Site built SIPs

[Doc]

I am reading Chappells book now, and in the table of contents there is a marker that site built SIPS will be discussed. I guess that would have been part of the workshop or class, as there is no mention of them at all in the book.

I am interested in finding more info than the vendors (manufacturers) are goign to put out on their sites about these pieces. From what I am seeing there is really not that much to them. I don't see why you could not make your own if you thought about it for a minute......

Anybody looked at this idea?

Doc

[Brad_S.]

Doc,
I'm inching ever closer to building my own timberframe and have been giving alot of thought to insulation.
Since I own a sawmill, wood costs are not a big issue with me, I get free sofwood trees from local aborists, so I was planning a stick wall infill against a tongue and groove sheathing as Sobon describes, using 3/4" rather than the 1 1/2" he uses.
In order to make it more effecient, I wondered about using 1 1/2" X 3 1/2" studs in a 5 1/2" cavity and shooting soy expanding foam so it wraps around the back. Was getting ready to ask some TF experts (that would include you, Jim!) and insulation experts if this was technically feasible when I saw exactly this being done on This Old House about 4 episodes ago. A question I have is do I need to use a 5 1/2" cavity or could I use 2 1/2" studs in a 3 1/2" cavity. Given foam's great air infiltration protection, perhaps the extra 2" insulation on the wall would not merit the added expense.
I'll be greatly interested in feedback on Doc's question and the above described method.

[Doc]

I am wanting to know more about what you are describing.

I do not have cable. it was the only way to get my teens to do their homework......so I turned it off. Now I do not have all those wonderful shows anymore.

I have looked at various kinds of expanding foam, and considered doign the wiring inside a shell frame and filling the wall (I assume this is what you are talking about), but the cost of the two part mix is higher than the cost of the foam sheet at the box stores for the volume they cover.

Now if I am looking at the sips correctly they are using tongue and groove, or lap edged osb sheet, and glueing up thick foam sheet insulation to that, and then gluing up sheetrock to the inside portion. Is this correct?

The foam sheet is fairly cheap, sheetrock is cheap, the OSB or tongue and groove 3/4 plywood is not dependign on thickness of the OSB. I don't see where these woudl be that difficult to assemble in a barn to lay up on the house as they were finished. The channel for wiring or plumbing could be cut in the sheet, or the sheet cut in sections withthe piping in it. It is something to think about.

I just kinda felt like I missed something when that section was in the TOC and not in the book.......

Doc

[Jim_Rogers]

First of all a SIP is a structual insulated panel. That means it's strong because it has two sheet of wood on each side of the insulation.
A panel made up of one sheet of wood, some insulation and then some sheet-rock is not a SIP. It is usually called a curtain wall or something like that.
Whatever you do you have to have the proper support at the foundation for these panels. You can hang them on the frame itself, but this is not the best method of installation and will probably void any warranty if not installed properly according to company specs.
As to building your own SIPs, you'll have a tough time working the panels with glue at the right temperature and pressure in a press to make them strong.

It was also reported at a trade show, that panel companies are getting away from shipping panels with sheet-rock already installed. Many reasons why. Some are just the damage during shipping, storing at the site while waiting to be installed, installing, water damage waiting to be installed, water damage from waiting to have the roofing put on. These are just a few of the hazards to buying panels from a company and having them with sheet-rock on them first.

Most of the time, if you're going to do panels and have sheet-rock, then a spacer board is nailed onto the outside of the frame before the panels are installed and then after the roof is water tight the sheet-rock can be installed, and finished off.

If your walls are going to be wood paneling then sometimes these spacer boards are also installed before the panels so that you can slide the dry pine paneling boards in behind the post and other timbers that make up the frame.


Brad_S:
In Jack's house, in the book, where he used 1 1/2" planks was to recreate a type of construction know as a "Plank house". I believe the reason for the planks was to create a strong wall system to prevent racking of the house in the wind, as plywood does in stick building.
If you, or anyone is going to build a wall system to fill with any type insulation, careful consideration has to be taken into how it is installed as the "frame" itself is going to shrink some as it dries and you don't want to have the shell walls pull away from the frame or get crushed by the roof as the frame settles.
All 2x wall systems should be outside of the frame itself to prevent any crushing as the frame shrinks a little.
It was reported at a conference that they saw the plates and sills shrink and the roof panels pull away from the roof rafters some 3/4" because they didn't plan on the shrinkage correctly.
If it's inside the frame then you need to plan a space somewhere, usually at the top of the wall, where there is a gap for some future shrinkage to happen.

Good questions.

Keep thinking and doing more research.

Jim Rogers

[TN_man]

In his one book, Sobon did not seem like he was in favor of these SIPs. If I remember right he commented on why one would build such a strong frame to put some weak panel on it and he was concerned about what you would do if one got damaged some how, how one would replace it. I don't remember his exact wording, so I hope I am not misrepresenting his thought s here. I have also heard that insects and varmits like to live in the foam.
Just some food for thought.

