Hello experts, we're looking at using a Kodiak Steel Homes load-bearing red-iron frame system with their non-load-bearing steel studs and going with steel skinned SIPs for the walls and roof to eliminate thermal bridging from the steel frame.

Aside from the ultra-modern look, is this something that you think will work? My thinking is that, since Kodiak's system is a modified commercial red iron frame, SIP wall systems like Kingspan's were originally designed to work with this frame. However, history has shown that I am often wrong. We're in an earthquake-prone, high-wind (120-150MPH gusts), high-moisture area with salt fog, armies of termites, mold, and wood-loving critters. Besides that, it can be pretty nice :)

While it may be overkill (the SIPs will essentially just be exterior insulated panels attached to non-load-bearing Galvalume painted steel studs), are there any other issues you experts can think of? Including any long-term issues like corrosion, thermal expansion, SIP creep, etc? Our plan was to spray the red-iron frame with a marine-grade finish before attaching the SIPs.

Is there a way to utilize the strength of the SIPs to make the finished Kodiak house even more sturdy?

For windows and doors, I've seen people cut metal SIPs on site, but I'm guessing the best practice to send the building plans to the manufacturer for in-factory SIP cutting?

In terms of the roof, the idea was to utilize the new SolarCity glass solar roof tiles (not the traditional solar panels) for the outer roofing material over R60 SIP panels used for insulation, but with so little installation information out there, I'm not sure if we can use it on top of SIP roof panels for insulation. If you have any ideas on that, I would really appreciate it.

I've also seen wildly varying numbers in terms of steel SIPs pricing, even from the same manufacturer. A very informative and helpful post from Torben says he got Kingspan SIPs in Florida for under $3/sf:

"I have started building my home out of Kingspan panels. I'm using 6-inch panels (R-49) on my roof and east/west walls. I'm using 4-inch panels (R-33) on my north/south walls, which are well shaded (8-foot roof overhangs with balconies). I ended up paying $2.50-$3 per square foot for the panels (~$200 for delivery) and installation right now is costing around 25-50 cents per square foot." -Torben

This was from several years ago; Is $3/square foot for steel SIPs possible these days, even at the 4-inch thickness? Unfortunately, I'm not sure what finish the panels he used was.

Thanks for your time and advice.

Posted By greenbuilds on 27 Mar 2017 03:52 AM
Hello experts, we're looking at using a Kodiak Steel Homes load-bearing red-iron frame system with their non-load-bearing steel studs and going with steel skinned SIPs for the walls and roof to eliminate thermal bridging from the steel frame.

Aside from the ultra-modern look, is this something that you think will work? My thinking is that, since Kodiak's system is a modified commercial red iron frame, SIP wall systems like Kingspan's were originally designed to work with this frame. However, history has shown that I am often wrong. We're in an earthquake-prone, high-wind (120-150MPH gusts), high-moisture area with salt fog, armies of termites, mold, and wood-loving critters. Besides that, it can be pretty nice :)

While it may be overkill (the SIPs will essentially just be exterior insulated panels attached to non-load-bearing Galvalume painted steel studs), are there any other issues you experts can think of? Including any long-term issues like corrosion, thermal expansion, SIP creep, etc? Our plan was to spray the red-iron frame with a marine-grade finish before attaching the SIPs.

Is there a way to utilize the strength of the SIPs to make the finished Kodiak house even more sturdy?

For windows and doors, I've seen people cut metal SIPs on site, but I'm guessing the best practice to send the building plans to the manufacturer for in-factory SIP cutting?

In terms of the roof, the idea was to utilize the new SolarCity glass solar roof tiles (not the traditional solar panels) for the outer roofing material over R60 SIP panels used for insulation, but with so little installation information out there, I'm not sure if we can use it on top of SIP roof panels for insulation. If you have any ideas on that, I would really appreciate it.

I've also seen wildly varying numbers in terms of steel SIPs pricing, even from the same manufacturer. A very informative and helpful post from Torben says he got Kingspan SIPs in Florida for under $3/sf:

"I have started building my home out of Kingspan panels. I'm using 6-inch panels (R-49) on my roof and east/west walls. I'm using 4-inch panels (R-33) on my north/south walls, which are well shaded (8-foot roof overhangs with balconies). I ended up paying $2.50-$3 per square foot for the panels (~$200 for delivery) and installation right now is costing around 25-50 cents per square foot." -Torben

This was from several years ago; Is $3/square foot for steel SIPs possible these days, even at the 4-inch thickness? Unfortunately, I'm not sure what finish the panels he used was.

Thanks for your time and advice.

