This was very interesting. But may I suggest a slight addition to the water damage test? - first, use a caliper to measure the diameter if the wood at the same time frames and then give the wood a couple of days to dry and then measure again. This will show the delamination of the edges damaged by water. - second, perform another nail pull test on the water saturated edges of the panels. Both when wet and after given the time to dry. Do this pull test near the edge since this is where the panels will be nailed to the rafters. - second PLUSS, knowing that material is nailed along it's edges to secure it to the rafters, put a nail half way through the panel within the nailing area (~0.5") along the edge. THEN try to pull the nail horizontally through the wood. As the nail would go if the wood i pulled into the span to see what the rip out strength is.
I 100% agree with the results but disagree with the Superiority of the OSB! Here in the Philippines, the primary feature that we need is the Pull-Out rating because we have many Strong Typhoons that can fly our roofs. Second, we can just buy a very cheap "WATERPROOF" Underlayment in between a standing seam roof and a 3/4 Marine plywood.
I think you should have measured the thickness of the different samples after water absorption, and then measured them again after a complete dry. The primary issue with OSB is its multi strand makeup. You have many layers of glue delaminating at different rates. OSB that has been saturated with water will never return to it's original thickness. Plywood is far superior in this regard.
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!!!!
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.
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.
Agree, the plywood will dry out faster and retain it's shape once it had dried, but the OBS will swell (especially at the ends), and will never go back. It mainly comes down to how well your underlayment can protect the wood.
@@OnlineAutoRepairVideos I have never understood how underlayment can protect the deck given that it is penetrated by about 250 nails per square, and every penetration can leak.
The water test was flawed. If roof sheathing gets wet it is usually the entire surface that gets wet. The end grain of wood absorbs water more easily than the surface of the board. if the OSB laid in the water for 4 days it would swell up like a pig, and remain that way after drying out. Good quality plywood would swell much less and regain its dimensions when dried out.
I've never ever used osb in the 16 years of remodeling houses in North Jersey. I wouldn't even use it as a pad for heavy objects. Put both osb and plywood out flat in the spring for a month. The CDX would be absolutely fine and you could use it again. OSB'd be a piece of soggy cardboard ready for the dumpster. It's highly inferior. Takes more toxic glues to hold its form and those OSB sheets need to off gas which they'll do really well in your brand new home wrapped in tyvek and pumping toxicity through the house's HVAC system. There are studies that show that children who grow up in homes like these have body and brain dysfunction along with cancers.
I 100% agree with the results but disagree with the Superiority of the OSB to be used for roof deck! Here in the Philippines, the primary feature that we need is the Pull-Out rating because we have many Strong Typhoons that can fly our roofs. Second, we can just buy a very cheap "WATERPROOF" Underlayment in between a standing seam roof and a 3/4 Marine plywood.
Thank you for your testing. Although you did compare pricing it does seem that it depends on what you want from the sheeting. I looked at this because of redoing my bicycle shed which has transparent corrugated sheeting that cracked and broke through here in London GB. I think I will go with the usb and glue shingle felt on. Thanks very much. keep them coming.
for the water test you should have tested how fast each one dries out. The problem with OSB is it gets wet and stays wet. In the same way that the plywood draws it water, it also has a passage to dry out. So when the OSB gets wet, it stays wet which really causes the damage. When plywood gets wet, it dries much more quickly. Also known as hygroscopicity or drying potential.
Your results are exactly as I would have expected. And that’s why my home is OSB. I mainly used it re the water retention and rot potential. It was also nice to save about $300 in cost.
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.
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.
Plywood is better for roof decking and sub floor. Osb is fine to use for wall sheathing if you have large overhangs and there is little to no contact with moisture. If there are smaller overhangs on the builing and the walls will get wet often, then use plywood for the sheathing. I say better bc osb does not do well with long term moisture exposure, it us much harder for good plywood to rot
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.
Are those shank nails or just regular smooth nails in the beginning? Hard to tell from the video. I always choose OSB for roofing but around here. Due to code and regulations, we have to use 5/8 OSB minimum. Just remember, you can always do better than code, code in the minimum guideline.
Great analysis. Agree with your "weighting" decisions, even though they all favored OSB. For roofs, it's all about the water (unless you live in Buffalo, then it's all about the weight of the snow).
The more water osb absorbs the slower it releases where as plywood releases water faster. De-lamination is a material deficiency not a difference between osb/plywood. Plywood excels compared to osb when wet, for decking and fastner retention.
That was a nice try. Exterior grade 1/2" plywood lasts much better long term in wet conditions. Where I live in Canada OSB just swells up and never goes back to original thickness when it dry's out. Also it loses strength after it swells up and disintegrates. Its cheap for a reason. I would never sheet a roof here with OSB.
