mjmeno
New Member
Posts:5
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| 12 Apr 2013 06:53 PM |
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First, thanks to all for the fantastic information provided in this forum. Armed with the info here, I've decided to pursue SIPs for construction of my new home in a west valley suburb of Phoenix, AZ. I have created what I believe to be a buildable design (with Sketchup) and am ready to hand the project over to professionals.
The home is to be built on a 1 acre lot, approx 3500 square feet, flat roof, modern southwest style. I plan on 6 inch SIPs and a truss roof (spray foam insulation), 4 inch SIPs for the garage, although I welcome any comments advising alternatives from this community.
Primarily I'm curious if anybody has any recommendations on professionals in my area that would be interested in bring this project to fruition. Engineers, SIP dealers, Builders, etc. Any help is appreciated.
I originally wanted to pursue being the GC for the whole project, but time constraints (and motivation to maintain my sanity) have led me to look to hand this over to the pros.
Thanks in advance!
Michael |
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cmkavala
Veteran Member
Posts:4327
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| 14 Apr 2013 01:35 PM |
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Posted By mjmeno on 12 Apr 2013 06:53 PM
First, thanks to all for the fantastic information provided in this forum. Armed with the info here, I've decided to pursue SIPs for construction of my new home in a west valley suburb of Phoenix, AZ. I have created what I believe to be a buildable design (with Sketchup) and am ready to hand the project over to professionals.
The home is to be built on a 1 acre lot, approx 3500 square feet, flat roof, modern southwest style. I plan on 6 inch SIPs and a truss roof (spray foam insulation), 4 inch SIPs for the garage, although I welcome any comments advising alternatives from this community.
Primarily I'm curious if anybody has any recommendations on professionals in my area that would be interested in bring this project to fruition. Engineers, SIP dealers, Builders, etc. Any help is appreciated.
I originally wanted to pursue being the GC for the whole project, but time constraints (and motivation to maintain my sanity) have led me to look to hand this over to the pros.
Thanks in advance!
Michael
Michael,
Not sure why you would need trusses?, SIPs alone can be used for your home. But engineer Alex Spyrouis well versed in all types of SIP construction and licensed in Arizona, can help you |
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| Chris Kavala<br>[email protected]<br>1-877-321-SIPS<br /> |
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mjmeno
New Member
Posts:5
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| 14 Apr 2013 01:51 PM |
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Thanks Chris.
I figured it'd be a truss roof for two reasons: it's a flat roof design, and I liked the flexibility of being able to run utilities through the trusses. We don't plan on a lot of recessed lighting, but there is some, and from what I understand that's not advisable with a SIP roof. If it's better and more economical to do SIPs all the way around then I'll have to revisit that decision.
Thanks for Alex's contact info. I'll definitely contact him. Sounds like he can set me straight on the roof decision.
I am assuming that working with a traditional stick builder and requesting that they "learn" SIPs on this project is not a good idea -- is that the general consensus here? There's a lot of info indicating an enterprising homeowner could DIY a SIP project, but I would think that most established builders (even small ones) want to do things the way they've always done.
Thanks again,
Michael |
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Alton
Veteran Member
Posts:2164
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| 14 Apr 2013 02:44 PM |
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What type of SIPs do you plan to use? OSB or metal skin and EPS or polyurethane cores? Just curious.
A false ceiling below the SIPs can be as deep as needed to provide space for utilities and recessed light. It will also provide a conditioned space for HVAC which will make it more efficient in your climate.
Certain types of false ceilings will allow future access to utilities. Drywall will also but will need repair after the access. |
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Residential Designer &
Construction Technology Consultant -- E-mail: Alton at Auburn dot Edu Use email format with @ and period .
334 826-3979 |
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mjmeno
New Member
Posts:5
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| 14 Apr 2013 07:30 PM |
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I was thinking OSB/EPS, from Premier. The reason, though, is that when I originally started the research I liked the fact that they had a factory in Phoenix. I have since found out that their factory here closed and I'd have to pay to have SIPs delivered from a plant in CA, so that discriminator is really no longer there. Are there factors I should take into consideration for my location (hot and dry) that would lead me to other SIP materials?
The other thing with Premier was that I also liked the fact the all their engineering drawings were easily accessible online so I could look at things like maximum spans, which leads to the topic of the roof...
The biggest room in this house is 36x32. I am not sure if a SIP roof could span that (the 36' length) without a beam (glulam or similar) across the middle of the span, but it seemed that I was right on the edge of requiring such support.
I am trying to keep things economical, but also considering costs over the life of the home (not just at build time). It sounds like the choices come down to SIPs+beam+false ceiling or trusses+spray foam. I like the idea of the design simplicity and fewer contractors required with the all-SIP solution, but I'm currently ignorant on how to compare the other qualities of the two options.
