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by • December 24, 2014 • Exteriors - Siding, Stucco, Brick, Stone, Wood, Metal, Housewrap & Waterproofing, ReviewsComments (18)24644

Zip Wall Tips & Advice

Wood is the predominate building material in the US and what’s the #1 enemy of a wood structure? Water! The details of your Waterproofing are SO important because one small slip in the waterproofing layer and you’ve got a problem.

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So, with that in mind I’ve been reluctant to rely on solely tape products to waterproof my houses. In fact, I’ve poo-poo’d Zip Wall from Huber for a while. However, this past year I had the opportunity to build a SIPS & Timberframe house designed by Architects Aamodt & Plumb and built in conjunction with famous Timberframe company Bensonwood Homes in New Hampshire.  (Side note, I first heard of Bensonwood while watching This Old House in High School.  It’s a dream come true to build a house with their Timber/SIPS package)

Bensonwood has been using Zip in their SIPs (Structural Insulated Panels) process for a few years now and has really liked them for several reasons.

WHY ZIP SYSTEM:
#1 Easy install. Huber Zip is pretty darn easy to install for your carpentry crew. Their tape they sell for the seams is really Top Notch too. I’m very impressed with this tape after my first project.  It’s an easy system to learn because they aren’t as concerned about the Shingle effect & where to layer things.  Simply butt panels and Tape them.
#2 Air Tightness. I believe that air tightness is really the missing link in terms of efficiency for many builders across the country. This house we did with Zip Wall blew a very good Blower Door test. (stay tuned to find the results)
#3 Cost. The Zip materials themselves are a premium cost compared to some other “housewraps” but the big savings on Zip happens with Labor. The Zip Wall house requires one trip around the house compared to two with more traditional systems.
#4. Early Waterproofing. This is a big one for me. Especially with the roof panels. Usually after my framers lay the roof plywood or OSB I’m waiting a few days for the roofer to “paper” the roof for a temporary waterproofing till they come back to install the roof. With Zip you have them deck the roof and tape it same day! Drying the house early in framing is really nice and frankly pretty important if you’re building a house in under 6-9 months.

Using Zip:  After using Zip on this first house I’ve become very comfortable with their system overall.  But, I think there are some small modifications that need to be made to ensure maximum durability of your house for the next few hundred years.  Let’s look at this Bensonwood project to see how we modified Zip to suit my desire for ultimate durability.

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Bensonwood Timberframe house with SIPs using Zip Wall. Crane flying in a roof panel here.

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“Standard” Zip wall install. But, I see some room for improvement here…

Advice/Tip #1 ROOF UNDERLAYMENT IS KEY:

Early dry-in with Zip Tape is great, but I’m a big believer in putting a full Ice/Water shield product on your roof as underlayment especially if you have an un-vented roof assembly.  This SIPs framed roof has 12″ I joists filled with cellulose insulation and I need to ensure they stay dry for the life of this house.  I typically use Carlisle’s WIP 300HT for my roof underlayment.  This 40 mil product is rated for high temps and has some self-gasketing abilities.

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Ice/Water Shield underlayment overlaps the wall Zip panels by about 3-4″.

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Architects designed a very cool “over-roof” with 2x’s to create overhangs on this house. Roof has continuous ventilation under the metal from eave to ridge.

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This wall gets traditional stucco over Zip. Let’s see what we did to make it more durable.

 

Advice/Tip #2 BASE WALL FLASHING:

In almost every house I remodel I find rot at the base of the outside wall sheathing.  I believe you MUST use a base wall flashing to protect the raw edge of whatever sheathing product you use.  I’ve used Carlisle’s CCW 705 for a few years now.  Here’s a blog post for more info about how to use CCW 705.   You’ll see in the later photos that we used Zip tape on top of the Carlisle 705 to ensure it would stick properly to the Zip Wall.  That gave us about 16″ of extra protection at the bottom of this slab-on-grade house.

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This blue base wall flashing will add TONS of durability to your Zip house.

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Advice/Tip #3 RAINSCREEN ALL YOUR CLADDINGS:

Rainscreen is basically adding an air gap behind your cladding (siding/stucco/brick/etc).  In my opinion this air gap makes a HUGE impact to the durability of your house.  Any water that gets behind your cladding has air gap layer to drain & dry.  Simple, yet it’s done so little in this country.  If you build with Zip and add an Air Gap (rainscreen) I expect your house to be in great shape 100+ years from now.  This house has a mixture of stucco and wood siding so here’s how we got a Rainscreen air gap.

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Rainscreen gap created by Cor-A-Plast battens with a folded over insect screen at the bottom. Ready for siding.

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3/8″ gap creates a nice drainage space behind this wood siding. I don’t install siding without a rainscreen anymore.