[Doc]

Okay, so we have OSB and foam sheet and OSB. Knowing that OSB is not a perfectly flat surface to start with you could never hope to get perfect adhesion unless you used the two part foam mix and made the foam "in" the panel. This could be done easily enough I suppose. Building a pocket with the top open, and whatever needed to be run inside of it (electrical conduit, water pipe, etc) and filling withthe mixed foam compound.

Lots of questions though, and I would like to see what others have doen without SIPs to their timber frames. I guess this adds even more to my reading list.....I am glad I like to read alot.

Doc

[logman]

I thought about trying to make my own panels for my frame but I went
ahead and bought sips.  I built my foundation like Ted Benson describes
in one of his books using a 2x12 pt sill to support the panels.  I installed
them over a 3/4" spacer to slide my boards behind my frame after
installation.  I didn't get the wire chases, what I did was drill through from
my crawlspace into the space left by the 3/4' spacers just below my subfloor
and routed a channel up to my receptacles and switches.  I checked with
the electrical inspector first.  It doesn't affect the structural capabilities of
the panel unless you cut them  all the way across the panel.  
An alternative to sips is the way Timberpeg encloses their frames.  It's
called wrap and strap.  They have a good drawing of it on their website.
I got my panels from General Panel Corp.  They had the best price that
I could find at the time.  

[Doc]

Personally I don't care for sheetrock. Too many headaches with cracks and settling in this area. I woudl rather do wood and stain or paint, but the lady wants sheetrock....jeez......but I can't win them all.

Will look at the timberpeg method. I am just trying to get around stick framing outside of the timberframe if I can help it. I just don't see a reason to spend the time or money to do all that after having built a solid framework. It somehow doesn't make sense to me why. Besides, I am planning on finishing the outside in stone (I think I just found the answer to my situation)......

Doc

[Jim_Rogers]

Usually in every timber frame home, there are some interior walls. These walls are usually stick built walls and are beside a bent so that they can be used as chase ways for wiring, and plumbing to the second floor.
Building this way, beside the bent, allows for the frame to settle and not crush the interior wall, when the proper gap is left at the top of the wall and hidden with some molding.
These interior walls can be covered with sheet rock, and then painted or wallpapered to satisfy the "woman" of the house and give the house some contrast to all the stained wood (frame and paneling).
Just something to think about as you plan your frame and floor plans.
Jim Rogers

[TexasTimbers]

My wife and I are at the end of our "intitial research" phase (because *research* never really ends it seems) and decided how we are going to get around the stick frame dilemma,  as we too wanted to avoid as much stick frame as possible, even though that's what I do for a living. Remodeling/construction.
I don't know if you've ever stumbled across cordwood masonry (CM) aka stackwall construction, but it appealed to us a great deal. We are in the final stages of gathering the materials to timber frame our 12 x 16 well house (using the plans in the back of the Timber Framing Book by ^{Stewart Elliot} and ^{Eugenie Wallas} - minus the first floor foundation) and infill/wrap the exterior with CM. No exposed timbers on the exterior. I will tell you flat out that CM is labor intensive, and is not for most poeple for that and possibly other reasons. It's slooooowwww going compared to practically any other building method except for maybe .... toothpick structures. Grin.
But for some, like us, who aren't afraid of lots of hard work (if you are considering TFing anyway, what's a little more hard work anyway?) it fit us like a glove. We have free loblolly pine, which is one of the most preferred woods for CM, and we love the way it looks (most of it).
You might say we are a little eccentric so that helps too.
If you've already settled on stone then you don't need to consider it, but dependoing on your situation (CM is MUCH cheaper than stone unless you can get free stone), you might give it a think. Do a google on it. Just beware, some of the experts (some self-appointed)on CM are TRULY eccentric to the point of making me and my lovely bride look like Baptist ministers!
Regards, Kevin.

[Jim_Rogers]

There are many types of infill that can be used.

Cordwood infill is one.....

I beleive I posted some pictures of a small shed I fellow near me did, some time ago.

I sold him the locust logs to make these walls.

It can be very interesting.

Here it is again:




Jim Rogers

[Doc]

I am in North Bama. The land I am looking at purchasing is in the foothills in southern Tenn. tn_Logger, and others here can attest to the amount of "free" stone there is for the picking around here. I could build skyscrapers of the stuff. Personally, I just like the looks, and have been looking at slipforming the exterior walls in stone. We will see how it goes. I still have a long way to go before I get to that point.

Cordwood is cool looking, and I like the way that shed turned out. It woudl appear to have some outstanding visuals from some of the stuff I have found on the net.

I am still trying to get an idea of how big or small to build the thing first. Funny thing is is that I haven't bought the land yet.