Thanks for the help! |
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Alton
Veteran Member
Posts:2164
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| 14 Apr 2013 09:35 PM |
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I do not know of any SIP that can span 36' without some kind of support. If you do not use SIPs, then you might want to consider a truss roof with the insulation above the trusses so that the trusses would also be insulated. With trusses you would not need a SIP with skins on both sides. See http://www.atlasroofing.com/tabbed.php?section_url=58 Spray foam could be added between the trusses to increase the R-value. Another way to span 36' would be with engineered floor trusses. If the roof load is great enough, a hiden beam could be installed in the 4x2 floor trusses that would not extend below the ceiling. When you say "flat roof" I am guessing that the roof would slope at least 1/2" per foot. Do you plan to install a standing seam metal roof? Kingspan in Deland, FL has metal SIPs that will look like a standing seam roof. http://www.kingspanpanels.us/ But the SIP will require support probably every 4'. |
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Residential Designer &
Construction Technology Consultant -- E-mail: Alton at Auburn dot Edu Use email format with @ and period .
334 826-3979 |
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Lbear
Veteran Member
Posts:2740
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| 15 Apr 2013 12:59 AM |
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Don't forget that termites are prevalent in AZ and wood SIPS are NOT resistant to termites, neither is the EPS foam. The foam should be Borate treated, I doubt Premier SIPS treats their EPS with Borates. That's not to say they have a poor product, it's just that they don't treat the foam.
You are kind of defeating the whole purpose of SIPs if you go with a wood truss roof. With SIP roofs you don't have to vent and it is a condition space. When you design a home it should have a first floor mechanical room, that is where you can stick the air handlers, keep them in a conditioned space and out of an unconditioned attic.
I am a fan of metal SIPs and my design is an ICF wall and a metal SIP roof. I prefer concrete and steel for my walls/roof over wood. Although AZ is dry, one can still have issues with rot/moisture during monsoon season (June - October) and termites are always a problem. I've seen Phoenix walls suffer extensive mold issues right after that 4 month humid and miserable time of year known as the Phx Monsoon Season. Nothing like 110F, high humidity, and those nasty dust storms/haboobs that we now get, at least 2 per week during monsoon season.
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mjmeno
New Member
Posts:5
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| 15 Apr 2013 02:19 AM |
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Thanks all for the great questions and suggestions. Let me attempt to provide some clarification. The roof is not truly flat -- a bad generalization on my part. It will be sloped for runoff, and there will be parapet walls and scuppers all around -- so no standing seam roof (although I love the look -- it's not allowed by the HOA). If the truss design is used, the SIP walls that are parallel to the trusses will go all the way up, creating their own parapet. The SIPs that are perpendicular to the trusses will need to have parapets stick-framed. If you do not use SIPs, then you might want to consider a truss roof with the insulation above the trusses so that the trusses would also be insulated. With trusses you would not need a SIP with skins on both sides. See http://www.atlasroofing.com/tabbed.php?section_url=58 Spray foam could be added between the trusses to increase the R-value.
This is very interesting. I had been thinking that it'd be a truss roof topped with truly flat OSB, then some kind of ripped strips (sleepers?), then more OSB to create the required pitch, then a spray foam roof. Spray foam insulation would then be applied to the underside of the OSB and trusses to the desired thickness. I was told that the air gap would be nothing to worry about, but the last thing I want is any moisture getting in there creating the dreaded "oatmeal" OSB. The trusses would be conditioned space -- something I want for the HVAC. There is indeed a utility room in the conditioned space as well. These comments do, however, make me realize that that there is a potential for thermal bridging through the trusses since the roof insulation would be around them, not between them and the roof. The idea of single-skinned SIP panel plus trusses is interesting but at that point I would imagine it'd be better to just go 100% SIP with a false ceiling and a beam (or two). I think I am going to revisit that option. I shouldn't have dismissed it so quickly. Alton, I would imagine that the trusses would end up behaving a lot like floor trusses and would basically be shaped the same. I believe it's called a parallel chord truss. I'm looking forward to talking in more detail with a structural engineer about it to see if that really is an option that can span such a long distance. Just did some research to even find the name of the truss and a few other forum posts indicate that they can be pretty pricey and still require beams for long spans -- another indicator that the SIP roof may still be the better option. Lbear, your point about termites is well put. We've had several friends battle them and one Realtor friend mentioned there are only two kinds of houses in Phoenix: those with termites and those that will have termites in the future. I'd put that as a big plus for metal SIPs that I had forgotten about. You're also right about those monsoons. It doesn't rain often, but "when it rains, it pours" ;-) -- I just looked it up on Premier's site, and they do say "the foam in Premier SIPs includes a treatment that makes the foam resistant to carpenter ants and termites" however I will still take this under consideration. I am in no way sold on any one design, technology, or supplier. Thanks again everybody. |
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Alton
Veteran Member
Posts:2164
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| 15 Apr 2013 11:57 AM |
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Trying to accomplish what you are for your area, my preference would be for metal skin SIPs for walls and roof. If you do not want to leave the metal exposed for the inside, then use metal hat channels to furr out the walls to create a chase for utilities. Also consider using paperless drywall to defeat termites. Ideally, the only wood in the house would be beams supporting the roof and trim around the doors and windows. At least by using wood only where it is visible and easily inspected, you should stay ahead of termites.
