Closed Cell Foam - Does it add strength? Let's Test!

[@AgileRob]

If you wanted to demonstrate the shear strength, why didn't you strike it on the side/edge to simulate the forces trying to push the "wall" over?

[@markw5805]

Rob Biedenharn I have to agree. I don’t think he tested it in the correct context to get the values he was saying. If he made a box and turned it like diamond and crushed it, then he would be measuring the crush resistance of the box form. This would be the correct context...right?

[@aayotechnology]

Exactly. He should have hit it at the corners and seen how the structure handled. He should also team up with a testing facility and make the show more "scientific". This would add to the show's credibility.

[@AgileRob]

Yes, that would have been better as a method to "demonstrate" shear strength. (I can't bring myself to use the word "test" since he's not really *measuring* anything.)

[@blueferral3414]

Here is my saying feel free to use it as said by the customer, "My anecdotal evidence trumps your years of study!"

[@doom4067]

Maybe he's worried about hurricane force winds from inside the house...

[@6stringsandapick]

It would be great to actually test the sheer strength.

[@kebin760]

Put it on its point then hit it downward with controlled weight. Nvm Ill reach out to project farm

[@roberttomsiii3728]

@@kebin760 👏👏👏🤣👍

[@timgarcia2264]

Absolutely meaningless video. Hitting it in the manner shown does not tell you if it adds to the shear value.

[@Threxx]

When you struck the foam directly in the final test, it actually reduced the force of impact in a way that normally wouldn't be a benefit of closed cell foam (direct strikes to the foam-covered area). The force of the impact (deceleration of your hammer) was spread out over a longer period of time, similar to how crumple zones in cars work. The difference in force between complete deceleration in, say, 0.01 seconds and 0.03 seconds, is huge.

[@larrykolden1047]

That does not test shear strength, pointless dumb test

[@chinnana583]

Exactly. Foam is acting like a shock absorber, decelerating the hammer considerably before it touches hard part. But anyways you reminded me of High school physics, where kids confused difference between Momentum vs Impulse... :)

[@adshwartz]

That is the wrong test... To test it you need to take a square wall and try to push the upper corner of one side and buttom corner of the other side, in the direction of the oposite side. Basicaly trying to force a square ahape into a diamond shape

[@joshn3042]

You failed on this video. You basically tested how well does the foam act as a glue/ what is it’s adhesion.

[@evandg13ify]

What I was thinking, thought the foam basically just added rack strength

[@theroboticscodedepot7736]

I agree with the other commentators - this is not a test of shear strength. You should nail the sheathing on as it would be on the house and then try to push the square over (i.e. make it into a rhombus). The way to do that would be to make a cradle to hold the square with two opposite corners pointing directly up and down then whack the top corner with the sledge hammer. That will act to force the square into a rhombus shape which is the same as a shear force would do.

[@ShaunWintheiser]

This is not a shear test???

[@johnpichette1146]

Build show has turned my sh"t show of a build into something amazing. I inherited a wreck of a home on the Delaware river. The house was trash, DE land use wouldn't allow me to replace it. COVID started preventing me from legally fighting them so we began to remodel. Products I've used from you show, zip, cavity slider, rock wool exterior, standing seam roof, fiberglass windows, fakro stairs, I had Corbit help with the HVAC plans. Mini split with ERV and continuous air recirculation ducting. This old river shack is probably better than a new home because of the materials used to rebuild it. Close in inspection is coming up and then closed cell foam everywhere. Conditioned attic space, foamed roof. Thank you for another Great show !!!

[@andrewjohnson9279]

The full spray absorbed some of the impact.

[@wjthehomebuilder]

I subscribed in the 75K range. What's nuts is that was only last July or August! This is really taking off! Good for you!

[@120ohm]

I really enjoy this channel and what your trying to do here! But I agree with the other comments, this is not testing sheer. Its better to have fewer well researched videos then many which are half backed. Keep up the good work.

