60 years. If it lasts longer with papp, that's the question!