Quality fir not yellow pine plywood wins in my opinion. I've seen pieces left outside for months or even years and all that happens is it turns gray, it doesn't even warp that badly. Try that with osb and it will turn into a piece of sponge cake.
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)
Helena took my roof. I wanted 3/4" plywood. After watching I still want 3/4" plywood. I'm 250lbs and I don't like to feel my feet sink when I'm on the roof.
You didn't really test the water correctly. The plywood may have absorbed more, but what was its shear strength before and after the water absorption? From my experience, OSB turns to mush, and plywood will rot over time. Neither a great outcome, but the plywood seems to be a stronger product if installed with proper waterproofing.
I'm not convinced. Standing on wood does not tell me the stresses and movement of roof decking, how it holds to the substructure, how it holds shingling nails over 30 years and how it degrades when moisture gets to it. I want to see the results of 30 years application, and also the faults that occur with sub-par building skills. (I expect some decking is not applied in the best manner.)
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.
![I.N "HALLUCINATION" | [Stray Kids : SKZ-PLAYER]](http://i.ytimg.com/vi/n5B5q1Hwt_U/mqdefault.jpg)
Do you agree with the results of this challenge? Let me know👇
This was very interesting.
But may I suggest a slight addition to the water damage test?
- first, use a caliper to measure the diameter if the wood at the same time frames and then give the wood a couple of days to dry and then measure again. This will show the delamination of the edges damaged by water.
- second, perform another nail pull test on the water saturated edges of the panels. Both when wet and after given the time to dry. Do this pull test near the edge since this is where the panels will be nailed to the rafters.
- second PLUSS, knowing that material is nailed along it's edges to secure it to the rafters, put a nail half way through the panel within the nailing area (~0.5") along the edge. THEN try to pull the nail horizontally through the wood. As the nail would go if the wood i pulled into the span to see what the rip out strength is.
I 100% agree with the results but disagree with the Superiority of the OSB!
Here in the Philippines, the primary feature that we need is the Pull-Out rating because we have many Strong Typhoons that can fly our roofs.
Second, we can just buy a very cheap "WATERPROOF" Underlayment in between a standing seam roof and a 3/4 Marine plywood.
I think you should have measured the thickness of the different samples after water absorption, and then measured them again after a complete dry. The primary issue with OSB is its multi strand makeup. You have many layers of glue delaminating at different rates. OSB that has been saturated with water will never return to it's original thickness. Plywood is far superior in this regard.
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!!!!
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.
thank you for your support!
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.
Outdoor rated plywood? Is that pressure treated?
@@RoofRepairSpecialist Exterior grade plywood
@@RoofRepairSpecialist Hmm... that's a good point. Was the plywood you tested exterior-grade as required by most codes, I think?
Agree, the plywood will dry out faster and retain it's shape once it had dried, but the OBS will swell (especially at the ends), and will never go back. It mainly comes down to how well your underlayment can protect the wood.
@@OnlineAutoRepairVideos I have never understood how underlayment can protect the deck given that it is penetrated by about 250 nails per square, and every penetration can leak.
The water test was flawed. If roof sheathing gets wet it is usually the entire surface that gets wet. The end grain of wood absorbs water more easily than the surface of the board. if the OSB laid in the water for 4 days it would swell up like a pig, and remain that way after drying out. Good quality plywood would swell much less and regain its dimensions when dried out.
I've never ever used osb in the 16 years of remodeling houses in North Jersey. I wouldn't even use it as a pad for heavy objects. Put both osb and plywood out flat in the spring for a month. The CDX would be absolutely fine and you could use it again. OSB'd be a piece of soggy cardboard ready for the dumpster. It's highly inferior. Takes more toxic glues to hold its form and those OSB sheets need to off gas which they'll do really well in your brand new home wrapped in tyvek and pumping toxicity through the house's HVAC system. There are studies that show that children who grow up in homes like these have body and brain dysfunction along with cancers.
@@mattski1979 Thanks for this reply Sr. Was handy !
@@mattski1979damn
Never though of it like that
I 100% agree with the results but disagree with the Superiority of the OSB to be used for roof deck!
Here in the Philippines, the primary feature that we need is the Pull-Out rating because we have many Strong Typhoons that can fly our roofs.
Second, we can just buy a very cheap "WATERPROOF" Underlayment in between a standing seam roof and a 3/4 Marine plywood.
