Replies

1. 
   OrchidGuy | May 31, 2004 03:44am | #1

   From watching "This Old House", I would try the poly- icinyne foam that they seem fond of using.As far as my insulation experience goes the 2 occasions that I did install it, I used fiberglass batts with a poly vapor barrier.

1. 
   fdampier5 | May 31, 2004 04:46am | #3

   Fiberglas bats have two real weaknesses.  first if it gets wet it's r value disappears second the colder it gets the worse it's R value is.  great at 70 degrees ok at 32 but 40 below it's almost like it's not there..

     Can't get foam wet, (well the inside of it )! keep it under water and it's r value stays the same..   And it's R value isn't temperature dependant.. 

1. 
   OrchidGuy | May 31, 2004 05:03am | #4

   Well, installing the batts wasn't my idea or project, so I don't have to deal with the moisture problems. As for r value, I live in southern N.Y. state. It has never gotten down to 40 below, but then O is cold enough.I tried convincing these 2 gentlemen, but they felt hiring a foam insulation guy was to much money and hassel with installing it. Besides the majority of my experience was in custom cabinetmaking and trim carpentry. My experience with insulation is severly limited. I only know what I've read about insulating in FHB.

   Edited 5/30/2004 10:11 pm ET by f4phanatic

1. 
   fdampier5 | May 31, 2004 04:21pm | #7

   I forget that there are parts of the country that aren't as cold as Minnesota, I know they get more snow and blizards in parts of New York because I hear about Buffalo all of the time  about how many inches of snow they get.  But maybe southern New York is much warmer.  I do know that energy costs are much higher in New York than in Minnesota so maybe they offset one another..

         I guess you could do a chart to see where the break even point is and if you plan on living in that home less than the break even point is you build with cheap insulation..

1. 
   OrchidGuy | Jun 01, 2004 09:10am | #12

   I haven't been to Minnesota, and I know a lot of New Yorkers probably coundn't survive the winter there, but I've been to Buffalo quite a few times, and, I know all about the snow storms they get. What we consider a blizzard in New York City and the surrounding suburbs, the Buffalonians would call a light dusting! As for the winters in southern New York, when the night time low gets down to 0, that is considered cold. Mostly our winters are mild, and the snow that does accumlate usually melts within a week or two, then it snows again. Our average amounts during a storm are about 4 to 8 inches. As for energy costs you want sticker shock, we invented it! The state legislature levies, get this, 3 different taxes on gasoline! As for insulation with batts, I've only done it twice, and they were on remodel/ rennovation projects on someone else's home. The method of insulation around here is traditionally left to local trade practices by contractors. Some use fiberglass while others use spray on foam. I haven't seen any SIPs being used, could it be local tradition! Anyway I have been pondering some thoughts about SIPs:

   1. Could they be used on an existing stick frame building?

   2. I've seen SIPs being installed once on This Old House, I noticed that the manufacturer used OSB for the sheathing. If it rains after the panels are installed the OSB would swell, as OSB is famous for, would that be a problem when you started installing the exterior finishes?

   3. I noticed that they were lifting the panels with a crane, and the crew installing them had attached a piece of 2x lumber with screws or lag bolts to the panel on the face of the OSB. Do they fill those holes in after installation, and if they don't would any moisture be a problem entering the core of the panel?

   I've recently purchased a book a book by Tedd Benson on Timberframe Construction and the is a chapter on insulation and exterior sheathing, with SIPs and more traditional methods. Now that my schedule is winding to a more subdued level I'll see what he has written about SIPs.

2. 
   fdampier5 | Jun 02, 2004 05:11am | #13

   Any new method of construction has it's incubation period.. I can imagine when they first invented stick building instead of the previous timberframe how long it took to catch on. 

     My research indicates it was well over 150 years before stick building became predominate.. (and that's a light superficail glance at best)

     Thus SIPs will become the dominate construction technique sometime around 2100.

     Why would you build awith SIPs and then build with sticks.  SIPs by themselves are about 200% stronger than stick built.  Thus adding stick building to a house will offer little.

      Perhaps you think that only timberframe homes can be built using SIPs?  Not true.  stand alone SIP built houses can and do exist. In fact commercial buildings have been built for over 50 years to my knowledge.

