Attaching siding to 1×4 battens (furring strips)
cragged
| Posted in Building Code Questions on
I am interested in having 8″ smart side lap installed on a rain screen made up of vertical 1x4s. The LP application guidelines say the following: The framing shall be of adequate thickness to accept one and a half inches of nail penetration. I am using one and a half inch roxul and the stud spacing is 16″. I feel confident this would work fine but how many contractors will do an installation that doesn’t follow the manufacturer’s policy. Also would this be a violation of general building code? The nail penetration would be three quarter inch. My windows aren’t built out enough to use 2x4s as battens.
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This might help: https://lpcorp.com/resources/product-literature/technical-notes/tn-018-siding-on-insulation-over-furring-strips/
It looks like you're good to go with your 1x4 at 16" O.C. based on that addendum. The addendum does say it is expired, so maybe if you want to really make sure you're in the clear, track down an updated version.
Cragged, most people who install rain screen battens use long screws, especially with Roxul as it's more compressible than rigid foam, and then fasten the cladding to the battens. If you think you might not be meeting the manufacturer's specs, you can contact their technical services department. I have usually found them to be very helpful. Or you can disregard the specs, but if anything goes wrong you would not have recourse. Personally I would feel comfortable fastening Smartside to 1x4's but I would want the 1x4's to be fastened to the studs with 1 1/2" penetration.
It's very common with exterior insulation to build out the windows with exterior extension jambs and sill extensions, by the way.
This is Craig McCormack. I am using heco topic therm screws so the battens are well attached to the studs. Would a contractor want to install a product against the policy of the manufacturer?
Craig,
Call up the manufacturer (LP) and talk to an engineer or technical help specialist.
If this were my house, and a certain siding manufacturer did not allow installation over 1x4 battens, I would choose a different type of siding.
Cragged, check the link I posted. I'm pretty sure that addendum specifically allows what you are trying to do. Always worth calling LP to double check of course.
This is Craig McCormack. I talked on the phone with the tech person at LP Smartside and he said no way no how would he say yes to my plan. I talked to the local building inspector and he said he couldn't understand why three quarter inch of wood isn't good enough.
Craig, then your options are to ignore the manufacturer, change to 2x furring (and associated window extensions), or change your siding material. Which of those appeals to you?
I am leaning toward ignoring the manufacturer because I don't believe the battens would ever cause a warranty issue. If the prefinish is bad I suppose they could say the battens void the warranty for the factory paint job. I will also have to find a contractor that doesn't care about the siding company's directions.
Hi, I am in an identical position as Cragged. May I ask where I might find more information regarding screw size, length and spacing through the 2x4 battens into studs and exterior extension jambs and sill extensions. We were planning to have existing trim wrapped with aluminum.
User-6991758,
For information on furring strip fasteners, see Fastening Furring Strips to a Foam-Sheathed Wall.
For information on exterior jamb extensions for outie windows, see:
‘Innie’ Windows or ‘Outie’ Windows?
Installing Windows In a Foam-Sheathed Wall
GBA Details for innie and outie windows
JLC: Installing Exterior Insulation in Cold Climates
REMOTE: A Manual
Windows Can Be a Pain
Thanks Martin. I will research and get back with any ?s.
A bit off topic, but maybe helpful .... found out that Smartside released a technical note #18 specifying the ability to use 1x4 furring strapping instead of 2x4 wby increasing from one to two nails per lap through foam/mineral wool greater that 1".
https://lpcorp.com/resources/product-literature/technical-notes/tn-018-siding-on-insulation-over-furring-strips/