Are there any metal sips out there that can be used as exposed roofing. (not a sip roof with a roofing material over it, but actually leaving the sip exposed as the roofing)

Posted By wild01 on 09 Feb 2011 01:24 PM
Are there any metal sips out there that can be used as exposed roofing. (not a sip roof with a roofing material over it, but actually leaving the sip exposed as the roofing)

Yes with some limitations: simple gables simple hips, simple shed roof. No vallleys or intersecting roofs.

Advantages:  cost,  time, functional

Disadvatanges: you can have any color you want as long as it is white, upcharge for color is steep

Ther are some Insulated roof panels on the market that are aesthically more pleasing, the drawback is they have little structural integrity

examples:

Wild01,

There are standing seam and deep ribbed metal SIPs that are usually used for warehouse roof applications. The issue when trying to use them for residential applications is the look of the low edge of the roof when finished. The system requires that a large profile metal gutter be attached along with closure pieces to seal off the thickness (foam) of the panel. On the average residential project this would look very industrial.

Posted By JeffD on 09 Feb 2011 03:52 PM
Wild01,

There are standing seam and deep ribbed metal SIPs that are usually used for warehouse roof applications.

they are marketed as Insulated Panels, not SIPS

Ther are some Insulated roof panels on the market that are aesthically more pleasing, the drawback is they have little structural integrity

yeah this has throw me somewhat, I just don't understand why the more attractive standing seam panels are not rated for loads w/o support (they're just irp's not sirp's) when they are made from the same materials and often have a heavier gauge metal cladding.

the frictionfit panels concern me b/c of the joints, I would think they would be very leak-prone on a roof

Kingspan and MBCI both have standing seam roof panels that can handle loads similar to their regular wall panels. They market all their panels as Insulated Metal Panels rather than SIPS. You can do custom extrusions at the drip edge to lessen the industrial look. Gutters are not necessary. Either way the standing seam roof will still look different than most residential. The seams are usually 42" on center and taller than the 12-18" on center seams of most residential roofs. The panels have a special joint that is integrated with the standing seam to seal out water.

I understand that all of Kingspan's panels are non-structural, at least that is what their rep told me recently.

It depends on who you talk to at Kingspan. They certainly are not marketing their panels as SIPs. Their certified test results show their panel strength slightly exceeds many other metal SIP producers when comparing panels of the same thickness. At just over R-8 per inch their insulation value well exceeds EPS panels.

thanks for the info finally found the span charts on kingspans website, their 900 series 5" or 6" panels would work. I can span up to 16' and still meet a 20psf snow load.
woohoo, anyone know a ballpark price per sqft on those.

Torben,

Who can I talk to at Kingspan about structural panels?  I may have a project about 60 miles from their plant.

wild01,

The 900 series are not standing seam. You will want to check to make sure this is the profile you want. I have never priced these ones out new. I have checked the KingZIP (their version of standing seam) and these are pricey when purchasing new in small quantities. I was seeing $7-9/sf depending on options for the KingZIP. I found MBCI in Atlanta to be a better deal and more responsive. I found in my case it was much cheaper to buy overstock panels from Kingspan and cover them with a standing seam roof (~$5/sf materials). I also like the idea that if I have something messed up on a roof panel I don't have to tear the roof off to the interior to fix it. This was more of an issue to me because I'm considering using thin film solar strips adhered to my roof between standing seams. If I ever had to remove the solar strip I would need to remove the roof through to the interior of the house.

Alton,

I don't know of any of their salesmen who would support their panels as SIPs. Their market is cladding for commercial/warehouse buildings and they do not appear to be interested in expanding into residential. To them I think it looks like lots of risk with no real reward. Even their pricing structure discourages it. Their volume discount would apply to most commercial jobs but most residential jobs are too small to qualify for anything but their highest per square foot price. The only metal panel manufacturer that I've seen interested in supporting their product as SIPS for residential is Structall. I personally chose to skip that one.

You can certainly purchase Kingspan or MBCI panels but you and/or your engineer would be responsible for the application you use them in. When I last checked Kingspan's FL product approval number had not been updated and MBCI was just getting theirs.

Torben;

 

Kingspan's FL product approval # is for roofing , installed over purlins, not for a structural component

Above is a typical eave detail for a metal panel that has thickness to it.

Torben,

"You can do custom extrusions at the drip edge" do you mean custom break-metal? Custom made aluminum extrusions are very expensive but possible.

Do you have a detail of the roof edge you propose or a description?

If the fascia closure piece fits over the top panel skin it will eventually leak and trap water in the fascia then slowly drip and cause mildew issues. If sealant tape is used it will degrade and look terrible after a year or two.

