Structural Insulated Panels or Std 2x6 construction?

[rlme36]

Hi all,

I have plans for a 30x36 approved, using 2x6 walls, clear span 14' ceiling and storage above. I just recently started to look at SIP's and was wondering if anyone is using/used this for the contruction of their garage? It seems compelling from a insulation standpoint. I was planning to insulate with a spray in form and then use fiberglass on top. Any thoughts?

located in CT if that is any help and going back through an approval process does not sound very appealing, but if they are *** much better I would consider it.

thanks

rob

 

[rsanter]

I think it will come down to cost difference.
the spray in foam and the SIP should give close to the same R value and both will eliminate the the R value of drafts.
SIP has a benifit of going up quick and reducing labor cost but there are several other factors to look at
what is your local labor cost VS the upcharge on the SIP pannel
who is doing the construction? you? contractor?
local codes.

bob

 

[rcleaver]

The people who make panels want you to believe you save labor in installing them. But your paying for MORE EXPENSIVE labor to make the panels in the first place. I got several bids for all kinds of panels and the results were OUTRAGEOUS. All of the bids were more than TWICE as much as I estimated to do it myself (i.e no labor charge). The SIPS bids were the highest, for insulation that you just don't need (do some research if you don't believe that).

Bottom line -- I'm making some jigs for easy wall framing, and renting the equipment I need to do it myself, with a few day laborers here and there. I expect to save about $90k just on framing for a house and three car garage. Now I'm actually thinking about doing the slabs myself.

If you do it yourself, it may take longer but you then have no one preventing you from getting the job done right. I'm fed up with the labor available around where I live now.
Edits are in bold.

 

[Steve in Mi]

I expect to save about $90k just on framing.<!-- / message --><!-- sig -->

Probably more than a two car.

I didn't catch the edit rcleaver.

 

[bluesman2a]

When I started my build, I was VERY interested in SIP, ICF (insulated concrete form), and other alternative construction methods. There are OBVIOUS advantages over traditional framing. The problem as previously mentioned is cost. All were prohibitively expensive and I couldn't find anybody locally who was qualified.

On mine I ended up just going 2X6 traditional stick frame, in retrospect, I would either go that again or a pole-barn.

 

[BooUrns!]

All of the bids were more than TWICE as much as I estimated to do it myself (i.e no labor charge).

Bottom line -- I'm making some jigs for easy wall framing, and renting the equipment I need to do it myself, with a few day laborers here and there. I expect to save about $90k just on framing for a house and three car garage.

If you do it yourself, it may take longer but you then have no one preventing you from getting the job done right. I'm fed up with the labor available around where I live now.

Speaking from experience, I do know how DIY labour can save you money. I don't see how you are going to really save yourself money if you don't already work in the trades and own your own set of tools and equipment and possess the knowledge of how to use them effectively. BTW: two times zero is still zero.

If you were going to be paying $90k for framing, I really need to come to your area and take on a few jobs. I've never seen a residential framing job that exceeded $50k and those bids were for multi-million dollar homes.

Correct me if I'm wrong but it sounds like you don't agree that there is a fair price for skilled labour. Perhaps prices are high in your area or there is a lack of skilled trades, but seeing the condition of the US housing market, I would assume that labour prices have become very reasonable.

A warning on using SIPS: Athough they are a great idea for saving on-site labour costs, there are hidden costs. Typically, you will need structurally engineered and stamped drawings when building with SIPS. It is difficult to find structural engineers willing to take on residential projects and they are very expensive (huge liability insurance costs for them). They are superior to conventional 2x6 platform framing but unless the design costs are included by the manufacturer, they are not worth the price. Note that most ICF manufacturers include stamped drawings with their products.

 

[thdewey]

I looked at this myself. I would love to build a SIP house. The extra cost would be recouped by the superior insulation and lack of any air leaks. You will never get your money back even in the long term on a garage. If you are building both a house and garage, maybe there some cost savings from the builder but I wouldn't know. The only way to even breakeven on increase in equity is to build it yourself. Protect your equity has been my moto for my build. I hired a contractor to put up the Hardie board siding and trim. Again this was to protect the value.

 

[rcleaver]

Speaking from experience, I do know how DIY labour can save you money. I don't see how you are going to really save yourself money if you don't already work in the trades and own your own set of tools and equipment and possess the knowledge of how to use them effectively. BTW: two times zero is still zero.

If you were going to be paying $90k for framing, I really need to come to your area and take on a few jobs. I've never seen a residential framing job that exceeded $50k and those bids were for multi-million dollar homes.

Correct me if I'm wrong but it sounds like you don't agree that there is a fair price for skilled labour. Perhaps prices are high in your area or there is a lack of skilled trades, but seeing the condition of the US housing market, I would assume that labour prices have become very reasonable.

