I just talked with a Morin Corp technical rep about attachment methods for the metal panels -- within the context of using some continuous insulation on the outside of the metal studs and sheathing to satisfy the IECC.
I've done this on other projects using furring channels and insulation between. Which, kind of wrecks the "continuous" part. And it's quite a bit more labor.
Anyway, the tech rep said that it's possible to skip using furring strips and instead use a 6" diameter "bearing plate" (metal or plastic) at each screw -- this plate prevents sucking the screw too far in and thus creating "waves". Of course, the screws must go all the way through to the studs. Yes, this does create small thermal bridges at each screw.
Anyone ever done the suggested method, or have any input?
wurdan freo
Feb 25, 14 12:14 pm
My interpretation is that the 6" plate holds the insulation in place. That sounds fine, but what do the panels attach to?
If you use a Z and insulation it will be more continuous (?). I've seen that alot. Then the panels attach to the Z.
Saint in the City
Feb 25, 14 12:19 pm
wurdan -- the insulation is assumed already attached. What was suggested to me is that a "6 dia bearing plate" is behind each screw that attaches the panels -- that way you can create enough friction to hold the panel in place without crushing the insulation. The panel attachment screws go all the way through the insulation / sheathing to the metal studs.
Obvioulsy, the thicker the insulatin, the less well this probably works....
The Z's or channels is what's done a lot, and I've done that as well -- looking for simpler, less parts and labor -- and also more 'continuous' as far as the insulation goes.
curtkram
Feb 25, 14 12:26 pm
sounds like roofing nails. since the metal and insulation are squishy, you need the can lid to prevent the screw from poking into the panel too much. 6" seems like a lot to me though. you can get insulated metal panes (since the insulation is already built in). it seems that might be easier for what you're trying to achieve. something like centria.
you still have sheathing when you do that right? so, stud -> plywood or densglass -> foam -> finish surface? you could get around the can lids and double the cost by going stud -> sheathing -> foam -> more sheathing -> metal panel. they make roofing panels with integrated cover boards, which might be enough to nail the metal to, so your insulation and second layer of sheathing would be integral. i've never heard of that in a vertical application though. just tossing out thoughts. no idea if it would be practical.
wurdan freo
Feb 25, 14 12:28 pm
Finding the studs could be a pain if the insulation and the panels are done by two different companies. Bigger concern would be sagging of the panels and worst case scenario the screws pulling out of the studs after sagging. Did he say anything about that?
Saint in the City
Feb 25, 14 12:37 pm
^Wurdan -- indirectly -- he's looking for the 6" dia to generate a friction connection, so that theoretcially the screws won't pull out -- as I get further into it I'll find out if what he's suggesting actually satisfies warranty requirements or if he was spitballing. You'd think if he was suggesting it, it would, but I've learned a long time ago that you can't rely on without something in writing.
wurdan freo
Feb 25, 14 12:59 pm
Does his company install the panels or are they just a manufacturer? The manufacturer warranty is important, but I would also make sure I'm talking to someone who could actually do the installation.
mightyaa
Feb 25, 14 1:35 pm
Code violation. Attachments are to be to 'solid blocking'. Rigid insulation is not to be utilized structurally or used to support loads (it tends to allow the screw to tear through it). So you'd need to 'engineer' the attachments since the loads are at one end, and the stud is some distance away and you can't rely on the insulation to provide any support. Shear and deflection become an issue on the fastener itself.
Oh, and don't forget to properly size the attachment length. A very common defect I see is standard fasteners/staples on exterior gypsum sheathing walls. Gypsum is the same way: it can not be used structurally like that, so the fasteners need to go past it and get the minimum embedment into the studs beyond.
curtkram
Feb 25, 14 2:35 pm
if you had an extra layer of sheathing on the outside of the insulation, wouldn't that help reduce shear and deflection for the fastener? i suppose the fastener might get a 1/2 or 3/4" longer, so that might make it worse.
i was thinking cover boards because they're bonded to the insulation rather that mechanically attached. obviously they're meant for horizontal rather than vertical applications, so you'd either need to do a pull test to make sure the outside works the same as plywood or get a better material. i agree that one should not attach directly to insulation or use insulation structurally. the fasteners would have to go through the other side of the wall.