Greenbuilds, sounds like you have deeppockets,
steel skin SIPs alone won't eliminate thermal bridging, you will need to do thermal cuts to the skins as well

having installed precut and cut on site panels, I choose the latter, if the factory makes just one mis-cut it will throw you backs several weeks waiting for a replacement and depending on where the mistake is you may need to totally stop until the replacement arrives

There are panel systems that are structural without a frame that are both Hurricane and Earthquake resistant

Torben's build was several years ago and Kingspan's pricing is much higher, they do not precut.
subcontracted Installation is at least $2.00 sq. foot and up depending on complexities

What Torben didn't talk about was he had to buy twice , the first time was on the secondary market "seconds" they were literally falling apart, so if you factor that in to "total cost" it was probably $5.00 to $6.00 sq. ft., please don't fall down that rabbit hole

Thanks for your thoughts, Chris.

The Kodiak red iron frame is only $16,402 for a cottage, or $25/square foot. Everything is factory cut and bolt-together.

It seems like a good system, but I have read complaints about insulation and thermal bridging. By using steel SIPs, I'm basically making an "everyperson's EcoSteel" setup. EcoSteel estimated to me $125/square foot for an unassembled frame, SIP panels, roof, windows, and doors, but this will vary widely based on your project. In the years past, I've been quoted $70/sf from EcoSteel; either number is up there for a shell.

The glass solar roof tiles were claimed to cost "the same as a regular roof minus the cost of electricity". It's hard to verify those claims until they have some numbers out, but it's on the list of considerations.

Cutting metal SIPs on-site did seem to be more flexible. I was wondering how the factory cut SIPs would deal with any variations or tolerance issues that inevitably happen during the build process. Is there any advantage to factory cut SIPs besides time savings?

From your response, it sounds like this red iron + metal SIPs setup will work, though perhaps it's not the most cost efficient route.

greenbuilds, yes steel SIPs and red iron are made for each other , but some varieties do not require the frame at all, when I was contracting we would build up to 3 stories tall and 12,000 sq. ft. with out a frame. the only time we would use a frame was over 3 stories and for large clear spans (like churches)

Chris is correct in that there was a lot of waste. I bought a first set of "seconds" panels through a "reseller" with lots of problems (some very bad quality panels). I went direct on a second set of "seconds" panels. They were very good quality and a lot less drama in the process. This thread piqued my curiosity about what I paid for panels in total per square foot of panel installed - it came to $4.55/sf. There's waste from cutting as well as using available leftover panels (I have almost 900sf leftover). I don't think I could have managed this if I wasn't so close to the plant or was trying to do this in the current economy.

In regard to solar you may want to get a better idea what the solar city glass cost per watt. "The cost of electricity" at $250/month would be $90k at the end of 30 years. I had looked at some other roof integrated solar and finally settled on standing seam and standard panels. With the standing seam you can run your wiring through the ridge cap and use S-5! clips to attach the panels with no penetrations. The cost per watt produced, density of power per square foot of roof and flexibility in repair is hard to beat.

Hi Torben, thank you for replying to this thread, I was hoping you would see it.

The standing seam S-5! zero-penetration installation sounds ingenious. Drilling a bunch of holes through a brand new roof always seemed like a compromise. I like the look of standard solar panels, plus, the clips seem to allow for easy upgrades if needed. I'll mainly need to see if they can hold up to our wind gusts.

Torben, did you use wood for your house structure? Are there any photos of the build you can share? Thanks again.

The S-5! clips have a very good grip. In my case the weakest link was the standing seam connection to the metal sip. I added a lot of screws to the standing seam installation.
The only wood is floors-subfloors and some bracing to the interior metal studs in some select locations.
I tried posting some pictures but am having trouble with it. If you send me a PM I can send you some photos that way. I really liked the way the standing seam roof worked and would highly recommend it for solar.

Hi greenbuilds, I took on a project with a few similarities a while ago. Are you talking about a really big structure, because if not you can do without the red iron frame.

I cut all my panels in the field, and would do that again. But I would however consider some changes in the design process that would eliminate cuts and eliminate waste. If you used the panel width as a design unit this would be a big help. For example if all window openings were designed to be consistent with the panel width of the product you are using, and if wall lengths were only in multiples of the panel width.

Thanks for all the info, Torben, Chris, and Jelly. Torben, your roof ridge solar install looks super clean, I think we will follow your footsteps and install it in the same fashion.

I was offline for a bit due to a computer switch but am back. Steel is in production now, and we should be getting the steel frame up in about three months. Once the foundation is ready, the frame takes 1-3 days to raise and bolt together, and then the steel SIP panels go on the roof purlins and walls. Great point about trying to reduce SIP waste, Jelly. I was actually looking at windows and doors that are at least somewhat compatible with the size of the steel SIP panels. We are trying to get the biggest non-custom windows that we can find, which so far look like 7-foot-tall fixed windows (similar to sliding door size).