A warning on using SIPS: Athough they are a great idea for saving on-site labour costs, there are hidden costs. Typically, you will need structurally engineered and stamped drawings when building with SIPS. It is difficult to find structural engineers willing to take on residential projects and they are very expensive (huge liability insurance costs for them). They are superior to conventional 2x6 platform framing but unless the design costs are included by the manufacturer, they are not worth the price. Note that most ICF manufacturers include stamped drawings with their products.

I'm a very experienced DIYer. The first house I built for myself was in 1978. I've been doing woodworking since about 1960. I even have a CNC machine and almost all the tools and equipment to build a house.

I didn't say it would cost $90k for the framing -- I said I would SAVE $90k by doing it myself. (I'm including windows, doors, and roof and wall sheathing in the framing). I plan on using the same approach as panelizers, using jigs and screws or auto nailers. The garage will be first, so I can do the rest under cover.

I didn't say there wasn't a fair price for labor. I said my recent experience is that the labor I have used was incompetent. Besides, who will do it better than me.

Edit: SIPS manufacturers around here will review and seal the drawings.

BTW, I actually went to the panelizers' and SIPS plants to observe what they do and how they work. I picked up some good tips and techniques that I will use for my DIY project. Fortunately for me I can devote full time to the work.

 

[rcleaver]

I looked at this myself. I would love to build a SIP house. The extra cost would be recouped by the superior insulation and lack of any air leaks. You will never get your money back even in the long term on a garage. If you are building both a house and garage, maybe there some cost savings from the builder but I wouldn't know. The only way to even breakeven on increase in equity is to build it yourself. Protect your equity has been my moto for my build. I hired a contractor to put up the Hardie board siding and trim. Again this was to protect the value.

I don't understand. There is NO insulation advantage to the SIPs -- it just extra insulation that's ineffective. There are a number of threads here that make the same point.

Building the house and garage myself provides a ton of sweat equity, especially since I know what I'm doing. I just finished the basement in my current house by doing all the framing, drywall, electrical, plumbing, flooring and custom cabinets. Here's a partial picture of it:

 

[Stuart in MN]

My next door neighbor built a SIP garage a couple years ago, and he loves it. The garage has three stalls on the first floor, along with a full second floor that serves as his wife's studio for her fabric business. I don't know the exact numbers, but I recall the material costs were higher than stick built but he figured with the ease and speed of construction it was pretty much a wash. He and a couple friends set all the first floor walls by hand, and he hired a crane for a day to set the second floor walls and the roof (they assembled the panels into large sections on the ground and flew them in with the crane.) It's very easy to heat and cool, and it's very quiet. If I were to do it over, I'd build my garage the same way.

 

[rcleaver]

In case you haven't noticed, almost all building products have increased in price since hurricane Katrina in New Orleans. In my area the prices have DOUBLED. They may start to come down soon, and I'm waiting to see before I start building anything.

In case you're interested, the SIPs bid on my house was $166k!

 

[Stuart in MN]

Besides my neighbor, I know another guy here in the Minneapolis area who built a timberframe house using SIPs (another DIY project) and his costs were very competitive as well. It's been a several year project for him; he was working on it this summer, and didn't mention there had been any big jumps in the price of the materials. From what I've read on the subject the price of SIPs varies quite a bit, depending on what part of the country you're in. Go to the Fine Homebuilding or Journal of Light Construction forums and poke around for a while, there are plenty of discussions on the subject.

 

[thdewey]

I don't understand. There is NO insulation advantage to the SIPs -- it just extra insulation that's ineffective. There are a number of threads here that make the same point.

Building the house and garage myself provides a ton of sweat equity, especially since I know what I'm doing. I just finished the basement in my current house by doing all the framing, drywall, electrical, plumbing, flooring and custom cabinets. Here's a partial picture of it:
QUOTE]

I agree completely about the sweat equity! But I think that the nay sayers of SIPs only look at the R valve from a square inch perspective. When studs, other non-insulation objects, air leaks, penetrations and insulation installation defects are taken into account, a SIP wall with the same R value as a stick built in the real world would have a much greater overall energy savings. For a garage with a big, at best poorly insulated door, where's the benefit? Again, unless you are using the garage for a business i.e. you are occupying the space everyday for hours and are conditioning the space, why spend the extra money?

 

[dps]

I think you need to consider the total short and long term costs. SIP construction is usually price competitive with stick built. It beats stick built in erection time which will save you money if you're on a construction loan waiting for an occupancy permit for permanent financing. If the timing is no issue it doesn't matter.

