SIP Construction Once Again

I am on the board of our local Habitat for Humanity.  We have not built a home in three years due to - you got it - COIVD.  We are now ready to start building again and have been looking at SIP construction due to the speed of construction, energy efficiency, and earthquake resistence.  We will be using a perimeter concrete foundation (about 24" above grade) with a glulam ridge beam and center floor support.  The building will be 42' x 28'.

At this point, we considering using the floor, wall and roof system from a company in Puyallup, WA, who have been in business for 50 years.  Their panels are 7/16” OSB on each side bonded to the foam.  The floor and roof systems also have 7/16” OSB cladding, but have embedded structural I-beams for strength.  OSB is treated with Boron to stop termites and mold.

For our last couple of homes we have built, we have used Tyvek building wrap under Hardieplank-type lap siding (we also did T1-11 on a couple of homes years ago).  For the roof, we have installed 40lb building felt and 3-tab comp roofing.  In far Northwest California, we get 90+ inches of rain; keeping the water out is high on the list of priorities.

We are all volunteers.  We know traditional framing, but cannot start the build until next spring if following traditional methods because of weather.  With SIP panels, we could be weather tight before the rain really starts this year.  The big issus is that we don't want to put a family in a home that will not be durable.  Our first home was built in 1999 and still looks great - we want a SIP home we build to still look great  in 2045...

Anyone with SIP construction experience please chime in.

Thanks

We have a local company(and along the Gulf coast) that does steel and aluminum faced panels. 

https://structall.com/

I watched as a crew of 4 guys built a 2 story home in Treasure Island, Fl. They took their time and had it dried in in about a week. Then they cut the holes for all the windows and doors...

I forget the sqft but it was going to need a 2 ton AC unit and the whole envelope came in at R-52. Its like snapping together a walk in freezer.

I'm using their panels on an addition to one of my properties in Florida and will probably use them to build some shop space up in Ohio.

Here is the house I saw being built.

https://www.google.com/maps/place/9800+Harrell+Ave,+Treasure+Island,+FL+33706/@27.7568106,-82.7658299,17z/data=!3m1!4b1!4m5!3m4!1s0x88c2fd6cf017b42d:0x5c74f20c94015f5c!8m2!3d27.7568059!4d-82.7636412

About 10 or 15 years ago my next door neighbor built a 3+ stall garage, with a second story for his wife's art studio, using SIPs.  It went together in about a day, they used a crane to lift and install the panels.  It's a very solid building, well insulated and very quiet inside.  If I were to ever build a new house they are what I'd use.

FrenchyD used SIPS when he built his house and can't say enough about them, I'm sure he'll chime in when he sees this discussion.

Amen.  They are wonderful!!!
   But  I can't agree that they are all that fast.      The issue is the splines that connect them. Any minor dent or damage to the OSB doesn't allow the spline to just slide in and then you have to get clever to completely snug them together.  I was also given an adhesive to effectively " glue"  them and act like a gasket at each joint.  Since I was often working alone and through the dead of winter (-40f) I'd have to heat the adhesive and get the splines together before the adhesive got too stiff and cold. 
      Having said all that they are wonderfully efficient at retaining heat in the winter and keeping the house cool during 90+ degree days in the summer.  Sun coming through the windows is often enough to heat the house comfortably during the day and my heating bill is significantly lower than my neighbors with conventional construction. 
  During the summer the house remains cool inside even when temps are in the 80's. Then 3 small window units keep a 5500 sq ft house  chilly when temps are over 100 
      
     If speed is a priority I would use ICF's for the walls and SIPs for the roof. Talk about simple. ICF's Put together like big foam Lego's and just about as quick. Drop in Rebar as you go.  A typical house could set the forms up in a day with a small crew of untrained people

   Then turn the wiring and plumbing over to that crew.
    . Pump the concrete in the next morning and put the roof on from there.  
    The exterior can be dealt with nearly any way, stucco, brick,  or clapboards,  and the interior can just use sheet rock or stucco again on the interior. 
     

Awesome product but susceptible to some pretty dire problems if assembled poorly. My gut reaction is SIP is not a great system for volunteers. 

https://youtu.be/ZtiJk1mvxMs

..also Google "SIP ridge rot"

OHSCrifle said:

Awesome product but susceptible to some pretty dire problems if assembled poorly. My gut reaction is SIP is not a great system for volunteers. 

https://youtu.be/ZtiJk1mvxMs

..also Google "SIP ridge rot"

That is why I steered away from OSB, hate the stuff.

Structal has metal skins and they snap together hard with a click.

If installed properly it sure saves energy.   

In reply to jgrewe :

Note:  That video was NOT an OSB fail. It was a building envelope vapor barrier fail. Any wood product skin would have rotted and failed. 
 

I just took apart a building that was sheathed with 3/4" plywood on the walls. It rotted and failed due to water intrusion too. 
 

