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I'm building a tiny house and it will have metal siding. My dad has worked a lot of construction and says he's never installed a house wrap for a metal building in his life. Most info I can find online says if it's climate controlled it needs wrapped. Just wondering how important it is when it comes to metal siding?

Also, I may cut it close when I get to the tops of the walls, I'm planning to use the rest of the #15 asphalt felt I used on the roof to finish the job if I run out so I don't have to buy another roll. Is this a good idea?

isherwood
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Mark
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4 Answers4

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While I don't doubt that your father 'never installed a house wrap for a metal building in his life' I have to wonder how many of them were residences? Buildings with walls that trap moisture or where higher efficiency insulation is often needed? Bare and exposed insulation on the inside doesn't count.

Wrap is about what is INSIDE the wrap, not what is OUTSIDE the wrap. Tyvek lets moisture out while not letting air in or moisture in. Tar paper was the old school solution but it blocks air and moisture in both directions. Tyvek or other similar modern building is needed for insulated walls with poor circulation, metal or no metal.

TylerH
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Ack
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I don’t see a problem with felt for a portion as it was used for years, I believe a wrap is a good idea as it will increase the energy efficiency and keep the condensation from the metal off the sheathing. If you use insulation under the metal as used in many roofs you probably would not need a wrap but it would still be a good idea.

Ed Beal
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I don't see what the issue would be with the Tyvek (or any other) house wrap. When my renovations were done, much of the brick was removed & replaced with OSB+Foam Board+ House Wrap + Hardiplank (cement board). I don't see why the metal siding would any different from the cement board in so far as using a house wrap.

SteveSh
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Also in this case, a reliable way to get all necessary information concerning possible moisture, insulation and mold problems is to input each material in the layer fields on the professional Ubakus website, which is free for private use. Each layer can be switched on/off with a single mouse click to immediately see the difference.

Another important aspect is a good grounding of all metal parts in order to avoid dangerous voltages resulting from the electric installations or static charges. The mobile telephone/ router/ smart home signals may be affected, depending on the windows.

xeeka
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