1045.11 suggests that it should be ok to attach metal veneers to 'approved sheathing.'
an insulated metal panel made to what he's asking for would probably be easier. here is a picture where they attach a rain-screen metal panel on top of their insulated metal panel:
Saint in the City
Feb 25, 14 3:15 pm
Mightaa -- Such a system doesn't necessarily result in a code violation -- maybe I'm not clear what I'm looking for. Foam is weak in many types of loadings, but it's used all the time under compressive loadings, and is psi rated accordingly. Each siding application will be different, but the weight of metal panels can be less than one pound per SF. The "can lids" were simply the tech reps way of effectively using the foam sandiwched in compression.
Since I first posted, I've looked a little deeper --Themaxx (Dow) looks like a version of what I'm looking for. Maybe this will help:
This actually show a fiber cement siding, but other materials are shown elswhere on the site.
Need to study this a bit more.
gruen
Feb 25, 14 7:21 pm
Saint, this has been a huge problem for me too. Foam w a plate is a common detail for standing seam roof. The screws aren't much of a thermal issue as the z strip. The metal panel people have no decent detail because they want to sell more expensive insulated metal panels. I say go for it. I don't think panel sag will be an issue, but if you are worried, just do the math on the gravity loss on each screw.
mightyaa
Feb 25, 14 7:50 pm
Just notice they cover their butt by referring to stainless fasteners "verify with structural details" The fastener must be engineered to support the finish without relying on the insulation for support. So if you use 3" insulation, that fastener needs to be engineered to hold the finish 3" away from the structural supporting elements.
It does have compressive loading capability (crush resistance). I also noticed dow has a pvc clip channel. That might have structural capability without the thermal transfer. Might be your ticket. A double wall can also work; Balloon frame the shell using clips to attach to the steel frame and separate the interior partitions.
Oh, and also be specific about the length of fastener. It needs to penetrate into the framing a specific depth to grip. I see that one screwed up all the time at least on wood framing and stucco. Like a 3/4" or 1" staple on the lath.. Um... they have 5/8" gypsum (same non-structural sheathing issue), and the lath is at least 1/8". That's 3/4" to the stud. 1/4" embedment won't hold assuming they even hit a stud (which also typically doesn't happen when you combine yahoo with a airgun). I've seen cultured stone and stucco peel off of facades due to this.
Another hint just in-case this is residential. Be very careful of thermal bridges. Residential doesn't use outside air on the HVAC (which is usually mixer box using the hot water heater). When sealed up tight, I've seen humidity levels grow when occupied to condensate at those bridges creating big issues. This is a code issue in my opinion, but one to watch for.
jyount10
Feb 25, 14 8:48 pm
Look at the Dow Knight Wall system (not Thermax). First system I've seen that truly takes the CI requirement to heart.
Saint in the City
Feb 25, 14 9:01 pm
^ Actually, Dow Knight uses Dow Thermax insulation / sheathing. But you're right, it's an interesting system.
Saint in the City
Feb 25, 14 9:31 pm
'Just notice they cover their butt by referring to stainless fasteners "verify with structural details" '
Nah -- the note references necessary coordination with building structure -- the fasteners you need are elsewhere on the website.
Saint in the City
Feb 26, 14 11:04 am
Gruen -- the c.i. saga continues... I've looked into this Thermax thing a bit more since posting. I'm guessing there are other comparable brands/systems, but if you have a minute, the Dow website has some interesting videos,etc, -- jyount10 is correct, too -- take a look at the Dow Knight system. Let me know what you think.
Miles Jaffe
Feb 26, 14 11:12 am
All the more reason to design a structural / load-bearing skin and insulate the wall cavity. Also lots of exterior insulation systems have dew point problems causing rot and mold (STO, Dryvit, etc.). Or in this case rust and mold.
Saint in the City
Feb 26, 14 11:43 am
^ Not always an option. The c.i. is required to meet the IECC -- at least prescriptively, which is required in many jurisdictions.
Miles Jaffe
Feb 26, 14 12:07 pm
We've got some bad codes here, too.
gruen
Feb 26, 14 8:27 pm
I'm curious about the Dow knight. But is it affordable?
Saint in the City
Feb 26, 14 9:10 pm
^ not sure about the Dow Knight -- I may get some pricing just for reference.