[@akbmunsell]

Engineers will say that the closed cell foam adds sheer strength but I've seen no study that quantifies that strength in anyway, especially when it comes to actually reducing framing, whether that's headers, shear wall size and shape, or solid sheeting, etc. Plus, I've never seen an appraiser up the value/price of a house because of the added strength. Point being that it's still hard to justify using closed cell foam from a strictly money angle. That said, everything I build here in Alaska has closed cell foam in it because I think it's so much better that it's the right thing to do. Enjoy the videos

[@mrrepoo]

I’m trying to find videos now with seeing homes built up with this…

[@JerodMatlock]

Look up a Charpy Fracture Toughness testing machine - swings a hammer on a fixed hinge line at the end of the handle. Pull the hammer back to a known height then release. Measure the height of the follow-through swing, and you can understand the relative energy absorption of the three wall samples.

[@Trex450S]

In case any didn't point out the other obvious part of your test... The foam itself absorbed a lot of the kinetic energy of the blow. Oh and this was supposed to be a shear test not what you did. I know everyone picked up on that. But it was cool to see.

[@brucea3103]

How about building the same boxes, securing them to a base, then use a braced bottle jack on an upper corner to shift it out of square? You could count the number of strokes it would take to move the upper 2x4 say 3 inches. AvE would use compressed air with gauges.

[@buildshow]

great idea!

[@mulliganarch]

You need to take the impact absorption of the foam into effect. This test also seemed like more of a pressure vacuum test than a shear test as well. That all being said, love your videos; keep doing what your doing!

[@marshallkilgore8047]

Matt you are the best man! I'm not a construction or builder guy I'm a 26 year old salesman for vape products who is interested in building science and looking to build my own home next year. But I have been watching you for years and love your content so thank you to yourself and your sponsors and I hope nothing but the best for you! If you ever move to Ohio I will hire you haha

[@allenherinckx4474]

Have you put together a video on fixing mistakes after spray foam ie removal of the foam for wiring changes?

[@masausod]

I am disappoint. Please try to set up a test that has the sheathing properly attached to the studs, and then test the shear strength, not the blowout strength. When strong winds hit a house, the front surface that is perpendicular to the winds tries to fall over into the house, and this has to be resisted by the walls parallel to the wind direction. The force would be across your little square, not through it.

[@beebob1279]

I’ve seen you closed cell videos but never see wiring. Also what do you do if you want to add wiring or cable lines?

[@marks6663]

since everyone has already told you this is not a proper test, let me just say that the term for what you were suppose to test is Racking. When a frame is under side loading, the industry calls that racking. Houses under construction sometimes collapse from racking loads on a windy day if they are note properly temporarily braced.

[@RobotMowerTricks]

Well, that tested the impact absorption of foam 😜

[@adubbelde1]

My house is built with 2x6 studs, 5/8" plywood and 1" of exterior foam. 2 lb spray foam in the walls and rim. I also had them spray the interior walls that extended from a flat ceiling to a vaulted ceiling. Prior to spraying, drywall was installed. One bay was not screwed completely and the foam bulged it out. Getting that piece of drywall off and shaving the foam down was quite a feat. In my greenroom, there are 4 5'x6' windows and 2 3'x5' windows as well as a patio door. I sized my electric heat based on recommendations from a heating contractor, the energy provider, the Heating unit manufacturer and and electrical contractor. They surely don't understand the impact of the construction of the envelope as I'm WAY oversized on electric heat. In the entire house I only use 30% of the heating units and then only occasionally.

[@adubbelde1]

So much for proof reading, Not Green room but Great Room. I should ad that I'm in South Dakota

[@cairnsandy1]

glueing the exterior board to the studs , once that glue really sets up after a few weeks , the bond it makes is stronger than the bond between fibers within the 4"x2" , next question is how do you hold the roof on ???

[@mfkhometheater7742]

Question, does open cell add any strength? My foam guy screwed up and sprayed open cell where I wanted closed for added rigidity.

[@Threxx]

For a little more quantitative/scientific test, you might have tried facing those test setups up toward the ceiling and dropping a heavy spherical weight (like a bowling ball) from a fixed height onto each of them.