OSB is an excellent material, and in some aspects can outperform plywood. 
 

SIPs panel strength is dependent on the adhesive, and the interaction between the different laminations.  Great product, but a water intrusion issue can break the adhesive bond, and cause panel failure. Repairs are extremely difficult and expensive.
 

My only concern with SIPs in this application is your climate, and the inexperience of the volunteers in doing the waterproofing. (I spent 10 years full time leading volunteer crews for HfH). 
 

If you have a specific team trained in the waterproofing, it can be done well by volunteers. But that assumes they are a committed crew that takes the time to learn the processes, and is careful in the application.  That's a tall order for volunteer crews.   Random crew members showing up when they have some spare time lending a hand now and then is a no-no.

I have done SIPs with HfH volunteer crews. And I have seen failure. 
 

I'd be comfortable doing it, but I'd want the crew trained well, and led by a careful competent person. 
 

I would also hire a third party inspector to inspect the integrity of the vapor barrier installation before closing it up and making it inaccessible. 
 

Consider a commercial waterproofing system. Tyvek is a terrible idea.  The commercial systems are too expensive to typically be used in residential work, but you may be able to get donations that make it worth consideration. 

SV reX said:

I have done SIPs with HfH volunteer crews. And I have seen failure. 
 

I'd be comfortable doing it, but I'd want the crew trained well, and led by a careful competent person. 
 

I would also hire a third party inspector to inspect the integrity of the vapor barrier installation before closing it up and making it inaccessible. 
 

Consider a commercial waterproofing system. Tyvek is a terrible idea.  The commercial systems are too expensive to typically be used in residential work, but you may be able to get donations that make it worth consideration. 

So what systems are you referring to?  We don't have any industry here - a supermax prison (Pelican Bay) and Redwood National and State Parks.  If not Tyvek, then....?

In reply to CJ :

Since the concerns are both water intrusion from the outside, AND moisture from the inside condensating and not being able to dry, I would definitely have an in-depth conversation with your panel manufacturer about their recommendations for waterproofing and water vapor transmission and specific details for installation before beginning.  Make sure they are willing to provide detailing and that they are willing to warranty the job. 
 

I'm not knowledgeable about your specific climate, so I am hesitant to provide specific instructions. 
 

SIPs panels can make a very tight building, and vapor transmission in a cold damp climate is a very legitimate concern.   Ultimately, you don't want the dew point to be inside a wall.  That means controlling the water vapor before it gets to the wall (from both sides), and also having the envelope breathable enough for drying. 

In reply to CJ :

I suspect a water barrier from an EIFs manufacturer would do great, but you really should go with the recommendations of the SIPs manufacturer. 

Another option to consider...

Since your real issue is not insulation, but trying to "beat" the rainy season, have you considered light gauge metal framing?

The techniques are similar enough to wood framing that anyone familiar with traditional framing could easily switch, and the product won't be harmed by the rain. You won't get the same speed, but if you don't beat the rain, it won't harm the building. 
 

There are several systems out there. It's been a long time since I built a residential metal stud building, but I'll bet the costs are similar to SIPs. 
 

And it's still a new skill everyone can have fun learning. (When I built a few with Habitat for Humanity International, they had fantastic buzz. Everyone was interested in the steel houses.  At least one of them was donated entirely, just so the company could get some exposure)

In reply to SV reX :

Thanks for another option.  I will have to check and see if there is a vendor somewhere near us.

In reply to CJ :

I love metal studs but unfortunately they are about 4x-6x more expensive than wood, typically.

They are easy to get nice and straight and square, though.

[edit]  You will also need continuous insulation outside the sheathing if you go the metal stud route.  How much depends on where you're located.

In reply to Duke :

I agree they are typically more expensive than wood. 
 

But residential applications are cheaper than commercial, prices are fluctuating wildly, and SIPs are expensive (so they might be in the same ballpark)

Figured it was worth looking into. 

The reason I love the SIP's is the energy savings.  Neighbors with 2x6 construction and fiberglass insulation are spending 3 times what I do  for heat in the winter.  They all have new high efficiency furnace's and mine is close to 30 years old.  
     One neighbor pulled all the fiberglass insulation  and had foam sprayed in.  He reported last year his bill was only twice as large as mine.  
   My wife is a diabetic so she's freezing in the winter unless the temps are 75 or above. .   I sleep without blankets and no T shirt because I'm sweating. I'd like to see what the bill would be if I turned it down to the 70  I prefer. 

SV reX said:

In reply to Duke :

I agree they are typically more expensive than wood.

But residential applications are cheaper than commercial, prices are fluctuating wildly, and SIPs are expensive (so they might be in the same ballpark)

Figured it was worth looking into. 

Absolutely is worth looking into, especially compared to SIPs rather than wood stick framing.

[edit]  Sorry, Paul, I wasn't trying to second guess you this time.  I love metal stud construction; it just has some other criteria to be aware of.