As far as the Thermax price goes -- it appears to run in the $50 / 4' x 8' x1.55" size.
1.55" / nominal 1.5" = R9.8.
The product becomes your sheathing (non-structural), your drainage plane, and your vapor barrier. If it works, that's pretty cool.
I'm considering it on my current project -- steel frame with some x-bracing so no need for structural sheathing. So the Thermax insulation directly applied to the studs -- no ply or Dens or OSB.
gruen
Feb 27, 14 5:27 pm
Interesting. I'd love to see the details-especially top and bottom of the wall & at windows/ doors.
Saint in the City
Feb 27, 14 5:53 pm
Well you and me both -- I'm trying to get with the company for some real-world case study examples and details. I'll keep you posted.
TedTedTed
Feb 27, 14 6:39 pm
When talking with a rep recently about trying to use Rieder/Oko Skin for a portion of a rainscreen facade, he brought this product up to me as a suggestion to help with the thermal bridging associated with secondary framing members. Looks like it might be useful...
Just thought I would bring it up as a possible option for the original issue in the post. Also, since you all were discussing R-values before polyisocyanurate is now only listed at 5.6/in as of the beginning of this year due to new testing. Just a heads-up when figuring your continuous on the exterior of the wall.
LauraSteele
Mar 12, 14 4:16 am
Saint in the City- great thread. I'm working on a residence in upstate NY with a large area of glass on the facade and super insulated walls (4" CI on outside face of stud). As someone who mainly works in California this feels like a very puffy coat.
We also have a post and beam system with cable bracing so the walls are just partitions holding themselves up. Hoping to avoid any sheathing at all. Walls will be steel studs, 4" rigid poly iso built up in two 2" layers with staggered joints/dow weathermate tape, considering using griplok fasteners to attach the insulation. Then we'll need strapping at 2' o.c. (likely a 1x3 nailer) and the fiber cement panels will be added to this either with long screws
Or big question is how to fix the concrete fiber cement panels. Client wants to use a simple hardie panel because its the cheapest panel out there in white, but this detail will void the warranty. Does anyone know a panel maker that has installation details for 4" or more of CI? And, does it come in white?! We typically use minerit HD - a decent quality, mid-grade panel that requires a simple clear sealant, but the client hates the color. Etercolor and fibre c are too expensive.
I found this interesting report on cladding over CI - looks like the beginnings of new code language for these details:
sizzle -- interesting. I'm also working on a house project with continuous insulation, and have been looking at hardie board / Nichiha type products. However, I'm looking at 2" continuous -- not 4". The comination of what you're attempting sounds difficult -- I'd first think maybe a product like what TEDTEDTED posted would help, but with no sheathing the CI would be tough to attach since the Cascadia Clips go over the studs -- the 4" CI panels would have to be cut to fit between the clips...so then how to attach in a void space?... sounds a little loosey goosey . Can you add conventional sheathing? The studs + sheathing + clips and rigid insulation appears to perform very well if the literature is accurate.
We make a composite Z Girt that eliminates all thermal bridging, even in the fasteners. You can use a rigid board (we profile polyiso), and create an air, water, vapor, and thermal barrier in a single continuous layer.
My email is [email protected] if you are interested in learning more. It is simple, effective, and cost effective.
gruen
Apr 30, 14 8:29 pm
Great product idea, I've seen similar before. What insulation depths will it take and what about air gap for rain screen? What is the cost compared to metal z girt? Is it tested? Fire resistant? Fire rated assemblies?
GreenGirt
May 2, 14 12:37 pm
The new Simple Z goes 2"-4" in half inch increments. That being said, 3" of polyiso continuously applied without thermal bridges will give you compliance to nearly all ASHRAE codes.
Air Gap for Rain Screen Once we break the thermal bridge, you could apply a small hat girt to the exterior of our girts on the right centers and orientations to accommodate your cladding. Or, we can give a girt that is deeper than the insulation panel or spray foam that we apply in the girt. This will give you the air space you need.