Did any of you all use 4x8 foot steel panels horizontally?

One of the biggest disadvantages of the Kodiak system is that the plans are fixed in size. The interiors are open span and fully customizable, but they won't modify the exterior footprint to keep engineering and dev costs low. If I could ensure the house was multiples of 4, that would be amazing, but they won't be able to change anything for me. As it is, everything is at least a multiple of 2 and the steel is so precise that we shouldn't create too much SIP waste.

Jelly, you do have a good point about the frame, and the red iron frame isn't necessary in all areas of the house, but it's a modest percentage of the total house cost (less than $25/sf) and adds strength in these windy and earthquake-prone parts. I'm trying to overbuild in the foundation and frame and will use modern but efficient finishings to keep costs reasonable (e.g. polished concrete floors with area rugs, floor-to-ceiling but non-custom windows, contemporary but inexpensive steel exterior doors painted bold colors, off-the-shelf Euro cabinets, and doing some framing, painting, fixtures, electrical, and plumbing myself).

Our plan was to use Techno steel piles for the foundation since we're on a hilltop, not sure if anyone has tried those here. If the bedrock is too tough, we might need to drill piers in some areas.

I'll update again once we have some progress, it's great to hear that others have done similar builds.

My panels were structural, so the only place I used them horizontally was as cut-offs for awnings or interior partitions, kitchen island, et cetera.

I did concrete floors too (post-tensioned, fiber added), just went with the standard power trowel finish from the concrete contractor. Acid-stained it light colors like blue/grey with gallons from a local shop and a pump sprayer from the hardware store, sealed and waxed. I didn't bother scoring tile lines in it (just would make it harder to clean) - resembles marble or stone as is. Probably should have done control joints though, or ask concrete guys to add rebar mesh, because I do have some cracks but that's really unavoidable. Something I realized later that would make things easier is if you could stain, neutralize, and seal the concrete after it cured but before any framing was started then it would make the whole process much faster. You would however have to protect it during construction, and some colors are sensitive to direct outdoor sunlight.

Light gauge steel framing for the interior is really helpful if you're working by yourself - easy to cut with snips, carry much more at once, put all the elements in piece by piece instead of raising walls with a team.

I did the Euro cabinets too. Don't remember if I can name them in the forum, but they're Swedish and their stores are blue and yellow! So easy, look great, good price, and completely finished upon install. A nice tip I learned in the kitchen and laundry is to reduce the framing members behind the refrigerator and washer/dryer by half so there is an inset and the appliances don't jut out so far. For example going from a 6 inch steel stud to a 1 and 5/8ths steel stud behind the fridge so it will look recessed. Careful if there are cabinets going across the top however.

I guess you have your wall heights already designed, but one mistake I made was trying to make full use of pre-cut lengths of exterior panels left me with ceiling heights not standard to sheetrock dimensions after the second floor joists were hung - that resulted in a good bit of waste. Instead design for 8, 10, or 12 foot ceiling height.

I envy you, greenbuilds! Maybe I need to do this again...

Hi Jelly, wow, thanks for all the learnings. I think I'm building in a similar way as you did. Cracked floors do seem inevitable for such a large slab, thanks for the advice on the reinforcements. The saying with concrete is that it exists in two states only: cracked, or about to crack

Torben, I found an old thread from 2011 where you were talking about wood-free subfloor sheathing. Our thinking is to use fluted steel decking attached to the steel floor joists and to pour the concrete floor on that. It's common in commercial construction, but it is heavy and doesn't provide insulation. If we go that way, the main issue is then where to insulate if we go with bare concrete floors.

One unorthodox idea was to use steel IMP panels directly on the joists instead of the fluted decking and concrete. Not sure if anyone has done that here. Another would be to use a lightweight concrete or aerated concrete to provide some moderate insulation. We're still working on the shell details so there is still some time for the floor.

I've been talking to Kingspan and they don't offer metal SIPs in the US, only overseas. So it might be insulated metal panels instead, which is ok since we don't need structural anyways unless someone knows of a very reputable steel SIP dealer near the west coast. I think that with 22 or 20 gauge steel skins the Kingspan IMPs should still be quite strong. They'll be attaching to 18 gauge nlb studs.

For the door and window layout we are probably going with Milgard fiberglass Ultra windows. At 4 foot by 8 foot double pane with low-e glass, they are around $1,150 each from an orange big box chain. We'll talk to some local retailers, too. Fortunately, we won't need too many of them due to the size. The lifetime warranty sealed the deal for us (labor, materials, even glass breakage).

Greenbuilds,
Kingspan metal panels are made and distributed in the US , but are considered to be non- structural and need a red-iron frame or other support
Kingspan also makes/distributes OSB panels in UK and Europe

Thanks, Chris. Do you know of a steel-skinned SIP brand that you would recommend equally or prefer over Kingspan?