[@genedejoannis100]

Matt, I believe the shear force is the pressure that tends to rack the structural frame. This force is what is resisted by the sheathing panel by providing diagonal bracing. You tested the lateral strength of the panel attachment. Not the same. You would need to test by pushing (pounding) on one corner of the assembly and trying to deform it from its 90 degree corners to test shear strength.

[@user-tp2ks4ts2i]

Matt. A question on closed cell in timber frame. Does it allow the timber to breathe. I have a 2in. cavity in an existing house and im wondering should I use open or closed cell . My main purpose is to stop air movement and also structural. Thanks

[@157-40_T]

Matt, I’ve wanted to use 2” close cell in walls backed by Rockwool but I recall a video from a close cell installer that it was not a good idea. Is moisture the issue or something else? I think a hybrid approach may get better results that just closed cell but I am not expert. ???? Did you have any problems with the house insulation that arose???

[@caasinauj]

Hey Matt, I'd like to hear why do you hate post-tensioned slab foundations. Thanks

[@tomim7187]

How about anchoring the panels on the bottom only, then 2x on an angle, like a ramp, at one end inline with the frame. Then push it with a hydrolic jack braced on the ramp to see how long it would take to topple the wall. If you could put a gauge on the jack we could see what the psi is.

[@grendelum]

My new house is being built out of ~75 pieces (the factory takes the plans and turns it into large pieces) of a sandwich of concrete board on both sides with 8” of closed-cell foam in-between. The Herr(?) value (the overall insulation score that’s normally around 100-120) comes out to 45 as the floors and roof are also made with these panels and the windows are triple-glazed with a hurricane resistant layer... and yes, the houses built this way are up to Florida building code and survive hurricanes !!

[@edwardsmith7131]

Also: why rock wool instead of fiberglass? I assume that full thickness foam gets in the way of in-wall service installation (electrical, plumbing and the like) but what are the advantages of rock wool over fiberglass in a residential installation?

[@1forthepeople969]

@Matt: Really enjoyed your video & demonstration. Thank you for sharing.

[@rurikwilmot7676]

A more empirical test would have been to have the sledge hammer pinned to a hinge so that the swing force would be identical. Also, wouldn't this be more of a blunt force direct impact test vs. a sheer test?

[@sandiego22tnt]

Any recommendations for closed cell spray foam companies in Los Angeles area for making the attic a conditioned/unvented space?

[@audislowroad]

As others stated, this didn't test sheer at all and the primary reason that the third sample didn't immediately blow out is because of the shock absorbing cushion effect of the foam. The dented foam means energy was absorbed! I would setup the same boxes, nailed to standard, with a shop press and a large scale. Then perhaps make measurements on how much diagonal pressure in lbs each sample endures at specific diagonal deflection measurements (1/32", 1/16", 1/8", etc). Otherwise, I appreciate your videos and keep your houses tight!

[@derekrosecrans1361]

Cool test, closed cell is really pretty strong. I've had to cut into it before and make some changes to framing and it is a pain to try and get off. It would be interesting to see how much force you would need to apply to your three panels trying to get them to rack out of square. Think that would show indication of sheer strength. Thanks for the fun video.

[@jeffwiebe6913]

I thought you would put it in a Hydraulic press diagonally or something :) very cool though! 👍

[@MarkS-gw6qd]

Hey Matt, when you do closed cell like this on walls, do you or can you use a fluid applied barrier on the outside of sheathing? For ceilings, can you use fluid applied or the good peel and stick on the outside, or is that asking for moisture to be trapped? Really like the closed cell idea, just not sure what is safe to compliment it on the outside. I'm in Northeast Texas.

[@stephenhines2795]

How much would it cost to do a closed cell foam home of 2000 square-foot house or less

[@lolMyke]

Look into a recent incident in Niagara Falls Ontario. 3 new houses just blew over due to high winds.

[@christophergruenwald5054]

Closed cell foam also is great for uplifting strength on steel or any other substrate. As we are seeing here. Actually if you have a post frame building with steel on perlins in a hurricane zone or tornado alley, then this is by far the way to go. Any structure really.