Thank you for your testing. Although you did compare pricing it does seem that it depends on what you want from the sheeting. I looked at this because of redoing my bicycle shed which has transparent corrugated sheeting that cracked and broke through here in London GB. I think I will go with the usb and glue shingle felt on. Thanks very much. keep them coming.
for the water test you should have tested how fast each one dries out. The problem with OSB is it gets wet and stays wet. In the same way that the plywood draws it water, it also has a passage to dry out. So when the OSB gets wet, it stays wet which really causes the damage. When plywood gets wet, it dries much more quickly. Also known as hygroscopicity or drying potential.
Your results are exactly as I would have expected. And that’s why my home is OSB. I mainly used it re the water retention and rot potential. It was also nice to save about $300 in cost.
The osb swelled up in the water. It also turns to mush and eventually delaminates.
I agree, it just doesn’t delaminate the entire sheet
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.
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.
Great to hear!
Plywood is better for roof decking and sub floor. Osb is fine to use for wall sheathing if you have large overhangs and there is little to no contact with moisture. If there are smaller overhangs on the builing and the walls will get wet often, then use plywood for the sheathing. I say better bc osb does not do well with long term moisture exposure, it us much harder for good plywood to rot
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 love this channel! Just subbed! Thanks so much 🙏
Awesome, thank you!
Are those shank nails or just regular smooth nails in the beginning? Hard to tell from the video. I always choose OSB for roofing but around here. Due to code and regulations, we have to use 5/8 OSB minimum. Just remember, you can always do better than code, code in the minimum guideline.
what thickness osb and plywood did you test ?
Great analysis. Agree with your "weighting" decisions, even though they all favored OSB. For roofs, it's all about the water (unless you live in Buffalo, then it's all about the weight of the snow).
On the East coast here OSB is king but OSB getting wet then drying will crumble like the saw dust it is .
If you a DIYer plywood all the way
The more water osb absorbs the slower it releases where as plywood releases water faster. De-lamination is a material deficiency not a difference between osb/plywood. Plywood excels compared to osb when wet, for decking and fastner retention.
I was a rough farmer for 20 years. Osb is better in every way.!
Thanks!!.........this helped a lot !
My pleasure
How about 1 pallet high instead of 3?
Perfect, thanks bro 🙏
My pleasure!
That was a nice try. Exterior grade 1/2" plywood lasts much better long term in wet conditions. Where I live in Canada OSB just swells up and never goes back to original thickness when it dry's out. Also it loses strength after it swells up and disintegrates. Its cheap for a reason. I would never sheet a roof here with OSB.
It’s pretty much the same price in our market
Plywood costs more expensive for a reason, because it's better. Only one thing is good on OSB, is that it stays straiter when you work with it.
Quality fir not yellow pine plywood wins in my opinion. I've seen pieces left outside for months or even years and all that happens is it turns gray, it doesn't even warp that badly. Try that with osb and it will turn into a piece of sponge cake.
Didn’t even know there was a difference, we may not have that in our area
*More glue is used in Plywood. If they used the same amount of glue in the OSB it would do just as well.*
How thick was the plywood OSB you tested. I didn’t catch that anywhere…
1/2 actually 15/32
I already knew these properites of OSB and plywood but I just had to see if this guy falls. Thanks for the demonstrations. 😅
You bet!
Agree
Thanks
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)
I agree, wouldn’t say I’m a fan boy, but I do lean towards OSB.
Helena took my roof. I wanted 3/4" plywood. After watching I still want 3/4" plywood. I'm 250lbs and I don't like to feel my feet sink when I'm on the roof.
That would definitely be nice!
You didn't really test the water correctly. The plywood may have absorbed more, but what was its shear strength before and after the water absorption? From my experience, OSB turns to mush, and plywood will rot over time. Neither a great outcome, but the plywood seems to be a stronger product if installed with proper waterproofing.
Particle board turns to mush. Osb peels to long flakes.
Thank you so much for showing me the video it really helped me choose which one I'm going to use
No problem 😊
I'm not convinced. Standing on wood does not tell me the stresses and movement of roof decking, how it holds to the substructure, how it holds shingling nails over 30 years and how it degrades when moisture gets to it. I want to see the results of 30 years application, and also the faults that occur with sub-par building skills. (I expect some decking is not applied in the best manner.)
In test 2 if the OSB stays in water long enough it will come apart. OSB is better for the most important reason, cost.
It’s pretty much the same price in our market
And yet another video ruined by the ignorant dubbing in of some annoying, obnoxious, crappy-ass "music". Big thumbs down goes to this channel!
That shit ass "music" got progressively worse making the rest of the video unwatchable. Dude, don't quit your day job.
lol, what are you talking about
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
Subtly showing off his finger strength.
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.
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.
Worst thing ever?
I have witnessed termites eating osb flooring!
OSB is trash