by • February 13, 2013 • Exteriors - Siding, Stucco, Brick, Stone, Wood, Metal, Insulation & Air SealingComments (32)35769

Exterior Rigid Foam w/ Modern Hardie Plank Siding Details

 I’ve become a big fan of utilizing Outsulation on all my houses over the last 2-3 years.  The building codes are all headed the way of requiring exterior rigid foam (The 2012 IECC will require 1/2″ foam) to boost overall efficiency so I’m really not too far ahead of my time with this building technique. 
  One of the big hassles with figuring out how to install rigid foam is that most window flanges aren’t deep enough to to handle the extra thickness outboard of the OSB/Sheathing.  Here’s a photo of the Andersen 100 windows (which I really like) and their flange depth compared to 3/4″ rigid foam.

The window depth is basically flush with the 3/4″ foam.

This presents a few problems with the added thickness outboard of the sheathing.  One way to solve this would be to use a thick 2x trim around our windows.  Photo below is NOT one of my houses but shows what a thick traditional trim might look like. 

Traditional Exterior design by Seattle General Contractor Ventana Construction LLC

That’s not ideal for several reasons:
1. It eliminates the 3/4″ foam coming right up to the window
2. It makes the house more “Craftsman”-y (I’m not an architect so bear with me)
3. It gives another element that wants to be fiber cement or another rot-resistant material

On this project with Dick Clark Architecture we were looking for a more modern design even though we were using rather traditional 4″ exposure James Hardie smooth siding.  Scott Ginder the project Architect come up with this awesome flashing detail that solved all those problems above.

Rear of the house with Hardie siding above.  EIFS smooth stucco is about to start below. 
The “trimless” windows look fantastic! 

 So, here’s the details of how we achieved this “trimless” window.

The metal flash trim you’re seeing in the diagram above is something we have bent locally.  Watch the video and there are some more detail photos below if you are interested.

Matt Risinger
Risinger Homes in Austin TX
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

Here’s a few photos of the install process.

The sides and bottom of the window get this same profile metal.

We use a little Geocel gutter sealant to keep the corners crisp. 

Finished corner ready to install foam. 

The front of the house has Cumaru hardwood siding we installed vertically.  I’ll save that for a future post.

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  • Your post is so timely with where my husband and I are in our project. We’re in Michigan and currently struggling to find the right windows (for the right price) that help us achieve a modern look. Marvin can accommodate the depth with rigid foam, but they’re pricey. What is the approximate added cost per linear foot for this flange technique? Also is the Hardie on top their pro finished “Iron Grey?” That exactly the color we’re choosing. The architect wanted EFIS, but we opted for a paneled/FRY Reglet bottom.

    • Amy, Very cool that this corresponds to the timing on your project! Let me see if I can answer all your questions. Windows; Marvin is great and I use them alot too. These A100’s are about 10-15% less cost than Marvin Integrity and more like 30% less than Marvin full line. The window metal flashing detail that we use to expand the depth of the windows runs about $2/LF from a sheet metal shop here in Austin. You could bend it onsite with a break too. The Hardie siding we’re showing here is not pre-finished. It’s the traditional painted on site version. I’d love to see some pictures of your install. Best, Matt

    • Amy, I looked up the color on that siding it’s Sherwin Williams Urbane bronze, SW 7048.

    • Thanks a lot for your response. It’s a big help. Our work starts this spring. One other quick comment. I’ve asked contractors in this area about mounting Hardie on furring strips to create the rain screen. Their comment is that the boards could look wavy. Have you ever experienced this? I’d think a rain screen with siding is a good idea no matter where you live. It just helps the home drain/breathe better, right?

  • Nothing like coming home from a 15 hour day at work and seeing a new blog post from you. Now I won’t be going to bed anytime soon lol. That diagram really helps a lot!!! This house looks like it will be a great mix of modern and traditional. Vertical hardwood siding??? Don’t hold out long on us that blog post!!

