This is a fantastic forum...found it very useful (Thanks~creators & monitors!).

This will be my first project with SIPs and hopefully one of many.

We are in the very moderate Southern California climate ( 40 to 90 degrees near coast).

Is it "over kill" to use SIP roofing? Extra cost when accounting for labor??

 

Loads (we're considering a Cedar/Ceramic at 600 Lbs/Sq) any thoughts on SIP stability with these heavier loads?

John

 

There are a number of factors to consider in your roof. The most important are cost and comfort. If cost, resale value, and ROI have higher priority then you will probably not upgrade your SIP roof upgrade will show little or no appreciation in the appraisal done on your home. SIP roofs work well where there are fewer cuts, higher cost of labor and skilled labor available as well and higher returns on the energy savings. Or in your designs, vaults are probably best done with SIPs but don't count out a scissor truss.

I am a dealer for EZ Build. The reason we exist is that we market floor/wall/roof in a system complete with stamped structurals and shop drawings that tie everything together. This way you can use I joist floors and a truss roof and that a single stamp will integrate the components which is most important in your strict building code area. Whether you use our company or someone else, you will need to jump through all the hoops and they are complicated in CA.

The value of SIPs are mostly threefold. First is structure. Second is seal. And third is insulation value. Every roof has structure so the value between them is mostly in design. With a heavy roof, you will no doubt need purlins or structural members in the SIPs to support your spans. A seal can be accomplished with less money by spraying a couple inches of foam in your ceiling. Insulation value can be increased by heel height adjustments in trusses and blowing more insulation over your foam to get a better r value then what you might get in SIPs alone.

With all that said, your SIP upgrade will provide you with better comfort, but in your area you might not realize any gain. I live in Texas with a more severe climate. It costs me $30 to air condition the house per month and I have virtually no cost in heating the house without a SIP roof. I am probably saving an average of $50/month on my electric bill so I will have an ROI in a few years. Even if a SIP upgrade doubled the value of my roof, I would only save $15/month X 8 months or $120/year. That is less then 4k over 30 years. Since my upgrade would be at least 4k I probably would not get a return on investment. Since your low temp is higher then mine and your high temp is lower then mine you will probably find the calcs to be similar unless your cost of energy is significantly different.

You might want to check the history of this topic. It is kind of a hornet's nest. I will no doubt get blasted for not supporting SIPs. But I just want you to do the math before jumping in. And you asked a very good question. Let me know if I can help.

Just watched Tommy on This Old House showing suggestions for SIP roofing. He uses 1 x 2's strips on top with another panel over the SIP then ridge and roof vents to prevent mositure build up...


Is this overkill with the new wraps and membranes????

If you add a panel on top of a panel you will have to pay for the materials and the labor. If you were on the fence about ever trying to provide a return on investment, you have now landed on the side of looks cool but costs more then it saves. Maybe you should consider using $100 bills for wallpaper??

I assume that you are talking about plywood or OSB on top of a SIP roof panel?

Tommy Silva usually utilizes Best In Practice methods. The wildcard is your local conditions.


Funny. It's interesting that all of your posts follow the same pattern:

• SIP roofs are too expensive...
• SIPS are too expensive(unless you are selling them)...
• Gota get a shameless plug in for Doggy-Build(but haven't figured out how to get your promotional sig to work)...
• Everything but sticks are too expensive...
• Acting like an expert, only fools some of the people, some of the time...
• Everything Must have an ROI(How do you justify food?)...
• Spray Foam is a good solution(instead of using SIPS). Sometimes. At a cost of $0.60 - $0.90 per sqft per inch, it's not inexpensive...
• Engineering is something that Doggy-Build offers, and, apparently, all of the other SIP manufacturers are clueless, and use napkins borrowed from McDonalds...
• Shipping building materials(the ones that you can buy locally) across the country makes economic sense(After all, it's only a couple of bucks a mile)...

Oh, no! Yet another 'attack'. Oh my. Yea, I know, I'm 'picking' on you.

I respect differing points of view.

I don't respect disinformation. Especially when it's designed to bash SIP technology for someone's own profit motives.

JC,

Your post offered nothing but bashing and name calling. It seems odd since I believe we both use the same supplier. And seems really odd considering you didn't address the issue at all. How much can someone really expect to save with temperatures between 40 and 90 degrees? Cost should be a major factor to consider because SIPs don't really offer much more to justify a significant upgrade. You seem to take offense like SIPs is a synonym for your mother or something. The post proposes to build a system that will have a roof that will be significantly higher then a house built across the street. Why would anyone one do that without some kind of ROI? If it is energy savings, great. If it is a builder like Pulte that can build faster and provide the energy savings with a moderate upgrade cost, great and so on. But if someone saw it on tv and is paying significantly higher to get an upgrade without any expected returns then it may just not make sense. That is ok and you will just have to accept that position whether it makes you angry or not.