BTW, the Tesla solar roof pricing and ordering is out. Quoting Bloomberg:
"Roofing a 2,000 square-foot home in New York state—with 40 percent coverage of active solar tiles and battery backup for night-time use—would cost about $50,000 after federal tax credits and generate $64,000 in energy over 30 years, according to Tesla.

The warranty is for the lifetime of your house."

I think I might still go Torben's way and do a standing seam steel insulated panel roof and then add panels later on top of that. Six inches of rigid foam insulation under a Tesla roof would cost way over $25/sf unless they have some crazy financing options to amortize it over the 30 year period. "The estimated cost of your Solar Roof includes materials, installation, and the removal of your old roof. Taxes, permit fees and additional construction costs such as significant structural upgrades, gutter replacement, or skylight replacements are not included. The Solar Roof cost is based on estimated roof square footage for your home, provided by Google Project Sunroof where available, and the portion of your roof covered with solar tiles."

Posted By Torben on 01 Apr 2017 09:32 PM
The S-5! clips have a very good grip. In my case the weakest link was the standing seam connection to the metal sip. I added a lot of screws to the standing seam installation.
The only wood is floors-subfloors and some bracing to the interior metal studs in some select locations.
I tried posting some pictures but am having trouble with it. If you send me a PM I can send you some photos that way. I really liked the way the standing seam roof worked and would highly recommend it for solar.

I am looking into solar install on top of SIP Roof for the best price possible. found out about metal SIPs and I think that might be the cheapest way to build the roof if it won't need a roofing material on top and I can just use the outside metal of the SIPs as the roof finish. The picture you posted, is that the SIPs or is that metal roof installed on top of the metal SIPs? The S-5 Solar mount sounds like the way to go for the metal roof but you need "Raised Ribs" to attach them to. I wonder if any metal SIPs in the market now come with that option as a finish.

Posted By greenbuilds on 10 May 2017 07:35 PM
BTW, the Tesla solar roof pricing and ordering is out. Quoting Bloomberg:
"Roofing a 2,000 square-foot home in New York state—with 40 percent coverage of active solar tiles and battery backup for night-time use—would cost about $50,000 after federal tax credits and generate $64,000 in energy over 30 years, according to Tesla.

The warranty is for the lifetime of your house."

A 23-1/2 year payback?  Oh no.  Oh nononono.

If that's the case, you're likely better off going with conventional high efficiency panels on your available southern facing.
How big a system (in terms of KW) and how many power walls did you spec for?

Solar roof is just luxary item right now. looked into many times,
I can get my 20Kw system self installed for around 32K$ with a new roof price included (not even considering rebates)
a 20KW system by Tesla would cost above 80K

Posted By doctorman on 04 Aug 2017 11:06 AM
Solar roof is just luxary item right now. looked into many times,
I can get my 20Kw system self installed for around 32K$ with a new roof price included (not even considering rebates)
a 20KW system by Tesla would cost above 80K

Yeah.  That pricing is asinine...

It was a metal roof on top of a high temp peel n stick membrane adhered to the steel SIP panel. I did the roof myself - 26g material/fasteners and two days with a high reach was ~$6500 for 2520 sf. The peel & stick is expensive but was great for being able to walk the roof (albeit with a harness - roof height varied from 22 to 32 feet and I'm no fan of heights). I've seen integrated metal SIP roof panels with a larger standing seam for commercial - and they look very commercial. My system ended up costing less, I prefer the look and just the top panels could be replaced if needed. I had looked at the idea of using the peel and stick thin film solar panels between seams. They were less efficient for size, more expensive, and it would be very difficult to change out a bad panel.

Posted By Torben on 07 Aug 2017 05:15 PM
It was a metal roof on top of a high temp peel n stick membrane adhered to the steel SIP panel. I did the roof myself - 26g material/fasteners and two days with a high reach was ~$6500 for 2520 sf. The peel & stick is expensive but was great for being able to walk the roof (albeit with a harness - roof height varied from 22 to 32 feet and I'm no fan of heights). I've seen integrated metal SIP roof panels with a larger standing seam for commercial - and they look very commercial. My system ended up costing less, I prefer the look and just the top panels could be replaced if needed. I had looked at the idea of using the peel and stick thin film solar panels between seams. They were less efficient for size, more expensive, and it would be very difficult to change out a bad panel.

that is cheaper than shingles, if you can give me some more detail as where and what model peel and stick and metal you got that would help a lot so you got raised ribs metal roof on top of a flat metal SIPs? I assume the main reason for metal roof over sip was to protect the SIPs as they are structural and you can change the roof cheaper and easier down the line? how long you expect to get from your metal roof?