Wanting to install some 1/8" thick shiplap plywood over the top of some hardie board 4x8s on my patio ceiling to freshen it up. Can I use a brad nailer for this or do I need something more stout?

I'd recommend a finish nailer in lieu of a brad nailer. My main concern would be the brad nail's holding strength, especially with full sheets of plywood hanging overhead.

They'll be cut to 6" strips and only 1/8" thick. Prob 4-6 nails per. Think that'd be an issue?

Mostly concerned if a Brad nailer will penetrate hardie

Brad nailer will penetrate the hardie but you need to nail it into the studs for it to hold. Hardie alone won't give you enough strength with any nails.

I wouldn't trust a brad nailer even cut into strips. Great for trim though. You could always throw a piece up there with your Brad nailer and give it a pull to gauge for yourself.

If you don't own a finish nailer, you can rent one from most tool rental places if you don't want to invest in one.

1/8 plywood on an exterior application will more than likely warp/buckle from humidity and gravity. The nail will hold as long as your are penetrating the ceiling joist behind the hardie with proper spacing. Most hardie soffit is 5/16 plus 1/8 plywood would recommend at least 1 1/4 inch nail but 1 1/2 would be better. More than likely it will warp/ buckle but if you want to attempt then I would apply liquid nails to the back of the plywood before installing it.

I agree 100% with this.

I think though, rather than liquid nails, I'd go with flooring adhesive spread on the ceiling. Then your nails are only to keep everything in place until the adhesive drys

Thanks y'all. Planned on coating all sides of the plywood to prevent warping. Liquid nails and Brad nails into studs sounds like a solid combo.

Why don't you just put some hardi or LP smartside over the 4x8 paneling? Why go to the trouble of sealing an inferior product?

I don't want to sound critical, but what you are planning to do sounds like a really bad idea.

Sorry, I didn't see that it would be on the ceiling. I thought you were doing this on the wall. That why it seemed really strange to me. Seems that you could do beaded plywood on the ceiling but I would definitely use a finish nailer with glue. Make sure the nails don't shoot through the plywood. Try to make them hit the joists.

What do you mean hardi over the decorative shiplap? I was planning on doing the exact same but afraid there no 'hold' on the hardi. The liquid nails makes sense to me.

I'm not the Op but was thinking this over hardi

100% that. Looks badass to me. Would be more a natural color. Any other recommendations?

That is 3/4" tongue and groove

No need to use any liquid nails if installing that

But you need to make sure your nails penetrate enough past the hardi into the ceiling joist to hold it securely


A Brad nailer is a little small for 3/4 inch tongue and groove. Normally it is blind nailed it with a 16 gauge nailer

Got it, probably a little more spendy but I will investigate.

I also found this, would have the same effect. Need to get some long construction screws and would just lay it over the existing hardie panels.

https://www.homedepot.com/p/James-Hardie-HardiePanel-HZ10-5-16-in-x-48-in-x-96-in-Fiber-Cement-Sierra-8-Panel-Siding-9003080/305684630

The more I think about it the more I realize that an 1/8" plywood sheet would have the least impact on all my existing electrical fixtures. Otherwise I am paneling over existing ceiling fan boxes and outlet boxes with another 1/2" of hardie. I do not want to have to demo the whole thing.

Longer screws and electrical box extenders


https://www.amazon.com/ARLINGTON-INDUSTRIES-Single-Gang-Extender-Heavy-Duty/dp/B00PSMS9QW/ref=asc_df_B00PSMS9QW?tag=bingshoppinga-20&linkCode=df0&hvadid=80126962351859&hvnetw=o&hvqmt=e&hvbmt=be&hvdev=m&hvlocint=&hvlocphy=&hvtargid=pla-4583726541012723&psc=1


This is done all the time when back splashes get tiled

You are amazing. Thanks for teaching a newbie.