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Face-screwed siding makes it really easy to pull off later if we ever had a reason.

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Rainscreen Wood Siding. Notice the vented roof too.

 

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Foreground: Rainscreen Siding. Background: Cosella Dorkin – Delta Dry Stucco & Stone drainage mat for Stucco.

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Zip Wall got a venting layer before Stucco was installed. Delta Dry Stucco & Stone rolling on here.

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Drainage mat installed and ready for Stucco scratch coat.

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For a more in depth look at the Delta Stucco rainscreen system see this blog post from earlier this year.

Follow this advice and I think Zip is a great system.  By the way, this house blew a .92 ACH50 in our Blower Door test!  Just shy of Passive House standards and 5x tighter than code for Austin TX.  I like an exterior taped system if I can add my extra tips for Durability!

Stay tuned for more on this project.  I’ll be blogging more about this BUILD in the near future.  It’s almost done, but here’s a few pictures of the almost complete house.

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Wood siding has a charred finish called Sho-Sugiban.

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Metal roof, Marvin Windows, and Black Siding. I need to hire a pro to photograph this house!

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Traditional 3 coat stucco with LaHabre integral color finish. Rolling cedar shades look awesome!

PS> I didn’t make specific mention of this in the list, but always… ALWAYS set your windows with a sill pan underneith.  Zip has directions on their site for making window sill pans with their products, or you go with my standard method using DuPont Flexwrap.  No matter your choice of materials, never rely on face sealing alone for windows.  Make a pan so a future window leak will drain to the outside and not get into your structure.

Best,

Matt Risinger – Risinger Homes in Austin, TX

Visit my Blog at www.MattRisinger.com

Risinger Homes is a custom builder and whole house remodeling contractor that specializes in Architect driven and fine craftsmanship work. We utilize an in-house carpentry staff and the latest building science research to build dramatically more efficient, healthy and durable homes.

Be sure to check out my video blog on YouTube

follow me on Twitter @MattRisinger (I’m most active on Twitter)

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Risinger Homes on Facebook.

 

 

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  • Tyler Wingard

    I really enjoy reading your blog, Matt. I hope that going forward more builders will see the need to build for longevity and efficiency and not simply for cosmetics. Thanks for sharing this information. I hope your family has a blessed year in 2015.

    • Tyler, Thanks for your kind words! My hope is that this blog will encourage more builders and homeowners to BUILD with durability and longevity in mind. There is so much price pressure that it’s easy to slip into doing things the “standard” way. We need more people to insist on a higher standard for buildings!
      Thanks again for commenting! Matt

  • David Feldman

    @MattRisinger Very nice job on the blog post. I am in the processes of building a house and noticed the zip system a few weeks ago and was very intrigued by the concept. This helped me decide to use the ZIP system for both the exterior walls and roof. Also a great idea to use Cor-A-Plast for the rain screen. Makes a lot of sense to use that instead of wood that may rot. Keep up the good work.

    • Thanks David! I think it’s a great system that really addresses air sealing very well. Follow my advice and you’ll BUILD a very good house! Best, Matt

  • mlinden

    Matt, great writeup and pics here. You are doing fine job educating homeowners (and maybe some in the industry) of the importance of construction detailing and its long term value. I’ve a couple of questions for you. First, do you think zip system represents the evolution of WRB, and an advance on traditional stapled Tyvek type products and self-adhered and liquid applied WRB products, or does it depend on the project? Second, there seems to be a lot of HVAC plant there – given all the insulation in the SIPS is that homeowner preference or required due to all the glazing? Thanks, and seasons greetings!

    • Thanks for commenting and for your kind words about my blog! On the Zip evolution question: As with many things, it depends. I think the whole industry is (and should be) moving to fluid applied or peel/stick products. WRB’s are just too important to the durability of the house. Higher exposure houses need more “bullet proof” systems. Zip is good under the right circumstances. With a poor install, and a high exposure house I think it’s terrible (as are most products when done poorly on a house with exposure). Example: Don’t use Zip on a house with No or minimal overhangs.
      On the HVAC question, the house is actually pretty good on performance. This house is deceptively large at over 5000SF and we’re using about 5 Tons of AC so we are well over 1000sf/ton of AC. The small compressor is tied to the SD-12 Dehum unit inside. The first split Dehumidifier on the market made by Ultra-Aire. Review coming in 2015 on that unit!
      Best, Matt

      • Jeff F.