The exterior wall's metal skin could be covered with synthetic stucco if metal is not allowed by covenants. Chris Kavala could walk you through how the stucco can be applied.
One has to very careful when the application calls for the roof not to totally cap a wall. I mention this because if the roof truss is above the roof to form a parapet wall, leaks could result when the flashing goes. |
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Residential Designer &
Construction Technology Consultant -- E-mail: Alton at Auburn dot Edu Use email format with @ and period .
334 826-3979 |
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arkie6
Veteran Member
Posts:1453
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| 15 Apr 2013 01:50 PM |
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Have you considered a high mass wall such as ICF or similar construction? The climate in Phoenix is ideally suited to this type of construction. And your exterior of stucco or synthetic stucco can be directly applied to the ICF foam. |
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Alton
Veteran Member
Posts:2164
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| 15 Apr 2013 03:17 PM |
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If shotcreters are available in the Phoenix area, then consider using shotcrete panels for the walls and roof. The thickness of the EPS and double wythes of concrete can be sized for your climate. The EPS would be well protected from insects by being in the middle of the wall. With the EPS in the middle, the wythe of concrete inside the house would help average out the daily temperature swings. Mass works the best when there are large temperature swings on a daily basis above and below the desired set point. |
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Residential Designer &
Construction Technology Consultant -- E-mail: Alton at Auburn dot Edu Use email format with @ and period .
334 826-3979 |
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Lbear
Veteran Member
Posts:2740
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| 16 Apr 2013 01:41 AM |
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Posted By Alton on 15 Apr 2013 03:17 PM
If shorcreters are available in the Phoenix area, then consider using shotcrete panels for the walls and roof. The thickness of the EPS and double wythes of concrete can be sized for your climate. The EPS would be well protected from insects by being in the middle of the wall. With the EPS in the middle, the wythe of concrete inside the house would help average out the daily temperature swings. Mass works the best when there are large temperature swings on a daily basis above and below the desired set point.
Alton, No shotcrete out here except for the State Highway Division (highway overpass erosion control) and pool companies. There was a private home building shotcrete/SCIPs company out here but from what I heard they have gone belly up. Outdoor concrete work from June - October is risky business in Phoenix. Unless the concrete is protected from the sun and elements, it's a difficult job. The summer heat 115F+ (that's in the shade, add another 20F+ for direct sun) and a 40mph+ monsoon wind have destroyed many sidewalk and driveway pours. The moisture gets sucked out of the concrete so fast that it's not recommended to do exposed concrete during those months. I've seen contractors try and do house slabs but they have to constantly run a hose over it and cover it, even then, poor curing leads to weak and cracked slabs. Sometimes they try and pour the slabs around 10PM but the pumping companies charge double overtime for nighttime work. It's actually been deemed so deadly & dangerous to do highway roadwork during daytime hours in Phx, so the road workers only work from 9PM - 6AM. One thing about ICF is that is provides a protected and perfect curing environment. I wonder if the humidity of the S/E is why SCIPs is more popular in that part of the country? Moderately humid air is better than 5% humidity with 115F temps, when it comes to exposed concrete curing. |
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Lbear
Veteran Member
Posts:2740
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| 16 Apr 2013 01:46 AM |
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Posted By mjmeno on 15 Apr 2013 02:19 AM
Lbear, your point about termites is well put. We've had several friends battle them and one Realtor friend mentioned there are only two kinds of houses in Phoenix: those with termites and those that will have termites in the future. I'd put that as a big plus for metal SIPs that I had forgotten about. You're also right about those monsoons. It doesn't rain often, but "when it rains, it pours" ;-) -- I just looked it up on Premier's site, and they do say "the foam in Premier SIPs includes a treatment that makes the foam resistant to carpenter ants and termites" however I will still take this under consideration. I am in no way sold on any one design, technology, or supplier.
Thanks again everybody.
Interesting. I would call Premier to verify that they do treat with Borates. As long as you catch the termites early, it's not too bad but it is a constant battle and expensive headache. |
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mjmeno
New Member
Posts:5
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| 16 Apr 2013 10:45 AM |
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Thanks again everybody. Yesterday I was able to talk to a number of professionals about my project, and based on arkie6's suggestion, research ICFs. I don't know why I had dismissed ICFs in my early research -- I guess I fell in love with SIPs early on.