SIP's have superior insulation and air infiltration qualities. Infiltration is pretty much moot if you're opening huge doors often. Same for insulation; if you're working or lounging in it often, it will be more comfortable and cheaper to heat or cool. If it's mostly a storage building, then there's no advantage.

There is probably an added resale value to a SIP garage if the buyer plans to spend time in there for the same comfort and energy cost reasons as you might be considering. Again, this may mean nothing to you if you're pretty sure the place won't ever be sold until after you're past caring.

 

[rcleaver]

I think you need to consider the total short and long term costs. SIP construction is usually price competitive with stick built. It beats stick built in erection time which will save you money if you're on a construction loan waiting for an occupancy permit for permanent financing. If the timing is no issue it doesn't matter.

SIP's have superior insulation and air infiltration qualities. Infiltration is pretty much moot if you're opening huge doors often. Same for insulation; if you're working or lounging in it often, it will be more comfortable and cheaper to heat or cool. If it's mostly a storage building, then there's no advantage.

There is probably an added resale value to a SIP garage if the buyer plans to spend time in there for the same comfort and energy cost reasons as you might be considering. Again, this may mean nothing to you if you're pretty sure the place won't ever be sold until after you're past caring.

I see I have not made myself clear. Maybe at one time SIPs was price competitive with stick built, but not now, at least in my area. I have BIDS, not estimates, for panelizing, SIPs and stick built. Here are all the bids; judge for yourself.

Stick built $98k
Panelize $160
Panelize $203k (this included more stuff than others)
SIPs $166k

 

[rlme36]

I think it will come down to cost difference.
the spray in foam and the SIP should give close to the same R value and both will eliminate the the R value of drafts.
SIP has a benifit of going up quick and reducing labor cost but there are several other factors to look at
what is your local labor cost VS the upcharge on the SIP pannel
who is doing the construction? you? contractor?
local codes.

bob

That is what I was assuming regarding the spray in foam as well. There have been may points made above that given the use, its probably not worth it. the stick built estimate weather tight, no insulation or interior work done is about $45k with shingles and exterior siding for my 30 x 36. Concrete is coming from a diff contractor.

 

[dps]

I see I have not made myself clear. Maybe at one time SIPs was price competitive with stick built, but not now, at least in my area. I have BIDS, not estimates, for panelizing, SIPs and stick built. Here are all the bids; judge for yourself.

Stick built $98k
Panelize $160
Panelize $203k (this included more stuff than others)
SIPs $166k

You made yourself clear. Others have stated that costs are typically in line with other forms of construction. That is generally the current case in my part of the country as well. Perhaps your bid or your locale is more of an anomaly as you had already stated.

 

[brad d]

What does that spray foam cost? the kind that fills the whole cavity up..

 

[larry4406]

Rcleaver - go stick built, put tyvek on the outside, air seal all of the studs/connections on the inside with foam/caulk - this is what the company i worked for does in all of their production homes in NOVA ($750k-$1.3M). At that point, make a decision to either put in spray foam or batts. Southland in manassas does spray in foam (isonene sp?) but was too much for my $. I went 2x6 walls with the above and R19 batts and R30 ceilings.

I agree with you on the quality of labor - this area is flooded with individuals who are incompetent and should be called wood butchers vs carpenters. Fortunately, caulk and paint makes a carpenter what he ain't.

 

[rcleaver]

You made yourself clear. Others have stated that costs are typically in line with other forms of construction. That is generally the current case in my part of the country as well. Perhaps your bid or your locale is more of an anomaly as you had already stated.

I didn't say it's an anomaly and I don't believe it is. The bidders were all from different states on the east coast.

Do you have some vested interest in SIPs? Or maybe your just not interested in changing the conclusion you reached for some time in the past.

I have no vested interest in any approach. I'm looking for the best value. Based on these outrageous bids, I will use the DIY approach to avoid the labor costs. I can save about 50% vs. the stick-built bid.

BTW, the bids were for a large house and a large 3 car 2 story garage connected to the house by an enclosed breezeway.

 

[rcleaver]

Rcleaver - go stick built, put tyvek on the outside, air seal all of the studs/connections on the inside with foam/caulk - this is what the company i worked for does in all of their production homes in NOVA ($750k-$1.3M). At that point, make a decision to either put in spray foam or batts. Southland in manassas does spray in foam (isonene sp?) but was too much for my $. I went 2x6 walls with the above and R19 batts and R30 ceilings.

I agree with you on the quality of labor - this area is flooded with individuals who are incompetent and should be called wood butchers vs carpenters. Fortunately, caulk and paint makes a carpenter what he ain't.

The pro insulators are saying more than 2" of foam is a waste of money (edit - which means that SIPs are a waste of money). The foam just seals against air infiltration.

