Do you agree with the results of this challenge? Let me know👇

This was a good comparison, I absolutely do not think you're wrong. I resheathed my entire roof with 19/32 OSB and I don't regret it. Thanks for this great comparison, I've learned so much from this channel alone that I wouldn't have been able to replace my roof by myself without the Roof Repair Specialist. You saved me about $20,000. I owe you!!!!

Very interesting. But, what kind of plywood were you testing? Standard plywood is not meant for any kind of exterior use. CDX plywood can be used for walls and roofs, but still is not appropriate for longer-term exposure to moisture. Exterior plywood is appropriate for continued moisture exposure. If you see plywood roofs delaminating, that might be regular plywood or even CDX, but it wasn't likely exterior-grade plywood. CDX plywood does not absorb water as readily as regular plywood, and exterior plywood does not absorb water easily, likely less than OSB but I don't know for sure. It also dries faster than OSB. OSB is prone to edge swelling with repeated cycles of wetting and drying and more so than any of the plywoods. So the question is: how bullet-proof do you want the roof deck to be or how bullet-proof does it need to be? If you don't want to worry about absorption by the roof deck, delamination or termite damage, then exterior plywood is the way to go. It is a one-and-done solution. CDX will help if there is rain before the shingles are applied, but it will not hold up to long-term moisture exposure. OSB wets more slowly but also dries more slowly. It is also prone to edge swelling. OSB is most cost effective, is certainly better than standard plywood and perhaps also better than CDX. Exterior plywood will last long-term without delamination, but it is more expensive, though if it saves you from replacing the decking later, it is more economical. It's always about tradeoffs. Exterior plywood can't be in direct contact with aluminum, so best to use I&W shield between them. Also hot-dipped galvanized or stainless-steel fasteners should be used. Exterior plywood is also immune to termite damage. It is twice the price of OSB, but on a recent roofing estimate, the cost of replacing decking would be $50 per sheet plus the cost of the material. For all the videos of degraded, delaminated, rotten roof decks I've seen, it might be worth it to use exterior-grade plywood.

This is an outstanding group of tests that show the strengths of each type of wood choice. I was surprised and educated. Thank you for always impressing me with your practical knowledge and experience.

I love this channel! Just subbed! Thanks so much 🙏

Outdoor rated plywood is better because OSB will weaken and come apart if rained on before applying shingles. If the plywood gets wet before shingling, no big deal. Just wait until it dries out on sunny day, and apply shingles.

Thanks for this. I have OSB on my shed roof and there's been some slight water damage at the drip edge. Your tests help me understand what I need to do when I repair my roof.

This may not be relevant but there have been cases when balcony supported by engineered wood collapsed. The reason is when engineered wood get wet the water is trapped and can't dry out, which eventually leads to rotten wood.

I already knew these properites of OSB and plywood but I just had to see if this guy falls. Thanks for the demonstrations. 😅

Agree

The osb swelled up in the water. It also turns to mush and eventually delaminates.

How thick was the plywood OSB you tested. I didn’t catch that anywhere…

Thank you so much for showing me the video it really helped me choose which one I'm going to use

Most of these aren't real world scenarios. Maybe nail plywood over a wall and measure how much pressure it takes to break, but really only relevent for the roof. The plywood should be tested to see how long it takes to disintegrate, but again only good to know for how long it can last before you need to repair it-if you have a water problem it needs to be fixed sooner rather than later. Is that 1/2" plywood true 1/2" or is it 7/16? Down south they call the 7/16 plywood 1/2 inch, and you can't even buy the 1/2 inch down at the box store. Also, just because plywood holds nails better, doesn't mean it's necessary. I've never had a shingle blow off in 35 years, and when I see roofs that do, it's because someone blew right through the shingles with the nail gun.

Osb is cheaper and cheaper to make so making money for manufacturers

OSB is highly flammable and weak, off gases more, and dimensionally unstable when it gets wet. It’s the worst thing ever for building homes.

I think osb is stronger. I always paint my sub floor as soon as i put it down to keep the weather from affecting it. I only use 5/8 inch on roofs.

I love how when plywood wins a round, you nullify it and downplay its win, but when OSB loses, you nullify it and downplay the loss.. just admit you're a OSB fanboy... You keep finding excuses to let the fat kid win the race on foot against the skinnier faster kid... I don't see how OSB is superior to plywood period... There are 2 WaWa gas stations being built in my area and the sheathing around the building as well as the sheathing/roof decking is all plywood... and its plywood for a reason(s)