     Yes lifting panels in place with a crane is common where ease and speed of building is important.  The screw holes will have zero effect.. Water won't penatrate the foam and thus should have zero further effect.  I haven't noticed any swelling in any of the panels I put up over two years ago. The panels have been exposed to all sorts of weather with little or no protection and the factory informed me that was OK to do..

      I do notice the panels that have been exposed to weather for that period are turning grey  but a nail will hold as well today as the first day I put them in place.  Nothing has gotten mushy or started to come apart..

     Do remeber that most of what Ted benson wrote about timberframing is at least twenty plus years old.. Not that I dispute anything he says but several improvements have occured to SIP panels  since his books were written. 

     The addition of Borate for example has eliminated the problem of ant infestation that some of the earlier panels experianced.  In addition the industry has matured and the methods of construction improved to whereback yard assembly is no longer pratical.  Thus panels  do not suffer from some of the shoddy assembly techniques suffered in the late 60's early 70's

2. 
   Piffin | May 31, 2004 05:12am | #5

   wEt r-value

   That depends on the type of foam 

    

   Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!

1. 
   fdampier5 | May 31, 2004 04:14pm | #6

   That's intrigueing, who would use a foam  that is affected by moisture to insulate a home? 

3. 
   CloudHidden | May 31, 2004 04:51pm | #8

   >Fiberglas bats have two real weaknesses.

   Three. It's not an air-infiltration barrier, which for hvac is probably the largest part of the battle.

   >Can't get foam wet, (well the inside of it )! keep it under water and it's r value stays the same..

   Well, it kinda can. It can be a water barrier and yet not be a vapor barrier. Both open and closed cell foams have a perm rating and are subject to the diffusion of water vapor, depending on interior v exterior temps, humidity, and pressure. The effect it has depends on the other building materials used, etc.

1. 
   fdampier5 | Jun 01, 2004 12:07am | #11

   I stand corrected..

2. 
   fdampier5 | May 31, 2004 04:41am | #2

   My sister built her house that way and I built mine with SIPs

      She gains much of the strength back that stick building loses over SIPs , almost as fast to build as with SIPs except her costs for materials were dramatically higher than mine..

     Since it's similar to what most houses are built with you'll find a lot of builders willing to do it..

     Weakness of the stick built with foam, 

       First, every 16 inches you'll have a thermal bridge that is at least an inch and a half wide.  It's r value will be 2  !  Go look at a house that is framed up but before they put the sheetrock on. see all those spots where boards are doubled up and more?  There isn't any insulation there is there?  now look at a SIP house!  Insulation all the way around..  walls and roof!  Very few thermal bridges..

        Second,

     cost.    It takes much more to buy the 2x4's and wall sheathing, and blow in insulation  than it does to buy a panel and set it in place.. (about $3.50 a sq.ft. as of  friday) for a 6inch thick panel that can be 4 foot by 28 foot long.  (for ease of handling, I have them no more than 12 feet long since I need to carry them around to the front by hand and I'm fat and old so lighter is better than longer..)  use a forklift and they are a piece of cake!

    the 10 inch roof panels are a little more expensive they were $4.33 cents per sq.ft.

     OK assume that you are building a 40x50 one story house and you are only concerned about the walls and roof insulation..

        $13,700 and you could put them all up in a day..

     Now stick build the same thing and compare costs..(don't forget to add the insulation costs in)

     I wonder how much faster they could sheet rock it since they no longer need to worry about hitting studs  I wonder how much less scarp sheetrock there will be since landing on a stud won't matter.

      Now you can put your windows anyplace and not worry if a stud is there.

     Pipes and wiring seem to scare so many people but once you watch a SIP being built you'll understand that it's not at all difficult.

    Less hassle than stick built once you adapt to it..

1. 
   gdavis62 | May 31, 2004 05:53pm | #9

   Aren't SIPs bridging at every joint?

1. 
   fdampier5 | Jun 01, 2004 12:06am | #10

   Most aren't, they butt together and there is even a glue that you use to ensure they stay that way.    There are splines that connect each panel but they don't bridge they connect,  Hmm that was clear as mud..

      Let me try again.  The splines slide along side and behind the OSB.   They do fractionally reduce the insulation by their thickness 7/16ths, but don't bridge.   There still is a foam to foam connection at each joint.