Based on a single air, water, and vapor barrier system versus our new GreenGirt, we are cheaper. This comes from a comparable cost for the full bill of materials, but a labor factor that is nearly 5 times better. Check out this YouTube video to see how fast the system goes up. https://www.youtube.com/watch?v=3PdqTwDvoOk
GreenGirt has gone through AAMA 501.1-05, ASTM 283-04, 331-00, 330-02, WUFI modeling for ASHRAE 160, Thermal testing for ASHRAE 90.1 2013, and hundreds of other tests including pullout tests, and durability tests.
When added to a high quality dual foil PolyIso panel 3" or less, over open studs, we are NFPA 285 compliant with any cladding. 4" works and is tested if you are on CMU.
Please reach out if I can give you any more information. Please check out our site at www.smartcisystems.com, you have my email, and take a look at our youtube video. Let me know if we can help with your project.
jaycool
Dec 29, 20 2:46 pm
Saint.
Have a similar situation. I'm using a single layer of 4" polyiso Foam board over 6" metal studs vertical 24" on center. Made 4"X4" angle brackets to apply to hard side of studs seperated by a layer of roofing membrane (to create a thermal brake) layout for angle brackets 24" on center. Using spray adhesive to hold foam boards vertically to face of studs and angle (temporarily). Install boards on entire area then install vapor barrier/ moisture barrier. Mark angle bracket layout horizontally on surface of v b and with 5" screws secure both outside edges of DWC / Hat Channel through foam board to angle brackets which holds everything in place with no outside screws directly through metal studs. I did seal the foam board joints with tape before vapor barrier was applied. Same application used on the roof. Sealing all voids between rafters and top of walls to complete the C I The hat channel horizontal layout will accommodate metal R panels for exterior cladding. I tested a mockup version by applying pressure against the DWC by pushing from the inside along with pulling from the outside without movement. With an R value of 22 + I'll use R 19 fiberglass insulation in stud cavity and sealed Continuous Insulation I'm pretty sure ERS / HRS will help maintain consistent fresh air and dehumidifier will eliminate any condensation that may be lurking. 4 zone mini-split unit just in case I need extra warm or cool air along the way.
Used small rubber washers on ALL screws to reduce thermal bridging as well.
apscoradiales
Dec 29, 20 3:57 pm
To the OP or anyone else; don't try to design your own wall. There are a whole plethora of issues with any wall, including insulated metal ones...thermal bridging, wind resistance, seismic implications, structural integrity, moisture resistance, vapour resistance, colour steadfastness, corrosion...
The wheel has already been invented - use a proven, and tested system by VicWest or Berridge or anyone else out there.
apscoradiales
Dec 29, 20 4:11 pm
Forgot to mention, in case of any problems you can't point the finger at anyone - they will all say, "it's the other guy".
I just talked with a Morin Corp technical rep about attachment methods for the metal panels -- within the context of using some continuous insulation on the outside of the metal studs and sheathing to satisfy the IECC.
I've done this on other projects using furring channels and insulation between. Which, kind of wrecks the "continuous" part. And it's quite a bit more labor.
Anyway, the tech rep said that it's possible to skip using furring strips and instead use a 6" diameter "bearing plate" (metal or plastic) at each screw -- this plate prevents sucking the screw too far in and thus creating "waves". Of course, the screws must go all the way through to the studs. Yes, this does create small thermal bridges at each screw.
Anyone ever done the suggested method, or have any input?
My interpretation is that the 6" plate holds the insulation in place. That sounds fine, but what do the panels attach to?
If you use a Z and insulation it will be more continuous (?). I've seen that alot. Then the panels attach to the Z.
wurdan -- the insulation is assumed already attached. What was suggested to me is that a "6 dia bearing plate" is behind each screw that attaches the panels -- that way you can create enough friction to hold the panel in place without crushing the insulation. The panel attachment screws go all the way through the insulation / sheathing to the metal studs.
Obvioulsy, the thicker the insulatin, the less well this probably works....
The Z's or channels is what's done a lot, and I've done that as well -- looking for simpler, less parts and labor -- and also more 'continuous' as far as the insulation goes.
sounds like roofing nails. since the metal and insulation are squishy, you need the can lid to prevent the screw from poking into the panel too much. 6" seems like a lot to me though. you can get insulated metal panes (since the insulation is already built in). it seems that might be easier for what you're trying to achieve. something like centria.
you still have sheathing when you do that right? so, stud -> plywood or densglass -> foam -> finish surface? you could get around the can lids and double the cost by going stud -> sheathing -> foam -> more sheathing -> metal panel. they make roofing panels with integrated cover boards, which might be enough to nail the metal to, so your insulation and second layer of sheathing would be integral. i've never heard of that in a vertical application though. just tossing out thoughts. no idea if it would be practical.
