Dr. William Miller, building scientist at Oak Ridge National Laboratories, has performed extensive testing on a variety of roof systems. I have seen these tests myself and have also heard him state explicity that EPS sip & metal roof systems should be approached cautiously as they have seen delamination in actual testing. Don't be fooled by a widespread use and flashy marketing - Europe also once widely used EPS panels and now use is very limited due to higher insurance industry regulation and the lack of a well funded industry lobby. EIFS was also once a very popular EPS system in the US.

I suggest you contact Dr. Miller directly through ORNL's BEP. Note he is not against EPS entirely, and in fact will actively promote it when used properly and safely (as would I), he just has concerns because they have seen the delamination effects in actual testing. I believe the concern is specific to where metal roofing is employed, of which this discussion post specifically relates.

Eifs and SIPs have nothing to do with each other.
 if there is some report or documentation to demonstrate a problem then I wish you would just post it.
Until then please quit spreading unsubstatiated rumors. We have used steel roofing over SIPs roof for years without incident in South Florida.
Thank You!

I suggest you guys review R-Control documents 2064 & 2066.

They recommend that their panels should not be exposed to temperatures over 165 F and that a ventilated roofing system is recommended if the roof temperature is expected to exceed 175 F. They further state that some roofs can reach 200 F.

Personally I would not take the risk.

I read the docs, I would have more concern with black asphalt shingles directly attached rather than a high reflection metal roof.
I personally have not seen even darker steel roof getting over 150, the bare OSB left in the sun will reach 145 on its own.
the docs do not indicate not to use in direct contact, it says to use caution, which is a prudent statement expected by any manufacturer
a proper high temp underlayment is more important than anything else.
I wonder how they feel about torch-down roofing on low sloped roofs? the temperature there is much greater where an actual flame is in contact with roof membrane.

After going to Dupont's website and looking at this product and it's spec's I don't beleive this is the right application for this product. This product has a dual purpose: 1. To reflect heat to the vent between itself and the roofing membrane. 2. To vent the attic space thru the breathable part of the wrap.

Putting a Sips on either side of this product defeats it's purpose.

Here's the site I took the
information
http://www2.dupont.com/Tyvek_Weatherization/en_US/assets/images/flash/index.html

This is so far from the truth that it's just embarrassing to read. Why do you post things you know nothing about?

I was hoping someone could tell me how they modified their fastener connections for installing a metal roof on metal SIP panels. All the metal roof installation specifications I've seen are for screwing the metal roof into plywood. A #10 screw into plywood has a pullout load of approximately 275 lbs. A #10 screw pullout value in 26 gauge steel (Metal SIPs) is only about 124 pounds. At first glance this makes me think I have to cut my screw spacing by over half.

I was also wondering how others have overcome having their SIP panel joints telegraph through their roof panels.

I would greatly appreciate others input.

Posted By Torben on 07 Jun 2011 09:02 PM
I was hoping someone could tell me how they modified their fastener connections for installing a metal roof on metal SIP panels. All the metal roof installation specifications I've seen are for screwing the metal roof into plywood. A #10 screw into plywood has a pullout load of approximately 275 lbs. A #10 screw pullout value in 26 gauge steel (Metal SIPs) is only about 124 pounds. At first glance this makes me think I have to cut my screw spacing by over half.

I was also wondering how others have overcome having their SIP panel joints telegraph through their roof panels.

I would greatly appreciate others input.

Torben;

I sent you in a PM our engineering analysis for the New Tribes Mission Project , 24 ga. standing seam over 26 ga. steel, you do need to tighten up the screw pattern, but you will see on the data the screw pull out is 192# per screw. It is in the same wind zone as your project and would be the same for your job.
We have never had "telegraphed " joints it must be a characteristic of your panels, I beleve the joint is more sever than ones we have used, even still I can't see how it would be seen thru the finished roof? unless shingles were used

Thanks Chris, I haven't received the PM yet but I will look again in the am. You're correct all Seminole County is 120mph. I have not installed the roof panels yet but was concerned because my joints are more severe than yours. It isn't anything obvious from the ground so perhaps there is nothing to worry about. I had heard of issues of "oil canning" on standing seam roofs when the surface is out of level so I was checking if there was anything else I should be doing.

sent it to your e mail, the flat ribbed or striated flats help eliminate oil canning, but oil canning can occur on any substrate wood or metal

Torben,

Make sure you are using some kind of synthetic slip sheet under the roofing to isolate the metal SIP from the metal roofing so they don't abrade each other. I have found that a self adhearing bituminous roll underlayment with a high temperature top sheet works well and is worth the cost. This will also cut down on noise from heavy rains substantially and keep you SIP joints waterproof long term. It will also give your roofers better traction when installing. You probably know how slick those panels can get. Roofers can charge you a premium if they think the job is more hazardous than usual.