The simple fact is that SIPs may not give you any advantage when trying to sell your home. That is up to the appraiser and the buyer. My former post showed that I was fortunate enough to get a 5% increase in value for my upgrade, but I had to go through two months of mortgage dealings in order to get approved because SIPs are not conventional technology. And I have no idea if that value will carry to the next buyer. And I compare my SIP upgrade to other upgrades. Locally a fireplace brings an appraised value of $800 but costs more to install. I am believing that the fireplace upgrade is a bigger concern then insulation value considering local comments. Additionally a pool brings little or no value to a home but is an expensive upgrade. But I can clearly determine that a pool has entertainment and health values. So do I spend 8k on a full SIP upgrade or put in a pool?

Finally I would agree with you on shipping costs. They are significant and some places just don't work. On the other hand the cost of labor can offset distance in areas like New York. Now if the SIP organization could complete a prescriptive method for utilizing SIPs like sticks and ICFs, we could start realizing a gain in popularity due to a reduction in engineering costs. Until then I believe you have to look at each case on its own merits. And the simple fact is, I don't want to sell SIPs to someone if it doesn't work for them. I will build them a stick house if that is what they think is best. But I guess that disappoints you.

Hi John in the OC,
I have to agree with Mike on this one, only I'd like to clarify one point:  I believe that SIPs are ALWAYS better than stick when it comes to walls, but the extra cost of doing a SIP roof (material & labor) is not always warranted.  SIPs work great with cathedral ceilings and in a lot of instances, we have found that if you are doing a cathedral ceiling, it is best to use SIPs over trusses and stick framing (cheaper, easier, more energy efficient).  However, like Mike said, it would not be beneficial to use SIPs on a roof that had, for example, tons of different elevations which would work better with a scissor truss.  When it comes to SIP roofs, you do have to weigh your cost vs benefit ratio.  We only sell what works best for the customer; we look at the overall system and how it works together...you are still saving a heck of a lot of $$ on energy costs by only going with SIPs for walls and you'll still see ROI with only SIP walls.  Particularly in CA where you are required to have Strong Walls because of your code, SIPs are definitely a cost saving alternative.

Hope this helps!

Are you sure that the load is 600 PSF? If that is the case I am guessing that is dead load and a live load must still be factored. Depending on your span you may have trouble with what ever you choose: trusses or SIPs.

DC

RE"Are you sure that the load is 600 PSF?" That was what the ditributor called out as per "Square" not SF.. behaps case In California there were several 'manufactured home law suites over roof load failures when asphalt was chained to tile.

It is my understanding boith SIP and truss are typically much stronger than the manufactured homes...

Hi John,

PSF (pounds per square foot). As a roof truss manufacturer and a SIP manufacturer, I would be very careful. Short spans may not be a significant concern, however long spans with that kind of long term dead load: your roof design will be very interesting. General clay tile (concrete tile) is 12 to 20 PSF, and that creates fits for roof trusses.

DC

Hi John:

If it is 600 Lbs per square ... then I would say it is intended to imply 6 Lbs/sft (6 Lbs per square foot)!

Hi John and Yogia,

Hey I am Canadian, when I see Lbs/Square, I am immediately thinking PSF. I am not familiar with the "per square" system so I hope I did not side track your original question.

Sincerely,

Dave

I appreciate your post hopefully you didn't get "blasted".  I live in Texas also and have been trying to get the right info to determine if sips are economically sensible for me.  I think the product in general is terrific but not sure for the Houston area. 

My question is, How do you put together a stick built (taking advantage of our cheap labor since most subs here are familiar with stick) while getting as close to the sip advantage of lower utility bills.  I'm in the design phase now so I can plan and design for anything, just not sure what will make the best economic sense.

Try this: Building America Best Practices Series: Volume 1 - Hot & Humid. Loads of good info.

Good Luck!

Thanks a million!  That's what I've been looking for to get some basic knowledge.  I've been talking to a sip manufacturer in New Braunfels and will be sending prelim plans to them for an idea of sip cost but I wanted to do more investigation to other methods before I go with sips.  My other big concern is finding a framer.  No one has built a sip house where I live (about 50 miles from Houston).  And I may want to get some one with experience to get at least a little benefit in labor cost.  Although we have some good framers here, they would be very conservative in their bids on something new like sips.  Thanks again for your time!