Finding the studs could be a pain if the insulation and the panels are done by two different companies. Bigger concern would be sagging of the panels and worst case scenario the screws pulling out of the studs after sagging. Did he say anything about that?
^Wurdan -- indirectly -- he's looking for the 6" dia to generate a friction connection, so that theoretcially the screws won't pull out -- as I get further into it I'll find out if what he's suggesting actually satisfies warranty requirements or if he was spitballing. You'd think if he was suggesting it, it would, but I've learned a long time ago that you can't rely on without something in writing.
Does his company install the panels or are they just a manufacturer? The manufacturer warranty is important, but I would also make sure I'm talking to someone who could actually do the installation.
Code violation. Attachments are to be to 'solid blocking'. Rigid insulation is not to be utilized structurally or used to support loads (it tends to allow the screw to tear through it). So you'd need to 'engineer' the attachments since the loads are at one end, and the stud is some distance away and you can't rely on the insulation to provide any support. Shear and deflection become an issue on the fastener itself.
Oh, and don't forget to properly size the attachment length. A very common defect I see is standard fasteners/staples on exterior gypsum sheathing walls. Gypsum is the same way: it can not be used structurally like that, so the fasteners need to go past it and get the minimum embedment into the studs beyond.
if you had an extra layer of sheathing on the outside of the insulation, wouldn't that help reduce shear and deflection for the fastener? i suppose the fastener might get a 1/2 or 3/4" longer, so that might make it worse.
i was thinking cover boards because they're bonded to the insulation rather that mechanically attached. obviously they're meant for horizontal rather than vertical applications, so you'd either need to do a pull test to make sure the outside works the same as plywood or get a better material. i agree that one should not attach directly to insulation or use insulation structurally. the fasteners would have to go through the other side of the wall.
1045.11 suggests that it should be ok to attach metal veneers to 'approved sheathing.'
an insulated metal panel made to what he's asking for would probably be easier. here is a picture where they attach a rain-screen metal panel on top of their insulated metal panel:
Mightaa -- Such a system doesn't necessarily result in a code violation -- maybe I'm not clear what I'm looking for. Foam is weak in many types of loadings, but it's used all the time under compressive loadings, and is psi rated accordingly. Each siding application will be different, but the weight of metal panels can be less than one pound per SF. The "can lids" were simply the tech reps way of effectively using the foam sandiwched in compression.
Since I first posted, I've looked a little deeper --Themaxx (Dow) looks like a version of what I'm looking for. Maybe this will help:
http://building.dow.com/na/en/thermaxtws/images/pdf/Hardboard-Siding-Joint.pdf
This actually show a fiber cement siding, but other materials are shown elswhere on the site.
Need to study this a bit more.
Saint, this has been a huge problem for me too. Foam w a plate is a common detail for standing seam roof. The screws aren't much of a thermal issue as the z strip. The metal panel people have no decent detail because they want to sell more expensive insulated metal panels. I say go for it. I don't think panel sag will be an issue, but if you are worried, just do the math on the gravity loss on each screw.
Just notice they cover their butt by referring to stainless fasteners "verify with structural details" The fastener must be engineered to support the finish without relying on the insulation for support. So if you use 3" insulation, that fastener needs to be engineered to hold the finish 3" away from the structural supporting elements.
It does have compressive loading capability (crush resistance). I also noticed dow has a pvc clip channel. That might have structural capability without the thermal transfer. Might be your ticket. A double wall can also work; Balloon frame the shell using clips to attach to the steel frame and separate the interior partitions.
Oh, and also be specific about the length of fastener. It needs to penetrate into the framing a specific depth to grip. I see that one screwed up all the time at least on wood framing and stucco. Like a 3/4" or 1" staple on the lath.. Um... they have 5/8" gypsum (same non-structural sheathing issue), and the lath is at least 1/8". That's 3/4" to the stud. 1/4" embedment won't hold assuming they even hit a stud (which also typically doesn't happen when you combine yahoo with a airgun). I've seen cultured stone and stucco peel off of facades due to this.
