Water is the Enemy | This Old House

Bulk water is a home’s worst enemy, then air. Siding isn’t good at stopping either. But WRBs are good at stopping water—and sometimes air too. General contractor, Zack Dettmore demonstrates water resistant barriers for Kevin O’Connor.

About This Old House TV: This Old House is America’s first and most trusted home improvement show. Each season, we renovate two different historic homes—one step at a time—featuring quality craftsmanship and the latest in modern technology. We demystify home improvement and provide ideas and information so, whether you are doing it yourself or hiring out contractors, you’ll know the right way to do things or the questions to ask. Our experts including general contractor Tom Silva, plumbing and heating expert Richard Trethewey, landscape contractor Jenn Nawada, master carpenter Norm Abram, and host Kevin O’Connor give you the tools you need to protect and preserve your greatest investment—your home.

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Water is the Enemy | This Old House

[rexmundi]

Water is less of a problem than not drying out. I’ve got a barn with poplar board siding that’s 100 years old that’s still perfectly solid. Trap moisture in a humid house and let it sink into the walls and all that OSB will be moldy dust in a few years.

[Oldhogleg]

Water barriers that can't breathe water vapor on the cold side of insulation is what's been causing the ongoing epidemic mold problems with new construction and remodels by trapping the warm humid air from the inside of the house on the cold side of insulation.

The way to wrap a house to prevent the risk of mold from condensation is to use a breathable water barrier on the cold side of the insulation and a vapor barrier on the warm side of the insulation.

[warrenphilips]

3:11 filling sample three, notice the bottom of the wood, a straight line
3:35 there is a drip forming under sample three, possibly failure around the nail

[dartleg]

how is that a fair test? the last two are sealed around the base of the tube.

[mothanwrdz]

What about vapor permeability? Does the sheathing allow water vapor to pass through?

[KJSvitko]

All new buildings should be designed with large roof overhangs. The large overhang provides beauty and protection from the sun, rain and wind.
Protection of the doors, windows and siding make for a more durable and comfortable home.

[GBDGhotbear]

Guys. This test is flawed. You have X amount of pressure forcing the water down. This will make just about anything fail on a flat surface . This is not really a good test to compare products that should be on a vertical surface. I'm currently working on a 200 year old home that has felt paper on it and all of the wood under it is fine. It hasn't saw light in about 100 years.

[danslickers]

Might want to look again. There’s a drip on the underside of the zip sheathing. It followed the path of the nail. You know it does. It’s a hard coating which in turn can not be self sealing.
Grace and Peace
Slick

[RealMTBAddict]

Sealing up concrete cracks with Sika, great stuff.

[feliiiik]

any solution for the inside if you dont want to rip out all your exterior siding just to put a new water/ vapor barrier? from my research, it seems like the answer is nothing aside from heater or dehumidifiers.

[iandunn]

That's not really a realistic test, since they're laying flat instead of horizontal. It demonstrates that Zip and WRBs are better, but it doesn't prove that house wrap is insufficient.

[RossMalagarie]

House wrap is not waterproof it is meant to deflect water because the water should be running off the wrap and not sitting on it on the side of the house.

[tacojohnhg]

Some of you need to get your eyes checked. They put silicone on all 4 of them. The last 2 have more, but it's there on all of them. The "test" is to show how it permeates through the membrane. It's sealed on all of them, just whoever did it, was sloppier on the last 2.

[MorseB]

The issue is airflow is good. You need airflow to dry things out. Water is already inside the house, showers, dishwashers, small leaks. That moisture needs somewhere to go. There is a reason that mold isn't generally a problem in old houses and only started to be a massive problem in the 90's when houses became too airtight.

The question should be, why could people afford to heat uninsulated houses in the 70's and before, but can't now? Why isn't it on the billionaire owned power company to lower the price of energy, rather than the paycheck to paycheck home owner to go to extreme mold promoting lengths to keep a house so airtight simply to afford heat?

[virgil]

So the first 2 have been around for what seems forever, and obviously not good. So why are they still allowed to be sold and used?

[johnlebzelter]

And here come all the “pros” comments.

[debluetailfly]

With all the new 'miracle' products on the market, how is it that well built old houses can last hundreds of years and new ones fall apart within a few decades?

[garyblodgett]

Well, as a former 35 year large loss adjuster, occasionally when I was at a plumbing water loss, a customer (insured) might ask what caused this?

My favorite reply was, “Well, this all started when we brought the well and the privy into the house.”

Some people got it.

[bradmitchell]

Did I see caulking on the last 2 but not the first 2 ??

[joekuertz]

The last two tubes had silicone caulk sealing at the