Roofing hardboard on old hardboard under the tiles

[Den oroliga byggaren]

Hello all builders,
The roofer suggested we should leave the old oil masonite in place and nail the new one over the old - isn't that cheating?
I understand that it's simple from a weather perspective as the concern for rain decreases.

What do you think?

 

[jonaserik]

Let it remain, oljemasonit is only on newer houses because it's cheaper than råspont and becomes like a hammock between the rafters. Even a membrane is sometimes used. Very good thinking by the carpenters as its removal risks soaking the insulation in the attic. No cheating with that.

 

[Den oroliga byggaren]

Leave it as it is, oil-tempered hardboard is only on newer houses because it is cheaper than raw planks and becomes like a hammock between the rafters. Sometimes a membrane is even used. Very good thinking by the carpenters as removing it risks soaking the insulation in the attic. It's not a shortcut.

Okay, just feels annoying because some boards are ugly on the underside and you will always see it from the attic, and during an inspection, it will be noted. How it looks between the boards you won't see either.

 

[Jonatan79]

It's just a matter of paying to remove the old ones, that's up to you.

 

[Den oroliga byggaren]

Just pay to remove the old ones, that's up to you.

The builder wants to keep it because the risk of rain and subsequent moisture damage is reduced.

 

[Oldboy]

I would probably like to have a small air gap between the layers of oljeboard. 12 mm or so should suffice. Just enough to allow some ventilation. I think it might mold otherwise since oljemasonit becomes thoroughly damp.

 

[Den oroliga byggaren]

I would probably prefer to have a small air gap between the layers with oilboard. 12 mm or so should suffice. Just enough to allow for a bit of ventilation. I think it could mold there otherwise since oil masonite gets thoroughly dampened.

The roof replacement was canceled because summer is what it is and we want to get rid of the old masonite since the Anticimex inspections included in our insurance will definitely complain about the double layer of masonite, which is also partially damaged in some areas - it becomes a real patchwork.