    • Ryan, that’s hilarious! Glad to hear you’re ditching prime time TV in favor of my blog! That vertical siding is pretty sexy. I didn’t shoot any video on the install, but I’ve got some progress pictures and I’ll do a post on that in March sometime. Appreciate you commenting buddy. Matt

  • Hi Matt-

    Love your blog. When are you going to get to that long promised Andersen 100 review? I’m about to spec windows for my new house and I’d like to know what you like so much about them.

    Love the Outsolation details on this house. Great tip.

    • Peter, Appreciate your kind words! I’ll get on the A100 Review. It’s really the best window for the money. You could spend more and get a window that looks nicer but doesn’t perform any better. You could spend less but get much less in terms of overall longevity/performance/looks. Look for my post shortly on that topic. Best, Matt

    • Can’t wait. Keep up the great work. You’re providing an education for untold builders all across the internet.

  • Beautiful! Love the modern design with a material that is thought of as “traditional”.

  • Hi Matt, On your May 30 blog about RainScreens you wrote, “You can’t nail the siding because you rely on the fastener shear strength so in this case we used 4″ deck screws, countersunk the screws and used bondo to cover the fastener heads. The foam can handle 25psi of pressure so the screws hold the assembly very tightly in compression.”
    Does this apply to all applications or just the pine job you were doing? I’m curious if you screw all HardiePlank installations using this RainScreen process. If you do screw, do you have to pre-drill the HardiePlank?

  • Tammy, Sorry for my slow reply. I’m still catching up from vacation over the July 4th week. That’s a great question. In the blog you mentioned we were using 1″ rigid foam, plastic battens, then wood siding. We had to use very long screws to screw the siding into the studs. In the blog post above we are using 3/4″ rigid foam, then the same 3/8″ plastic battens, then Standard Hardie. This can be nailed conventionally. Hardie can be screwed but it’s very time consuming and frankly not fun/easy. If you are using thicker than 3/4″ foam I’d recommend using 1/2″ plywood battens or 1×4 pine battens that can be screwed to studs then you can nail your Hardie to the battens conventionally. Make sense?
    Best, Matt

  • Hi Matt– can provide more info on the metal flash detail you used? what gauge, metal type, leg length, etc. Also did you paint it on site? Thanks

  • Peter. That’s 24ga flashing, the metal is “Paint Grip” which is a matte finished primer that accepts paint. We didn’t paint it and left the bare primer. The legs stick out about 3/4″ to 1″ from the siding and window. My preference is to get these flashings in Galvalume which should last 75+ years without paint or rust. Best, Matt

  • Thanks!

  • This is very nice, and cudos for being a bit ahead of the codes, its the right way to build when it comes to insulation.
    One thought to save some money for those that have seen it done. Rmax has great Tapes and Flashings (R-SEAL Construction Tape and R-SEAL 6000) which can be used to make the foam sheathing a fullly tested and approved WRB. That means, you can get your waterproofing and outside insulation from the same system, saving the duplication of a WRB (Water Resistive Barrier) under the insulation. It acts as an Air Barrier as well when properly taped and flashed, saving money in materials and labor.
    I like that you take advantage of the foil facing of the rigid board to give the radiant barrier. Many dont take advantage of that property by adding the air space between the siding and foam board!! Small details that make a big difference.

    • Thanks Martin! Yes the small details make a huge difference. I’m not a fan of using the foam face as the WRB but I know that some big names promote this concept. Joe Lstiburek has shown this detail in his presentations. I tend to be a belt/suspenders guy, and I also tend to have clients who allow me to spend the extra $$$ on the things that I’m finicky about. Best, Matt

  • Lawrence Fruit Tree Project

    What does the detailing for the top of the window look like? How does it channel water away from the side trim? can water travel inward between the bottom flashing and the window?