.

Thanks for the good advice. I'm planning on using a high temp peel and stick.

Chris, thanks for the engineering report. That was really helpful. It certainly increases my comfort level with how I was planning on doing this. I was surprised by the difference in pullout strength between different brands of #10 SMS. I doubt in practice they are that different but I'll still use the better rated brand.

I know this is an older thread, but for anyone who comes across it:

I'm in Quebec, just north of the Adirondaks NY and I'm am re-doing the standing seam metal on my SIP (polyiso and OSB) roof. Here are a few ideas from my research:

Raising your metal off of the SIP deck on some strapping is a good idea for your climate. In the warm summer it allows an air space to release the heat build-up from the metal and would reduce any conduction of the heat into the SIP. Perhaps more importantly, in your cold winter and freeze-thaw cycles it will keep the metal as cold as the air (there will be no conduction of heat from the SIP to the metal) and help prevent ice-damming - very important! My original metal roof was not raised and with a fairly low angle to it, the ice-damming has been bad. I experimented and raised a section of the metal and over the course of the last two winters the reduction in ice-damming for that section was significant.

That venting space between the standing seam metal and the SIP roof deck, 1-2" depending on the strapping, is also good because it would ensure that any moisture that might migrate through imperfect seams of the SIP panels would also have a chance to dissipate.

Avoid ice/water shield. While it would add waterproofness to the SIP deck, as was mentioned earlier, it can trap any moisture or condensation in the top layer of the SIP and lead to degradation of the panel.

How then to add some water protection to the top of the SIP and below the raised metal? Instead of conventional roofing felt which is not really breathable, look at a product like Delta -Maxx Titan ( http://www.cosella-dorken.com/bvf-ca-en/products/roof/underlayments_pitched/products/maxx_titan.php ) which is a water-resistant, yet breathable, reflective roofing underlayment. It adds water protection from exterior moisture that gets between the metal and the SIP, but remains breathable so that any interior moisture vapor coming up from the SIP can escape. An added bonus is that its reflective topside is supposed to reflect some of the heat radiated from the metal roofing back into the venting air space and reduce the heating up of the SIP in the summer.

Good luck!

Mike

On advice i recieved on this forum i had the roofers install 1x4 battens vertically, and over that horizontally giving us a 2 inch air gap. We used 30 pound felt instead of ice and water shield since it would dry if ever it got wet. I choose true standing seam with no exposed faseners since they have much less chance of leaking although that increased the price ENOURMOUSLY. We place light breathable foam at the ridge and the eves to alow air to circulate. We choose unpainted galvalume for the metal since it reflects heat better than almost any other color. The roof was the second most expensive part of the puzzle after the sip package but it should last longer than i do. The overhangs on the house were all added after the fact, stick built onto the sip structure. The ridge beam runs the entire house. Throughout the day as the sun hits diffrent places on the roof it expands making very low noises every so often that i find pleasing. My house talks!

Some pics.

Brawler,

Do the hidden fasteners allow the roof to move easily?  If so, what is making the low noise during expansion?  It almost appears to me that the fasteners are slightly binding the metal roof and that the roof moves only after enough pressure has been exerted thus making the noise during release of the fasteners.

Have you noticed any oil canning in the roof?

My original metal roof was not raised and with a fairly low angle to it, the ice-damming has been bad. I experimented and raised a section of the metal and over the course of the last two winters the reduction in ice-damming for that section was significant.

Yes, no external side non-vapor-permeables and a vented roof or attic in one form or another is the best way to go.

Alton the noise is definently oil canning, i just couldnt come up with the tern. It happens during heat up and cool down but it is very muted. I think the panels can move up and down but not along thelenth of the roof.

Galvanized (when new) and white steel  have the same reflective values, however white roofs have a much better emissitivity value and will be about 20 degrees cooler than galvanized