In reply to Duke :

No problem. You are absolutely correct. 
 

It's not an apples to apples comparison. You have to think about different stuff. 
 

Thermal bridging is the big one with metal. 

So about the environment...

The lot is less than a mile from the Pacific.

Winter temps here are low 40s to mid 50s.  Few days into the low 30s.  An inch of snow every 3-4 years.  Where the lot is gets around 50" of rain a year.  Winter storms may bring 40 - 50 mph winds.

Summer temps are high 50s into the 70s or low 80s.  Ocean effect fog when it gets hot inland.

We have been known to have an earthquake.

Our downtown was erased by the tsunami from the 9.2 Alaskan earthquake in 1964.  Our harbor was erased by the tsunami from the Japanese (Fukushima) earthquake in 2011.

In reply to CJ :

I guess I worded that badly. I should have said I'm not knowledgeable about building in your specific climate.  
 

I'm just not experienced in it.  That's why you need local input from building professionals and the SIPs manufacturer. 

CJ said:

So about the environment...

The lot is less than a mile from the Pacific.

Winter temps here are low 40s to mid 50s.  Few days into the low 30s.  An inch of snow every 3-4 years.  Where the lot is gets around 50" of rain a year.  Winter storms may bring 40 - 50 mph winds.

Summer temps are high 50s into the 70s or low 80s.  Ocean effect fog when it gets hot inland.

We have been known to have an earthquake.

Our downtown was erased by the tsunami from the 9.2 Alaskan earthquake in 1964.  Our harbor was erased by the tsunami from the Japanese (Fukushima) earthquake in 2011.

There are still benefits to SIPs. But care will be needed with vapor and moisture. 
   A SIP is supposed to  be 200% as strong as a stick built house so earthquakes and  other shaking forces won't impact it as much.  
    Plus the fire resistance.  Fiberglass insulation allows free access  to air. There are three parts of fire oxygen, fuel,  and heat. Sheetrock protects the SIP from fire on the inside. By eliminating the oxygen it's far more resistant to fire.  
     In addition every SIP I've seen and worked with is straight.   So much so that my southern wall which was bowed by over 3/4 of an inch due to Timbers warping. Was pulled plumb line straight in only a year. 

In reply to frenchyd :

Kinda true. 
 

SIPs are more resistant to compressive loads and lateral loads. That DOES NOT mean they are more resistant to earthquakes. Shaking forces often need flexibility, not rigidity. No one should make earthquake claims except a structural engineer who has done the calculations on a specific structure. 
 

SIPs panels are more resistant to burning, but get poor ratings from fire prevention professionals because they are more prone to total building collapse than stick built buildings. Basically, a stick built building is predictable in a fire. It burns in a predictable manner slowly. SIPs buildings heat until there is substantial compromise to the panel integrity, then the entire building collapses without warning. Firefighters hate SIPs.

Those are two claims made by SIPs manufacturers which are not entirely true.

CJ said:

Winter temps here are low 40s to mid 50s.  Few days into the low 30s.  Summer temps are high 50s into the 70s or low 80s. 

In that case, energy efficiency isn't as big a factor as it would be for building in more extreme climates (like Minnesota, where Frenchyd and I live.)

SV reX said:

In reply to frenchyd :

Kinda true. 
 

SIPs are more resistant to compressive loads and lateral loads. That DOES NOT mean they are more resistant to earthquakes. Shaking forces often need flexibility, not rigidity. No one should make earthquake claims except a structural engineer who has done the calculations on a specific structure. 
 

SIPs panels are more resistant to burning, but get poor ratings from fire avoidance professionals because they are more prone to total building collapse than stick built buildings. Basically, a stick built building is predictable in a fire. It burns in a predictable manner slowly. SIPs building heat until there is substantial compromise to the panel integrity, then the entire building collapses without warning. Firefighters hate SIPs.

Those are two claims made by SIPs manufacturers which are not entirely true.

I'll give you a partial on that.  I built mine for a double timber frame.  Hardwood Timbers because of their durable nature in a fire.   
  I was convinced of that because of a giant  fire in an old wooden warehouse over in St Paul.  The fire burned off the exterior wood  and then the fire dept got the fire out.  After inspection by the state the Timbers were approved to remain in place.   The worst case the fire only cost 1/2 inch of  char.  The owners sand blasted the Timbers and  converted it to apartments.  
 

The earth quake issue I believe a SIP residential home would survive longer than a stick built home.  The reason is much less localized loads    Between the adhesive and the multitude of nails at the joints rather than typical just 2 nails into the top of a 2x.   
      I see how easily a stick built house can be knocked over and tossed into a dumpster  and I believe  the SIP's would be far more resistant.  Since my SIPs are clamped between two Hardwood Timbers that are actually bolted together I feel whoever has to take this building down is in for the fight of their life