        Okay, no Zip on houses with little overhang (my house). I’m planning to replace the horrible hardboard siding on my lowest common denominator builders home with corrugated galvalume siding. I’ve researched a lot, but am not sure what to use for WRB. My plan is to remove the siding and the old Tyvek underneath and then use a board of some kind that will act as the WRB and as a structural substrate for the siding. IE – something that would allow the screws to be set in places that are not studs if needed. Since the screw holding of OSB is not very good and that is what Zip is, I feel Zip is out. Plus you don’t recommend it for short overhang situations. I am now thinking 1/2″ plywood (Plytanium probably) and then cover with Benjamin Obdyke Hydrogap which is approved for metal siding. I’m unsure if the plywood needs sealing and taping or if the Hydrogap alone is enough. Also not sure if we would want to go full rain screen and use the Cor-a-plast. The house is two story and on a hill so it has high exposure to driving rain and very high wind periodically. I want the corrugated steel for durability and esthetics. I know external fasteners are not as good as concealed, but I like the look and cost is a factor.

        • Jeff, Sounds like a cool project! Have you seen my “Perfect Wall” post with that siding? I think your Hydrogap is a good option. Vented Rainscreen is better. Yes on Plywood. I think the exposed fasteners aren’t a big deal when you have an air gap behind them. I wish you the best, Matt

          • Jeff F.

            Excellent videos on the “Perfect Wall”. More food for thought. I appreciate you offering all of us your expertise here. Very helpful and just a downright nice thing to do.

  • jackie

    I really liked the idea of the rolling window shades ( enjoyed the rest of the article too! ). Did you make these up yourself or is it a commercial product ?

  • kingkonger

    Can you follow up on the installation of the insect shield?

    • kingkonger

      Also, did you wrap the base of the zip up and under at all? Or just on the front side? Love this stuff!

  • Arthur Economy

    Hi Matt,
    I will be using CCSF to interior of block wall after framing . What steps should be taken
    To allow drying of block wall ,such as to exterior. I am in hot humid Florida. Would a different approach be advised such as pour in place open cell spray foam inside block
    And if so what should be done to allow drying of block wall. I will be stuccoing exterior
    Block wall.

    Most Grateful,
    Arthur Econonmy

    Arthur’s IPAD

  • Arthur Economy

    Hi Matt.
    Sorry reposted question below to section on ‘Undestanding wapor drive in reservoir cladding ‘

    Thank,
    Arthur Economy

  • Arthur Economy

    Hi Matt,
    Thanks for responding to email question concerning zip sheathing,
    I am expanding question below .

    My project is located in hot humid Florida.

    I am using closed cell spray foam ( demilec heat lock soy 200) for a non
    Ventilated roof assembly and a frame wall. CCSF was chosen to strengthen
    This structures since I am in a 160-180’mph wind zone.

    For both roof and wall zip sheathing will be used.

    On roof I was going to add cosella Dorken delta trela for a ventilated
    Rain screen . I want the CCSF to dry to both sides if needed. I plan
    To use a metal roof. Both zip sheathing and delta trela are vapor permeable
    If I am correct. I have seen contractors put down a non vapor permeable
    Peel and stick product down on similar applications but fell this is a problem
    with CCSF on interior.
    Please advise on best practice for this combination .

    On frame wall I was adding delta dry stucco and stone . This gable end
    Wall starts as second story on top of block wall and will have a slight overhang.
    The wall will sit flush against a first story gable end. Since flashing will
    Take place to adjoin lower story gable roof to new wall would any kind of
    Additional base flashing be needed .I believe drying to both side should work
    fine.
    Please advise best practice for this combination.

    Most Grateful,
    Arthur Economy

    Arthur’s IPAD

  • Robin Bruce

    As it is mentioned above that rain screen built a gap which increases the durability of your home and protects from rain outside of home but temporary walls installed inside also increases the beauty of your home.

  • Seth Tezyk

    Hello Matt,

    Happy Holidays. I’m having a house built using the ZIP System in the Austin/Plugerville area. I decided to go with this regional builder partially based on them using this system and observing that this system has less of chance of mistakes by their sub-contractors then other commonly used systems in my price range. The supervisor is allowing me to add the Carlisle 705 lower wall flashing as you did here. My question is based on the house being clad with brick and stone and the foundation is slab on grade, so there is a ledge for the brick and stone. Would you suggest that the lower wall flashing cover the ledge that the brick or stone will sit on? They have that (awful) plasticized paper running from behind the ZIP OSB over the ledge, so I can also attach the lower wall flashing to that. My question is so I can prevent water getting to the bottom edge of the OSB. Thoughts?

    • JC

      I just watched a video Risinger did on this issue. Comments section suggested that, when using brick, building codes in some areas require that the base flashing to go behind the sheathing. If this is true for your area the inspector may sign off on what you’re suggesting if you provided them with Huber’s technical doc.

      http://www.huberwood.com/assets/user/library/ZIP_Sheathing_Install_Manual-2013.pdf