LP Smartside with a rainscreen – adviseable, or no?
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?
GBA Detail Library
A collection of one thousand construction details organized by climate and house part
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.
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..."
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.
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.
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?
I’d go 3/8” but that’s me.
I agree. At 1/8" you would be lucky to maintain a cavity or capillary break, and the amount of ventilation would be negligible.
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.
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:
Thanks for the reply and all the best with the project.
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.
Curious how it failed? Did it delaminate or expand or? And was it newer smartside or the older stuff that all failed.