Another hint just in-case this is residential. Be very careful of thermal bridges. Residential doesn't use outside air on the HVAC (which is usually mixer box using the hot water heater). When sealed up tight, I've seen humidity levels grow when occupied to condensate at those bridges creating big issues. This is a code issue in my opinion, but one to watch for.
Look at the Dow Knight Wall system (not Thermax). First system I've seen that truly takes the CI requirement to heart.
^ Actually, Dow Knight uses Dow Thermax insulation / sheathing. But you're right, it's an interesting system.
'Just notice they cover their butt by referring to stainless fasteners "verify with structural details" '
Nah -- the note references necessary coordination with building structure -- the fasteners you need are elsewhere on the website.
Gruen -- the c.i. saga continues... I've looked into this Thermax thing a bit more since posting. I'm guessing there are other comparable brands/systems, but if you have a minute, the Dow website has some interesting videos,etc, -- jyount10 is correct, too -- take a look at the Dow Knight system. Let me know what you think.
All the more reason to design a structural / load-bearing skin and insulate the wall cavity. Also lots of exterior insulation systems have dew point problems causing rot and mold (STO, Dryvit, etc.). Or in this case rust and mold.
^ Not always an option. The c.i. is required to meet the IECC -- at least prescriptively, which is required in many jurisdictions.
We've got some bad codes here, too.
I'm curious about the Dow knight. But is it affordable?
^ not sure about the Dow Knight -- I may get some pricing just for reference.
As far as the Thermax price goes -- it appears to run in the $50 / 4' x 8' x1.55" size.
1.55" / nominal 1.5" = R9.8.
The product becomes your sheathing (non-structural), your drainage plane, and your vapor barrier. If it works, that's pretty cool.
I'm considering it on my current project -- steel frame with some x-bracing so no need for structural sheathing. So the Thermax insulation directly applied to the studs -- no ply or Dens or OSB.
Interesting. I'd love to see the details-especially top and bottom of the wall & at windows/ doors.
Well you and me both -- I'm trying to get with the company for some real-world case study examples and details. I'll keep you posted.
When talking with a rep recently about trying to use Rieder/Oko Skin for a portion of a rainscreen facade, he brought this product up to me as a suggestion to help with the thermal bridging associated with secondary framing members. Looks like it might be useful...
http://www.cascadiawindows.com/database/files/library/CASCADIA_CLIP_user_guide___Nov2012.pdf
Just thought I would bring it up as a possible option for the original issue in the post. Also, since you all were discussing R-values before polyisocyanurate is now only listed at 5.6/in as of the beginning of this year due to new testing. Just a heads-up when figuring your continuous on the exterior of the wall.
Saint in the City- great thread. I'm working on a residence in upstate NY with a large area of glass on the facade and super insulated walls (4" CI on outside face of stud). As someone who mainly works in California this feels like a very puffy coat.
We also have a post and beam system with cable bracing so the walls are just partitions holding themselves up. Hoping to avoid any sheathing at all. Walls will be steel studs, 4" rigid poly iso built up in two 2" layers with staggered joints/dow weathermate tape, considering using griplok fasteners to attach the insulation. Then we'll need strapping at 2' o.c. (likely a 1x3 nailer) and the fiber cement panels will be added to this either with long screws
Or big question is how to fix the concrete fiber cement panels. Client wants to use a simple hardie panel because its the cheapest panel out there in white, but this detail will void the warranty. Does anyone know a panel maker that has installation details for 4" or more of CI? And, does it come in white?! We typically use minerit HD - a decent quality, mid-grade panel that requires a simple clear sealant, but the client hates the color. Etercolor and fibre c are too expensive.
