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LP Smartside with a rainscreen – adviseable, or no?

grmp945 | Posted in Green Products and Materials on

Hi all,

I’m in CZ2 and have a building sheathed with zip panels. I am ready to install siding and am considering using LP Smartside panels or lap siding.

I spoke with LP tech support and they claim that their SmartSide siding does not need a rainscreen and that their 50-year warranty will be honored if the siding is laid directly on sheathing.

What do you all think? Will engineered wood products like LP SmartSide benefit enough from a rainscreen to make the extra time and money worth it? Maybe the siding won’t rot if installed without an air gap, but what about paint – how much longer would it last?

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  1. Expert Member
    Dana Dorsett | | #1

    The purpose of a rainscreen is more to protect the structural sheathing & wall assembly more than to protect the siding or paint (though it does all of the above). A rainscreen is a powerful capillary break between the siding & sheathing layers, and improves drying rates for both.

    In any location/climate where rain &/or dew wetting of the siding is common, including a rainscreen is going to be "worth it" in the long term.

  2. Expert Member
    RICHARD EVANS | | #2


    I would never build a house without a rainscreen gap. It's cheap insurance. If the OSB becomes wet due to bulk rain water, vapor transmission, flooding, sprinklers, etc; then you will give it a chance to dry out with the gap.

    LP's first engineered product failed and resulted in lawsuits. Their new product is excellent but they aren't taking any chances with their warranty. I installed our LP smartside over 1x3 furring strips. I used stainless steel, ring shank coil siding nails. The siding is bomber but will not be covered under warranty. They wanted framing nails hitting studs,etc. With 5/8" plywood, it was overkill.

    I trust the product enough that I gave up on the warranty. As Tommy Boy once said... " You can get a look of a cow's..."

    1. Expert Member
      MALCOLM TAYLOR | | #3


      It seems counter-productive and a bit backwards to me that a manufacturer would make a product the then needed major modifications to the rest of the building to meet warranty. It effectively means using it on most re-siding jobs wouldn't fly. A real cart pulling the horse way of doing things.

  3. PensacolaPI | | #4

    Agree with Rick, cheap insurance and a no brainer. Murphy’s Law comes to mind for some reason. We are starting a new house within a few months and using LP and will use one for sure.

  4. grmp945 | | #5

    Everyone - thanks a lot for the replies!

    OK then - I'll be using a rainscreen!

    I'm thinking of using either MTI's corrugated lath strips or Cor-a-Vent's sturdi-strips. MTI's product is available as either 1/8" or 3/8" deep, and Cor-a-Vent's strips are 3/8" deep. Any thoughts on using the 1/8" vs the 3/8" product?

  5. PensacolaPI | | #6

    I’d go 3/8” but that’s me.

    1. Expert Member
      MALCOLM TAYLOR | | #7

      I agree. At 1/8" you would be lucky to maintain a cavity or capillary break, and the amount of ventilation would be negligible.

  6. Roger_S39 | | #8

    Hi Nic,

    Purely as an effort to learn and hear ideas and thoughts, any chance you can share your thinking on going with the above mentioned product over others - fiber cement board etc.

    Thank you.

    1. grmp945 | | #9

      Hi Roger,

      Caveat: I'm not a professional, let alone an expert!

      From my perspective, I like LP smartside over fiber cement board because it is simply easier for me to work with: I can cut it just like wood with no special tools or much less worrisome/hazardous dust. LP Smartside is also lighter, easier to handle (bends without breaking), and possibly less expensive compared to fiber cement. Also, I'm using 4x8 panels - in fiber cement, these are too heavy for me to work with alone, but the smartside panels are doable by myself.

      Here is a good recent video comparing the two:

      Also, for the horizontal lap siding, there is a brand new feature: a shiplap edge. Previously you had to caulk or flash between pieces, but the new shiplap edge allows for a faster, simpler installation. You can see it at 10:06 in this recent video:

      1. Roger_S39 | | #10


        Good points.

        Thanks for the reply and all the best with the project.

  7. walta100 | | #11

    After see LP siding on my friends house fail miserably after only a few years followed by 5 years of paperwork pointless delays. The settlement seemed very small considering the work required.

    Given the small price difference I would avoid the product.


    1. monkeyman9 | | #12

      Curious how it failed? Did it delaminate or expand or? And was it newer smartside or the older stuff that all failed.

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