[@eaglecot]

It should be easy enough to do a test clamping the frame over the diagonal. Check out Matthias Wandel pump jacks on scale

[@aayotechnology]

As much as I like Matt's videos I'm often thinking he's only coming up with these pseudo-science demos to sell whichever product, not to prove anything.

[@ACommenterOnYouTube]

aayotechnology: The more videos i watch of his, they all seem to appear that he really knows his stuff especially from ME not knowing much about building homes, i look at him and think, i should hire this guy to build my next home, but then i read all the comments in ALL the videos and 95% are negative .. They all attack him and tell him he is doing it wrong or missed out on all the points.. So me.. i would want to hire this guy to build the perfect home but then reading the comments im like... ahh maybe not lol

[@mdh.3421]

The best way I know to test sheer strength is to take the same three squares and screw just the bottom down really really good. Like a framed wall attached to a foundation. Then you take the sledgehammer and hit the 2x4 on the side but near the top not the bottom. That lateral force will test strength, and you want to hit the 2x4 not the facing board. Just my 2cents You make awesome videos thank you!

[@Ralphieisthegreatest]

I can't add anything to what's been said here already. I was looking for info on how it might work in holding vertical bracing in an aluminum boat.

[@express375]

conclusive,thanks

[@uncertainscientist]

The closed cell foam is absorbing the force of the sledgehammer and distributing it. Is this what you're intending to measure with shear strength? I was thinking you were going to hit it on an upper corner (like you're trying to force the square to a trapezoid). I'm not sure how how this test would give any indication of increasing the shear strength. Also, you could hang the hammer and just let it drop from a 90 degree angle to get a consistent impact force next time!

[@edwardsmith7131]

To test shear strength (idea #1) : (1) Use the same 3 test fixtures prepared in this video. Maybe a 4th one with just the 2x4's for fun. (2) Very securely anchor the bottom of each to a solid and very heavy base just as done in the video. But with more weight and more strength. (3) The direction of force applied in the test is along the long axis of the 2x4 opposite the ground attachment. This will attempt to SHEAR the square into a trapezoid. (4) force will be applied by a hand operated ratcheting winch (come-a-long). (4a) Attach a steel tow cable to something at least as sturdy as a heavy duty truck in the direction of pull. (4b) Attach cable to the OPPOSITE side of the 2x4 being pulled with a steel plate to spread the load of the cable in contact with the 2x4. If a lag bolt is used on the winch side you are adding the variable of lag bolt attachment strength. The cable cannot be allowed to damage the surface of the 2x4 or results are unreliable. (4c) If you have access to a heavy duty weight scale that can be attached between the winch and the frame sample under test you could get numerical results better than "wow that's stronger". (5) Apply torque to the test sample until strain is heard and slower until the sample stretches out of squareness. (6) Record results For Science!

[@mplogue]

As others have noted - this does not test it's sheer strength. To test this with your setup, you would want to compress the units corner to corner. This would better simulate a sheer stress load.

[@DrewBe59635]

Good example. BUuuuuutttt........ Shear is side movement and not blowout. It would be shown by hitting the top corner parallel to the plate in line with the plate. When the hit comes, it will change shape from a square to a parallelogram or come apart. Use just plain nails that only go into the studs and plate about an inch. IE. Design it weak, so the foam strength shines through. Just like you did with this test. You did a good job showing that a 2" foam fill does add strength to holding on the sheeting. You also showed how much the foam will back up the sheeting for protect from flying debris. Still great to see. Just wish the cost of foam wasn't so great.

[@he-man3653]

Aside from cost, are there really any downsides to using closed cell foam?

[@ZidaneSteiner]

what are the long term harmful health effects of spraying a chemical foam into our walls?

[@glen7463]

Try knocking in a nail with a metal hammer then do the same nail with a same weight rubber mallet the foam absorbed the impact but the foam will add some strength but not as much as the Osb not even close

[@yaosio]

In this you were testing the ability of the foam to act as an adhesive to hold the board in.

[@mcm95403]

Matt, I think the real test would have been force from the OUTSIDE, not the inside. A sledge hammer impacting with a repeatable swing so that the impact was the same each time. That would simulate a high-speed impact, but you would also need to do some sort of a frame test that shows how much the foam increases rigidity against a force equal to hurricane force winds.