I found this interesting report on cladding over CI - looks like the beginnings of new code language for these details:
file:///C:/Users/LSS/Dropbox/IT/1227%20Spiess%20itHouse/VENDORS/HERRINGTONS/Cladding%20over%20continuous%20foam%20insulation.pdf
As well as this engineering evaluation report on a certain long screw type (TRUFAST SIP)
http://nationalgypsum.com/ng/file/Trufast.pdf
TedTedTEd -- nice product.
sizzle -- interesting. I'm also working on a house project with continuous insulation, and have been looking at hardie board / Nichiha type products. However, I'm looking at 2" continuous -- not 4". The comination of what you're attempting sounds difficult -- I'd first think maybe a product like what TEDTEDTED posted would help, but with no sheathing the CI would be tough to attach since the Cascadia Clips go over the studs -- the 4" CI panels would have to be cut to fit between the clips...so then how to attach in a void space?... sounds a little loosey goosey . Can you add conventional sheathing? The studs + sheathing + clips and rigid insulation appears to perform very well if the literature is accurate.
I bet your window details are going to be fun.
Hey all. I have your solution to the beginning of this thread. www.smartcisystems.com
We make a composite Z Girt that eliminates all thermal bridging, even in the fasteners. You can use a rigid board (we profile polyiso), and create an air, water, vapor, and thermal barrier in a single continuous layer.
My email is [email protected] if you are interested in learning more. It is simple, effective, and cost effective.
Great product idea, I've seen similar before. What insulation depths will it take and what about air gap for rain screen? What is the cost compared to metal z girt? Is it tested? Fire resistant? Fire rated assemblies?
The new Simple Z goes 2"-4" in half inch increments. That being said, 3" of polyiso continuously applied without thermal bridges will give you compliance to nearly all ASHRAE codes.
Air Gap for Rain Screen
Once we break the thermal bridge, you could apply a small hat girt to the exterior of our girts on the right centers and orientations to accommodate your cladding. Or, we can give a girt that is deeper than the insulation panel or spray foam that we apply in the girt. This will give you the air space you need.
Based on a single air, water, and vapor barrier system versus our new GreenGirt, we are cheaper. This comes from a comparable cost for the full bill of materials, but a labor factor that is nearly 5 times better. Check out this YouTube video to see how fast the system goes up. https://www.youtube.com/watch?v=3PdqTwDvoOk
GreenGirt has gone through AAMA 501.1-05, ASTM 283-04, 331-00, 330-02, WUFI modeling for ASHRAE 160, Thermal testing for ASHRAE 90.1 2013, and hundreds of other tests including pullout tests, and durability tests.
When added to a high quality dual foil PolyIso panel 3" or less, over open studs, we are NFPA 285 compliant with any cladding. 4" works and is tested if you are on CMU.
Please reach out if I can give you any more information. Please check out our site at www.smartcisystems.com, you have my email, and take a look at our youtube video. Let me know if we can help with your project.
Saint.
Have a similar situation. I'm using a single layer of 4" polyiso Foam board over 6" metal studs vertical 24" on center. Made 4"X4" angle brackets to apply to hard side of studs seperated by a layer of roofing membrane (to create a thermal brake) layout for angle brackets 24" on center. Using spray adhesive to hold foam boards vertically to face of studs and angle (temporarily). Install boards on entire area then install vapor barrier/ moisture barrier. Mark angle bracket layout horizontally on surface of v b and with 5" screws secure both outside edges of DWC / Hat Channel through foam board to angle brackets which holds everything in place with no outside screws directly through metal studs. I did seal the foam board joints with tape before vapor barrier was applied. Same application used on the roof. Sealing all voids between rafters and top of walls to complete the C I The hat channel horizontal layout will accommodate metal R panels for exterior cladding. I tested a mockup version by applying pressure against the DWC by pushing from the inside along with pulling from the outside without movement. With an R value of 22 + I'll use R 19 fiberglass insulation in stud cavity and sealed Continuous Insulation I'm pretty sure ERS / HRS will help maintain consistent fresh air and dehumidifier will eliminate any condensation that may be lurking. 4 zone mini-split unit just in case I need extra warm or cool air along the way.
Used small rubber washers on ALL screws to reduce thermal bridging as well.
To the OP or anyone else; don't try to design your own wall. There are a whole plethora of issues with any wall, including insulated metal ones...thermal bridging, wind resistance, seismic implications, structural integrity, moisture resistance, vapour resistance, colour steadfastness, corrosion...
The wheel has already been invented - use a proven, and tested system by VicWest or Berridge or anyone else out there.
Forgot to mention, in case of any problems you can't point the finger at anyone - they will all say, "it's the other guy".