A Suggestion for Those Living in Damp Climates

[cleverdick]

For anyone living in a damp climate (such as England), who might also be thinking of building their WFO in a roofed enclosure, I would say this:

Make sure you can easily remove or displace at least one or two of the roof tiles. (The ridge and verge tiles have to be fixed, obviously.) It won't be possible with flat slates, where every one has to be fixed. But interlocking concrete or clay tiles, which hang on the battens, are suitable.

This is necessary for periodic curing, in order to allow steam to escape.

I started a mini-cure on my WFO yesterday, after a prolonged period of torrential rain and non-use. I pulled out some of the rockwool lagging just to help it breathe. (The actual dome is covered with ceramic blanket fixed on with adhesive.) You would not believe the steam and condensation! Obviously the drying process cannot take place if steam can't get out, which worst-case, could condense on the underside of the roof tiles, run down and ultimately end up under your cooking floor!

Just a thought...

[silvfox]

Re: A Suggestion for Those Living in Damp Climates

Good point. Moisture on the roof sheating in any temperate climate with freeze thaw cycles can be expected. I would think that a vented soffit and ridge would always be prudent and certainly planning to include it in my build. It does'nt require very many inches of free area with the few square feet of surface. John

[Laku]

Re: A Suggestion for Those Living in Damp Climates

Technically speaking there should always be non water permeable underlay under the slating/roof tile if you wan't the structure to remain dry beneath it.

[deejayoh]

Re: A Suggestion for Those Living in Damp Climates

If your roof is sound, you shouldn't have any moisture that requires curing of your oven after the initial cure. Your problem might be more likely due to condensation caused inadequate venting of the enclosure. A sealed space that is warmer than the surrounding air results in condensation forming in the enclosure. I'm in Seattle, and I haven't had any moisture problems. My enclosure is vented at both eaves and at the peak

[cleverdick]

Re: A Suggestion for Those Living in Damp Climates

Thanks for replies so far.

I agree that a membrane under the tiles would slow down the penetration of moisture, but I don't think it would stop it totally. Here, bituminous sheeting (like tar paper with a fibre mesh) is common, and more recently, synthetic breathable types. Older houses didn't have any! But if the air is damp then surely some moisture penetration is inevitable - with or without. I don't believe there's much you can do to prevent this. Maybe some large bags of silica gel?

Also, to me, the idea of being able to temporarily remove some of the rockwool insulation (if you have this) seems worthwhile. I would be uneasy with a permanently sealed oven.

A vented ridge of course will let steam out, but also let damp air in. As will the chimney.

I guess the only real solution is to never let the oven get damp - and that means using it regularly!