    • If I understand your question correctly you are asking how the head flashing protects the window? So, first I install the windows using the DuPont Tyvek approved methods & materials. Then, I make the flashings starting at the bottom and working my way up to do the head flash last. The head flash overlaps the side flashings. We don’t caulk the assembly so water can drain out and it can dry. Does that answer your question?
      Thanks, Matt

      • Lawrence Fruit Tree Project

        Great blog by the way, your videos are well done and easy to learn from. I will clarify my question again. Is the head flashing made from the same profile as the side and bottom flashing? When water hits the top of the head flashing it can move either forward (falling in front of the window) or it could drain to the left and right of the window, moving down the outside of the side flashing and potentially entering behind the siding at the inside corner of were the siding wraps the junction of the side and bottom flashings. Is that statement basically true? Also can water hitting the top of the bottom flashing move horizontally inward between the window and the flashing? Is any caulking used here? Are the top or bottom flashings angled to shed water? Is the rigid foam have taped joints to shed water? what product is used?
        More specific detail drawings would be useful in a future blog post. Thanks.

        • Ok that clarifies. The head flash is angled toward the front but would could get down the sides. I’m a big advocate of waterproofing at the WRB layer then using a rainscreen siding install. That way any water can get out & all the claddings/foam can dry. I’ll do a future post with some great details on the flashing. Thanks for your kind words and for reading my blog. Best, Matt

  • Gary Birtles

    I really like that dark brown hardwood siding. I usually think of wooden siding as more of a cabin look, but in this setting, it gives the house a chic, modern feel. It is totally my style, sleek and clean.

  • Karl

    What is the colour of the hardie cladding called?

  • Jenny

    Hi! My husband and I live about an hour and a half south of Austin and are replacing the brick veneer on a pier and beam house we moved to the country with cedarmill hardie siding. The question we have is what materials and in what order to we put them on under the siding. The house currently has some sort of mdf type sheets over the studs covered with thick black paper. We were considering replacing the mdf stuff with 1/2 plywood, followed by a rigid foam insulation and then Tyvek house wrap. Is this best for our hot and humid climate? Also do we need to install wooden strips between the tyvek and siding to create an air space? Sorry for the million questions. We are doing it ourselves and my husband is used to building metal buildings…we have never worked with hardie before.

  • JW Anderson

    Matt, Im a DIYer who would like to know more about the metal flashing ie type of metal etc and detail on the inside and outside corners for this system maybe what that metal flashing looks like. Do you have any photos or other detail to share. I like this system and think it would be awesome for central georgia. Would like to go to a small home with exterior foam and hardie but want to ensure I understand the details. Also do you caulk seal behind the metal flashing? thanks a bunch JW

  • Chris Petrillose

    I just came across your blog and I am very impressed with your skill set and knowledge. I am currently building a new home in central New York and plan on incorporating several of your concepts. I am curious where you got your metal flashing that you are using for around the windows? I am planning on using 2 layers of rigid foam on the exterior with LP Smartsiding lap siding. Would you recommend a wider piece of flashing? CP

    • Chris, Thanks! I get my flashing bent at a local roof supply house that does metal flashings to order. Yes, go wider. Your roofer can do this for you too. Best, Matt

  • Chad Gould

    Hi Matt, thanks for the great information. I was wondering if you have a recommendation on the gauge and the base material for the metal flashings?

    • I would recommend a 26ga metal like Galvalume. Best, Matt

  • Ruth Hull

    Hi Matt, we were looking to purchase a home in Eastern Oregon that was built in 2004, and just found out it was not wrapped behind the Hardy Plank. Will become a issue down the road, and do you know when it became code to wrap a home.

  • Vick

    Matt, great blog and videos on construction techniques and products. I have an older early 80s house with T-111 siding that really needs replacing. I have decided to use a Hardie board lap-side finish and would like to use a 1″ exterior foam to insulate before I install the Hardie siding. Several questions:
    1. I would like to leave the old T-111 in place since there are no structural issues with it and a lot of labor to remove. OK?
    2. Would like to Tyvek over the T-111 as a vapor barrier. Assume this is ok?
    3. Then add a 1″ exterior foam on top of Tyvek. Do I need a gap between?
    4. Will install Hardie board on top of rigid foam. Can I install directly on top of rigid foam?

    Thanks for your help!

  • Twinoaks

    Matt I’ve watched several of your videos and have enjoyed them. This has been a few years ago is this still your preferred method for rain screen over insulation or do you recommend another now.also can you post detail of your corner “x” flashing.