I have a plan though, and like everything else I do it will happen in time.

Doc (not to be confused with some of those other Docs I have been reading about here).

[Don P]

As far as making your own panels, some manufacturers were doing basically what you were talking about, glueing sheets together. The glue joint has to be stronger than foam, at least on the surface that doesn't sound too hard. A vacuum bag around the panel layup could deliver uniform clamping force. There was talk at one time about putting borates in foam, I never heard more about it ???

[Doc]

Uniform layup....hmmmmm

Now this is the cheap butt in me thinking here, but I think I have a way to make up uniform clamping force without alot of hardware.

Lay your OSB or playwood on the ground (must be level and flat ground ....concrete). spread out putty type liquid nails with a putty knife in a thin layer (1/8th inch shoudl suffice). Lay foam sheet on top, squaring up with plywood as you lay it down. Lay another sheet of clean plywood on top (no glue), and place a cinderblock in the middle of the top plywood, and add blocks around it working your way out in a circle to the edges.

Cinderblocks weigh what? 10lbs each? more? This shoudl be more than enough clamping force to hold the foam down to the glued plywood till it sets up. Considering the SIPS are not weight bearing structures this shoudl be more than satisfactory for a sheathing material. You could trim down the edges of the foam with a hotknife and rim the plywood in 2x4s or 2x2s and tack them together. This would get you somewhere.

With the glue set up on the one side, start the other the same way withthe now glues plywood side up. this would get you a structure of a homeade sip that shoudl work I woudl think.

One of you or more have worked with sips. You know what they look like, and how they work. Correct what I have just posted and tell me what I am missing here. I am just speculating off the top of my head.

Doc

[Furby]

SIPs are as has been stated, STRUCTURAL Insulated Panels.
You just are not going to get the structural part doing that. SIPs are made (atleast the ones I've seen) with big presses that compress and heat the foam as it cures, creating a more dense and stronger product.

What DonP said makes sense if it applies enough pressure.

I see using sheats of foam board or spraying foam into pre made panels simply as a waste of time in my mind. Why not just put it up in pieces then?
OSB is EXPENSIVE! Why use it if you don't need to?
Last time I checked, liquid nails or the like, does not spread, you will not get and even glue up.

[Doc]

Liquid nails was simply an example (the first thing I could think of since I have been fighting the stuff recently with a house I am remodeling).

I am looking at something other than building a stick frame around the timber frame. It just doesn't make sense to do the stick frame around it, but the cost of prefab SIPS (from the few brochures I have) is prohibitively expensive.

Oh well, back to the drawing board.

Doc

[Furby]

Doc,
Let me explain my view a bit.
SIPs are rigid and solid and are used to span open areas, thus the structural part of things. Now the vertical application such as wall sheathing for a timber frame, does not require they be as structural as in roofs and such. They are still structural due to the fact you have no framing to support them between the timber framing. Say you have an 8' wall span, not a big deal but the amount of wind that will catch is a fair amount and will vary, causing flex. Also things getting bumped or leaned against the wall adds stress the panels must support.
In the case of SIPs, they have been made into/as one unit with pressure applied to increase the density of the foam to improve strength.
Building your own would require you to do the same. An uneven layer of glue, or a weak mix of glue, or even less then idea drying conditions leaves you with a panel that could possibly flex and delaminate over time.
Think of some plywood after it gets wet for a while.
I don't know what the materials cost in your area. Here the regular price for 7/16" OSB is $14.50 x2, 2" foam is $16 x2 or however many. 1 1/2" foam is $14.40, so not a big difference. Glue, plus time cutting channels and gluing up, just sounds like a lot to me.

[Doc]

Compare that cost to the cost of a SIP of the same size though and you will see why I asked about this.

I understand where you are coming from too. I may just have to stop being cheap and just do it. We shall see when I get to that point. I still have the land to get, the barn to put up, the land to grade.......I have a long way to go......

Doc

[JoeyLowe]

I think that Furby is on the right track here.  Structural means just that.  You won't be able to duplicate the process in a home shop or site built scenario.  No way!   In the long run, buying the SIPS (pre-cut) is both cost effective and easy to do.  Installation is a breeze too.  If you are going to use SIPS, then buy them, don't make them.

[BrianSimmons]

You may have found this, it is a current price list of SIP and curtainwall panels
http://www.sipsproducts.com/price/

This site will give you the basic fastening and foundation support diagrams
http://www.foamlaminates.com/drawlst.htm

I did come across a link a while back that described building your own curtain walls but for the life of me I can't find it. There is something out there. As I recall, it was not a superinsulated panel in that the edges had 2x4 for nailing the interior and exterior panels together. The 2x4 is also used as a tounge on one side. This site stated that it was built for one man installation and the finished panel weighed something like 240 pounds for 4'x12' sections.

Good Luck