[@brad3278]

Sure do see a bunch of negative comments, seemingly mad at this guy in the video. There's a difference between constructive criticism, and just simply hating on the guy. You don't have to watch...

[@layefarg8726]

Hey Matt, I'm an owner builder in northern California and I've been learning a lot from your videos. Thank you. Any in depth research into fire protection, our main danger here?

[@billyhigginbotham2746]

Humm so when does the sheer test start???

[@WillPittenger]

The impact test wasn't testing shear. Shear would be racking the frames. The shown test was basically the 2x4 impact test, but from the wrong side. You tested the impact from the inside whereas an actual impact would be from the outside. A retest is needed.

[@66block84]

Steel re-enforced concrete domes, in your state of Texas, Italy is the small town. Monolithic Domes. MUCH stronger and survive many of the impacts the other commenters are asking about. Including 9mm.

[@mrgylex123]

Unfortunately this isn't an effective test to show the supplement of shear strength vis a vis Closed cell. This is mainly showcasing the impact resistance from a small surface area. You can place any material to yield similar results as it would 'dampen the impact'. Shear forces are the unaligned vectors pushing a material in apposing directions. This is usually represented by the forces enacted laterally on wood like a framed wall. What would be interesting is the same test but with a linear actuator pushing on the frame until failure. Measure distance until frame failure as your metric to evaluate performance of closed cell vs X

[@jebert327]

Thank you

[@tommytsunami5147]

What u opinion on RAM Earth build houses

[@Sqtgdog]

Video description does not state this is a shear test, but in the video you say that. Unfortunately you didn't actually test shearing. Not trying to be a troll, but maybe you shouldn't be winded after swinging a sledge a couple times? Stay Healthy!

[@Jack-ny7kn]

The foam acted to decelerate the blunt force impact of the hammer. What you need to do is get a press and squish those frames. That would take blunt force out of the equation.

[@thordehr]

That's great, but I thought you were going to test for shear?

[@jonathanlanglois2742]

The one thing which I notice from your third test is that the foam actually dissipated a lot of the force of that blow.

[@virgil3241]

If I could turn back time, and build my own house, this would be awesome. I wonder if you get a break on home insurance if you can prove you did this, since it would stop a lot of claims

[@1new-man]

Matt that was neat. Point well taken indeed. One of those tornado shelter wind tunnel test would be interesting. on a 4x8 framed sheet/ Lol

[@patbullard9276]

Looks like a test that Project Farm would be able to test for a good finding.

[@lostsurveyor3036]

Cute, you dork! Great video. Thumbs up.

[@jimrumsey8077]

Let me know when you do a shear test never did see one

[@MatthewBallinger]

You explained sheer strength as a load trying to push the house over and even moved your hands in the direction of stress….and then did tests in a totally different direction. Can you explain this?

[@chiefinspector7280]

Shear is diagonal tension resolved into a couple of tension and compression components with drag struts connecting them. You hitting them with a hammer is only testing the shear capacity of the foam. The foam will add to the compressive capacity of the wall and shear by making the wall more rigid. Foam is unsafe.

[@doom4067]

If you have hurricane forces coming from inside the house, as this test indicates, you have big problems.

[@waltradcliffe4482]

I was going to say something similar like the sheeting is on the outside try turning it around

[@straight-up-shots]

Alan Wood Hahaha very good point!

[@leedstao]

This is not testing the shearing force. You are testing the strength of the nails. The reason the last one last one more blow is because the foam is absorbing the impact.

[@marcitecture]

Not sure the third sample was an accurate measure. Looks to me that you tested how much the foam cushioned the blow of the sledge hammer and reduced the impact force on the sheathing. The picture frame example was a better example because the sheathing was 'glued' to the studs, but the sledge was still able to make solid contact with the sheathing. To redo the third sample more accurately, try nailing a scrap piece of 2x4 at the middle of the sample and then hit that spot with the sledge hammer. I would bet that you will find the strength of the fully foamed sample to be similar to the picture framed one.