A big factor for me was availability of local suppliers and expertise. I never really found any with SIPs in this area, but I did find a number that work with ICFs. I'm taking that as a strong indicator that ICFs are probably the more appropriate product for Phoenix's climate and pests. The foam on the outside also seems to make better sense for stucco application. I'm sure that metal SIPs would be a nice product as well (also avoids wood), but it seems for my exact use and considering local availability, I think I am going to switch my plans to consider ICFs more. There are multiple ICF builders and at least one ICF manufacturer that I've already found locally.
The other thing that was interesting is that three pros have now recommended the truss roof over a SIP roof for my particular application (big spans, santa fe style "flat" roof with parapets). Apparently the trusses can be ordered to have the bottom chord flat and the top chord gently sloped so that nothing else is needed to create the slope. Both ICF and SIP folks use SIP roofs on the vast majority of projects, but for this particular installation it seems a SIP roof may not be the right choice.
Lbear -- great points about summer pours in PHX. I've seen them work through the night as well, but it's probably wise for me to delay the pours project until October/November. At my speed, six months of planning is probably about right anyway. My site does have a slight slope into a wash so I wouldn't be surprised to see 1-2 months of work before the first pour anyway.
SCIPs also sound really interesting! I did design and GC my swimming pool so I had some firsthand shotcrete experience. I've never seen it used for houses though. Certainly interesting. I'm continually amazed at the various building technologies in use.
Time to start updating my plans from ~6 inch walls to ~11 and see what it looks like...
A huge thanks again to all those that have provided info and questions. It's *greatly* appreciated.
Michael |
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jonr
Senior Member
Posts:5341
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| 16 Apr 2013 01:11 PM |
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Best idea I've heard for exposed concrete is to keep a sprinkler on it. Perhaps with a timer (to reduce water use). |
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cmkavala
Veteran Member
Posts:4327
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| 16 Apr 2013 01:57 PM |
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Posted By jonr on 16 Apr 2013 01:11 PM
Best idea I've heard for exposed concrete is to keep a sprinkler on it. Perhaps with a timer (to reduce water use).
jonr, best to keep the water running for at least 3 days straight, if water is concern then a curing compound can be rolled /sprayed on immediately to contain moisture in slab |
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| Chris Kavala<br>[email protected]<br>1-877-321-SIPS<br /> |
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jonr
Senior Member
Posts:5341
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| 16 Apr 2013 02:15 PM |
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Agreed, I was thinking of a 5 minutes on, 10 min off, repeat endlessly type of timer. |
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Lbear
Veteran Member
Posts:2740
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| 16 Apr 2013 03:14 PM |
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During summer the water in a garden hose sitting in the Phx sun gets SO HOT that if you turn on the faucet the water coming out can give you 3rd degree burns. I kid you not.
When you turn on the COLD water inside of a home during summer, the water will always be warm, as the water lines are only buried 6" under ground and they sit inside of the hot poorly insulated walls of the home. When you run the clothes washer you don't need the heated/warm water supply line, just leave it on cold and the water will come out warm.
If you park your car outside and leave it in the sun, the interior can reach temps of 200F (thank you solar heat gain) and the steering wheel can get so hot that you can burn your hand. People will wear gloves during summer so that they can touch the door handle and steering wheel.
Our car tire life is about 1/3 of what it is in moderate climates. The pavement gets so hot and the tires get attacked by UV and insane heat, that the tires begin to fall apart very quickly. In summer people will have blow outs all over the highways. They recommend airing the tires 5-10 pounds more than normal. An under inflated tire is very dangerous while slightly over inflating keeps the tire cooler. For instance, if the tire max psi is 50, I will run it around 37 cold/42 hot.
It's pretty crazy what happens out here in the summer...
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Alton
Veteran Member
Posts:2164
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| 16 Apr 2013 05:08 PM |
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Lbear,
Why does anyone live there? Come visit me in the southeast and enjoy our humidity. |
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Residential Designer &
Construction Technology Consultant -- E-mail: Alton at Auburn dot Edu Use email format with @ and period .
334 826-3979 |
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Lbear
Veteran Member
Posts:2740
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| 16 Apr 2013 07:01 PM |
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Posted By Alton on 16 Apr 2013 05:08 PM
Lbear,
Why does anyone live there? Come visit me in the southeast and enjoy our humidity.
Good question. I dont plan on living in Phx much longer. I hope to move to Northern AZ and build up there. Much more moderate at 4,800 feet although its still high desert but much more tolerable and you get a 4 season climate. |
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