A custom break-metal channel fascia could work if one would be willing to slot the foam at the top edge of the metal SIP and slide the top leg of the channel into it or have the top skin of the SIP run a half inch long so it could be bent over the fascia. But one would still have to fasten it and this would an aesthetic issue, although minor.

If one wants to save first costs and buy a fiinshed roof later, that is definitely an option with standard residential metal SIPs.

Torben and Chris,

Thanks for the insight into Kingspan.  I would prefer to use a metal SIP that is reasonably priced and supported for residences.  I was looking at Kingspan because of their proximity to my proposed site in Ocala FL.  The SIP that I am the most familiar with and have used is G-SIPs in Bolivar TN, approximately 685 miles away.

Torben,

I am aware of the profile on the 900 series- it appears very similar to pro panel which is the metal roof of choice around here, so it would blend in better in a residential neighborhood. What I am trying to develop is a small inexpensive house that could be installed in a very short time w/o the horrid drawbacks of a modular/trailer. I'm still in the feasibility/cost analysis phase at this point. What I'm trying to come up with is a very simple 16to20x32to40 house with 2 to 4 sleeping lofts as a starter/vacation/low-end home. for ease of install I really want everything to be as simple as possible. I'm looking at 10' side walls with a 8x12 pitch roof and loft floor joists attached to the walls at 8' basically doubling my usable sq footage w/o doubling the heating requirements for the house.

My basic idea is a house I can retail for 40k install in a week and turn a fairly decent profit. I've never built with sips personally, but I have been on several projects where they where used and they seem like an ideal product for this type of use.

On a separate subject, while I'm not well versed on sips I am very knowledgeable about solar, I've lived off-grid for 10 years depending solely on solar for all my electrical needs. The stick-down solar panels have some very serious problems and DO-NOT perform well over the long-term! heat buildup due to them being in direct contact w/the metal roof causes premature failure of the cells which are a-si rather than c-si, (amorphous is already an inferior product that does not last as long as c-si) they also take twice as much room as a crystalline panel, they are easier to install and require no mounts, but there have also been issues on some w/adhesive failure. basically, unless you can come out with an installed price 1/5th that of a c-si panel system, they are a waste of money. you can install panels on a roof fairly easily using standoff mounts and uni-strut, but if you have the room/non-shaded area, I would recommend ground mount as the way to go.

best place to go for info on solar http://www.wind-sun.com/ForumVB

best (cheapest) place to buy solar panels is sunelec.com (although their web site is down today for some reason) they are based in miami and you can even pick the panels up from them to avoid shipping. only thing I don't like about em is if you call them on the phone half their employees aren't the best with english, just hang up and call back

Kingspan's FL product approval # is for roofing , installed over purlins, not for a structural component

yes but as long as the space from the ridge beam to the outer wall does not exceed the maximum span between purlins in the span tables, they could be used w/o need for additional support and still meet code.

ROOF PANEL SPAN IN FEET (L/240)
5 8 10 12 14 16 18
PANEL THICKNESS DESIGN LOAD IN PSF
2” 34 23 17 – – – –
2.5” 41 29 22 16 – – –
3” 48 34 27 20 15 – –
4” 65 49 40 30 23 18 –
5” 68 53 43 33 26 20 16
6” 72 56 47 37 30 22 18


so with a 6" thick panel I could install a ridge beam down the center of a structure and and span 10' to an outer wall on a 6x12pitch leaving me a 12.8' span and have a snow load of >30 psf

Jeff, The way I've seen it is the bottom skin and foam are cut back leaving the last inch or two of panel just bare top skin. The top of the Z-shaped extrusion is attached to the bottom of the exposed panel skin and then the bottom of the Z is attached to the full width panel. I think the attachment was with rivets and sealed with caulk. This is significantly less metal than the gutters and can work with roof overhangs. Besides the industrial look I didn't like the fact that the gutters require the roof to essentially end at the wall. This makes it virtually impossible to take advantage of sun angles for seasonal efficiencies.

wilde01 and Chris, The actual test data I saw is several inches thick and covers wall and roof panels for several types of attachments, loads and even temperature differences between exterior and interior side of panel. I didn't see any reference to purlins but they do use their own clip/bolt for most attachments. SIP bolts can provide similar (and even better) attachment but you have to correlate contact area of the attachments. The product approval this test data is attached to has expired. Interestingly though they are current on their Dade county approval.

Posted By wild01 on 10 Feb 2011 01:02 PM

so with a 6" thick panel I could install a ridge beam down the center of a structure and and span 10' to an outer wall on a 6x12pitch leaving me a 12.8' span and have a snow load of >30 psf

thats a pathetic span capability