Im new to the world of sips and im continuing to read here about Sips, etc. Also, I dont have a SIP builder thats local, so im going to have to go 3 hours south of me to find someone. But trying to have alot of knowledge beforehand.. My question are there things that I should know ahead of time, things that could be considered GOOD SIP building practices vs. BAD SIP building practices that someone who isnt on the level may try to do. Im concerned with thermal bridging and anything else that can make my house more air tight. I live in northern Maine and we have huge temp swings with alot of winter thats under zero degrees. Thanks

Where in Northern ME are you. I have 3 crews in Maine that work with sips that would travel. I have one that is exceptional on the installation. We just did a job in Saco that only took them 3 1/2 days to cut/route/ install and seal a roof system for the new transportation building in Saco. they are going to Albany NY at the end of the month so I don't think that Northern Maine would be to far. I am a manufacturer in NH. if you would like to discuss futher please feel free to contact me. [email protected] or 603-209-4857

Im in Houlton Maine, 1.5 hours north of Bangor. Im wanting to build a 1500sq ft ranch... Striving for the tightest house in Maine :)

As an architect I have no ax to grind or horn to blow for any product. All products have their pros, cons as well as potential hazards or built in "forgivenenss". SIP's in my view are a great product performance-wise, To acheive a thermal performance with equally economic (not $$$ but genericly economic) use of materials is nearly impossible with any other system I know. What's the down side? In my view it would be durability. That is not to say they are not durable but in my thinking all materials will fail eventually and I try to imagine how any system/product will fail in order to understand how best to install/use/maintain it. In my imagination the eventual failure of a SIPS structure is not pretty since I envision the degradation of the OSB and once the OSB has failed there is truly nothing left of your building. What does a 150 or 200 year old SIP look like? No one knows. I AM NOT saying this is reason to void SIP's - in fact I expect to use them on my own house. But I go in knowing intuitively that SIPs and water will not get along well for very long so control of moisture (liquid AND vapor) are vitally important. For example, do you know anyone who has replaced a roof that wasn't leaking? - someone who said "Gee, that'sa 20 year roof I put on 20 years ago - time to rip it off and repalce it...." I don't know a soul like that. Everyone waits till the roofing begins to leak, maybe a little, maybe a lot. What happens to a SIP roof that has had a roofing leak for a year or two? I don't know but it doesn't sound like fun..... Bottom line, SIPs are great but require careful and durable methods to keep them dry for the life of the building - because their life IS the life of the building.

Birdman,

Whats your thoughts on Steel Sips in trying to eliminate the osb/water from the concern?

Oh and I appreciate you candid thoughts, refreshing....

You didn't ask me, but I'll give my opinion anyway.  The first option is to avoid OSB.  Fiber cement, metal, or MgO (magnesium board) would be the non-moisture-sensitive options.  However, OSB is the norm in the industry, especially up in your neck of the woods, so you may have trouble finding non-OSB SIPs, and they would probably cost more.

You can't protect OSB (or any other material) in the long run by trying to achieve perfect sealing.  Water will find a way through eventually.  So you have to give it a way to drain away and/or evaporate away.  A drainage plane is the best way to do this.  You need a vapor barrier on the outside of your SIPs, and then a small space (from 1/16" up to a couple of inches) between that and the cladding (siding, brick, stucco) to allow water to drain away.  A bigger space can be ventilated to provide not only drainage but rapid drying -- this is what I would recommend for the roof, but it might be overkill for walls unless you get a lot of rain.  If you're going to use stucco, use either a double layer of building paper (which creates a drainage plane between the layers), or use a stucco drainage mat made for the purpose.  If you're using wood or fiber cement siding, install it over furring strips to create a ventilated and drained space behind the siding.  Vinyl and metal siding are self-draining.

Proper detailing around windows, doors, foundation, and roofs is also critical.  Joe Lstiburek has lots of good information on moisture control in his books and at www.buildingscience.com.

Well, I haven't thought much about steel SIP's and can't say I know anything about their detailing etc. I would apply my same technique, though. Project into the future and imagine them failing (as all materials do). Then try to predict how they would fail.... I would imagine corrosion due to moisture would be the biggest threat (or possibly galvanic action is mixed with other metals) so I would look at coatings, what happens where fasteners penetrate coatings, how are exterior/interior finishes applied. One rule I apply to all "assemblies" is "Design to keep water out, know that water will get in anyway, so design to allow that water to get out" This has stood me in good stead over time and when I violated this rule I've usually regretted it....

Looks like Mortman and I were tyoing at the same time - and we seem to agree. I would add that you must think about moisture vapor drive from inside the building as well as exterior liquid water. As I uderstand it sealing SIPs inside is vital. There were some early catastrophic SIP failures in Alaska (hearing alot about Alaska lately) that were due to unsealed panel joints. I second Joe Lsiturbruk (sp?) If you follow Joe the Building Scientist to a "T" you won't go far wrong.