[@tophat2002]

Does it damper sound?

[@Goosie222222]

How about having it standing on a corner and hit the top corner?

[@JLHOLT91]

What engineer's are saying 75%-200%? I'd be interested in seeing that. I have a lot of homeowners that ask about it. A better way to test this in shear would be to attach the bottom plate as rigidly as possible and then apply a force to the top corner parallel to the face of the sheathing. All you are showing is the strength of the fasteners in pull out which is the weakest direction. It would be great to be able to show the documentation of how much strength it adds.

[@lancerudy9934]

You are swing as hard on third frame.?

[@helookalikaman79]

Why only spray part of the wall cavity? Fill it up!

[@phillipnunya6793]

The full fill did't come out the first time because the foam absorbed some of the impact. It's was't really a good test to measure the stress of the frame because you were whacking the panels dead center from the inside, which doesn't simulate the stress a storm would put on a house. That, and a sledge hammer doesn't distribute force like wind would. Still an interesting test, but I have to point out the flaws. A better (and more expensive) test would be to build a little box with hooks screwed into the frame at even intervals, connect all the hooks up to a separate little rope, and then pull on all of them at once. Still not a perfect test, but much more representative of actual storm winds. Most people wouldn't bother to go that far, but then again this is your profession so maybe you will.

[@mikemueting7344]

This test has nothing to do with shear forces from a hurricane. You tested the adhesive properties of the foam as well as the foams ability to absorb energy from impact. I've never seen a hurricane cause impact on foam insulation.

[@brettallenthomas]

Yes, the foam absorbed the impact of the hammer blow, which has nothing to do with sheer strength, or adding rigidity to the wall..

[@RecAmend]

The additional foam on #3 at the point of impact absorbs a lot of the energy from the impact from the HUSKY sledge.

[@guybarnett131]

Good to know, just wish I had that done before I put my sheetrock up and tape and floated.

[@Psychlist1972]

This was fun, but not really showing anything. I assume you were trying to just have fun anyway, since this didn't show anything about shear strength. The foam absorbed the impact on that third board. You likely would have had similar results if you whacked a batt of rock wool. I've used closed cell spray foam here. Definitely helps with rigidity with this horrid late 70's sheathing. Also helped with sealing this basement (cement block walls, so very open to the outside). Really great all-around with no real downsides that I've been able to see.

[@BillKristjanson]

So, when are you going to test shear?!?

[@ispacedesign]

Would rather see the racking between the samples. Do-over!

[@buildshow]

might do a second version

[@gregoriomurtagian5347]

I hope you realize that in test #3 you are impacting the foam and it is acting as a shock force attenuator so that's why the result is different from test #2. Both #2&3 should have the same 'shear' strength as you have the nails and the foam glue effect on the perimeter holding the board on the frame.

[@Ariccio123]

Next: how much closed cell does it take to stop a 9mm?

[@jchappell2120]

Hope nobody is standing behind that test 😂

[@buildshow]

Maybe Matt at Demolition Ranch can join me for that one!

[@doubledarefan]

Yes! 2 Matts together! Do it!

[@alucardlledroc]

How did that test for sheer strength i will never know

[@jr3474]

that was a test for the nails and the help from the foam.

[@williamlopez5462]

I stand with ICF, no need for expensive wood, expensive foam, and extra work, Wood comes from trees, and a Tornado has more force than a hurricane. ICF is the way to go

[@numetheus]

I don’t understand how this tests shear strength. By hitting the backing, you are just testing its properties as an adhesive to keep the backing on, and it’s ability to absorb impact. As you can see from the first hit, that sent absorbed the energy of the hammer. Sheer strength test would be if you put it sideways and smacked the wood frame from left to right. The one without the foam would collapse to the side. The one with the foam adds rigidity. Sort of like adding cross members.

[@Sqtgdog]

If your only purpose was to increase shear strength, would it be cheaper to just double up on 2x4s in all the walls rather than use the foam. I realize you used the foam for more than just shear strength, but most people are not building homes to survive hurricanes. Just trying to delve for some more economical ways to increase the structural strength without the time/cost of foam installation.