Wow, now you really have me thinking......

I certainly want my house to last more than my lifetime and for my kids. There is alot of water, weather change extremes here in northern Maine....

Steel SIPs are estimated to last in excess of 300 years, accelerated aging tests have shown they are far superior to OSB and remain unaffected after 15 aging cycles

Seriously? Is this discussion about building a rock solid awesome house that will last >300 years? I got one word for you 'concrete'. Come on, OSB is gonna fail after 250 yrs. ... better build with something stronger? Please, these cookie cutter homes in all of these cookie cutter neighborhoods ain't gonna last past 100 yrs. Trust me, the builders are not trying to build for the long term. The OSB SIPs are better than these things (assuming the manufacturer is squared away).
If someone is truly looking to build a house to last the ages, then you are going to have to build with concrete. Check out the pyramids. Steel last longer/stronger than OSB. Sure, I'll agree with that but what is the difference between a house lasting 250 yrs. and 350 yrs. to the builder of today? Is it worth the extra $s? Maybe, that is the builder's decision. However, all this chicken little my house is going to fall down because it is made out of OSB is silly and mis-leading. Next your going to tell me mice are eating my house. Oh wait, you already did.

Amen.

Mark

If you're looking for the most cost effective, energy efficient structure that will last many many generations with proper installation than you need look no further than OSB SIPs. Not all OSB is created equal nor are all OSB SIPs. We have an install crew based in Maine & would love to help you make an educated decision on building with SIPs. Please feel free to email me ... [email protected]

Jeff;

what is different about you OSB?

I've had a quote on steel SIP's, and didn't find them to be much more expensive than OSB. If I can afford it, I plan to go steel SIP's, fiber-cement siding, and steel roofing, which should last the 20-odd years I'll need it for, but more importantly in my rural location, it should be pretty fireproof, and enjoy lower insurance rates because of that. Haven't found a termite that eats steel, either. I may even go all steel framing, so if said termite tunnels up through the foam to my roof structure, he won't find anything there, either. Of course, the way real estate is dropping here in FL, I may just have a single-wide up on blocks!

If you have steel sips the is no way for a termite to tunnel anywhere.  I went with steel framing too, and it was very good. All steel including shingles and we are basically fire proof.  If a fire got hot enough to melt us down then we wouldn't know about it any way 'cuz it would be a big bomb blast or something.  Living in FL you wont be disappointed in going with steel and I found out it was cheaper than OSB all things considered, such as quicker install, no heavy equipment, less labor and quicker finish means less construction intrest, no need for vapor bearrier, etc, etc.

I have a question about installation in general.. if you have a SIP panel and cement siding and you are in a rainy climate... would felt wrap be a better choice or using rainscreen construction. My concern is that the idea behind rainscreen construction is that it allows drying of water between exterior and interior.. but with SIP's how much indoor air is going "out" to circulate behind the siding.. particularly siding that is cement?

The drainage space in a rainscreen design is usually ventilated to the exterior, using insect screens to keep them out of the space while allowing air to flow in and out.  (Products like Cor-A-Vent are designed for this purpose.)  It's not indoor air that's drying out your cladding -- typically outside air would enter at the bottom, flow upward, picking up moisture as it goes, and then exit at the top.  This happens automatically due to "stack effect", so no fans are required to move the air.  The ventilation air never crosses into your interior space; it's entirely meant to dry out your external cladding.  There is no doubt that a properly done rainscreen is better than (or at least as good as) building wraps alone.  It's very important with a porous cladding like fiber cement or especially wood to allow it to dry out, so the rainscreen design is really best.  If you live in a dry climate, you could probably get by without it with fiber cement siding, but you might void your warranty.

I should also say that in a rainscreen design you will generally still have a building wrap (vapor barrier).  The order would be, from inside to out: SIP, vapor barrier, furring strips, siding.  The ventilated drainage space exists between the siding and the vapor barrier.  If your SIP has metal skins you could (and probably should) skip the vapor barrier.

Eco-Panels (www.eco-panels.com) has the only true continuous thermal boundary in the SIP industry, but with that said, shipping from NC may add much more to your budget. Have you checked out Winter Panels PUR SIPS in VT? Murus is the closest product to the Eco-Panels that I know of and they are located in PA.

As for good and bad---buying a SIP that is very integrated will save you a lot of time and headaches. PUR SIPS have better performance than EPS. I've seen too many problems with basic SIP packages that cost less, but require a lot of on site work to get them finished. The kiss notion of "Keep it simple stupid" is very applicable in the SIP industry.

Hope this helps.