I was thinking of another approach, using Advanteh for the walls and roof (you seal it using tape) and then something like a rubber strip on the wall studs and roof trusses to seal them when the sheathing is applied, so I wouldn't need any foam. I don't know of anyone that's tried this approach and I need to research it more, but I think the concept is sound.

 

[rlme36]

Rcleaver - go stick built, put tyvek on the outside, air seal all of the studs/connections on the inside with foam/caulk - this is what the company i worked for does in all of their production homes in NOVA ($750k-$1.3M). At that point, make a decision to either put in spray foam or batts. Southland in manassas does spray in foam (isonene sp?) but was too much for my $. I went 2x6 walls with the above and R19 batts and R30 ceilings.

Since I'll be finishing the interior at my own pace (read slow) this sounds like a great solution. Just sealing the gaps with the foam/caulk should help considerable for air infiltration. That is a lot of those little foam can's though

 

[larry4406]

Our insulation contractor was responsible for the air seal package. They used normal painter's caulk, the type that is available in bulk for about a $1/tube at the home depot/lowes. They just sealed all of the framing connections (plate to floor, doubled up studs, double top plates, sealed back of the electrical boxes where the romex came in, etc). I did this to may basement before I enclosed it, and was surprised at the amount of drafts it stopped.

 

[dps]

I didn't say it's an anomaly and I don't believe it is. The bidders were all from different states on the east coast.

Do you have some vested interest in SIPs? Or maybe your just not interested in changing the conclusion you reached for some time in the past.

I have no vested interest in any approach. I'm looking for the best value. Based on these outrageous bids, I will use the DIY approach to avoid the labor costs. I can save about 50% vs. the stick-built bid.

BTW, the bids were for a large house and a large 3 car 2 story garage connected to the house by an enclosed breezeway.

No, I have no interest in any form of construction, I thought I was merely trying to present a balanced approach when considering any and all methods for building anything. Initial cost is of course important to most people, but only each individual can decide how much weight to give that; there are many other long term costs and non-economic benefits or disadvantages involved in any method that might be chosen.

Here, and in much of the West, SIP's are initial cost competitive. Other posters pointed out the same. Especially for someone concerned about the (lack of) quality of labor available for stick built, SIP's are quality controlled and require far less field labor.

And of course one can build it themselves and save on labor, but some people can earn more than they pay out, so economics would dictate that they not do it themselves. Of course economics doesn't take into account a sense of control or accomplishment or enjoyment an individual might gain by doing it himself, so, once again, initial expense might not mean everything when weighing a method of construction. And neither of these two statements takes quality into consideration. Do-it-yourself COULD mean the finest workmanship or a piece of **** in the finished product.

So all I was trying to do is to raise questions that any thoughtful person might want to consider before making a decision.

 

[dps]

The pro insulators are saying more than 2" of foam is a waste of money (edit - which means that SIPs are a waste of money). The foam just seals against air infiltration.

Either a) the pro insulators are talking about more that 2" of foam is a waste in terms of infiltration stopping abilities only, which sounds about right, and that the rest could be made up of less expensive fiberglass,

or b) you need to talk to some pro's who are actually knowledgeable. The more insulation, the better as far as ultimate comfort and utilities economy are concerned. This assumes insulation properly placed and sealed, which is a big assumption! As an experiment, a house (or maybe it was several) was built in Sweden that was so well insulated that it could be heated with a 100 watt light bulb. In practice (it was lived in) it meant they had to vent excess heat generated just from the occupants and the appliances.

Now that much insulation takes a heck of a long time to pay off in terms of money saved tomorrow versus money spent today. That's why there are suggested R-values published for different parts of the country; those values reflect the best compromise between initial cash outlay compared to future energy savings. Of course if the price of energy changes, that will skew those numbers such that more insulation will be required.

The reason that spray foam insulation has become so popular despite its higher placement costs is because it is so much more effective at both stopping infiltration and because of its higher effective insulating values compared with the standard slipshod installation of fiberglass. The spray foam still can't compete with SIP's or other panellized construction in overall, or true R-value because of the bridging effect of the framing lumber.

Once again, let me say I'm not trying to push SIP's on anybody; only trying to keep any comparisons fair.

 

[Weedwaka]

Look into advanced ( or stagered framing ) methods using standard stick. That in combination with spray foam will get you great results and with lumber so very cheap right now. The basic idea is to prevent studs from bridging the wall front to back. You use more studs but but there so damn cheap who cares. This way they do not creat a thermal bridge which is where most your heat loss is on a standard fully insulated stick frame wall. Either 2x6 plate with stagered 2x4 studs or 2x8 plate with stagered 2x6 I beleive.

We also looked into SIPs but could not get them around here. We are doing our main floor of our 42 x 32 in ICF ( insulated concrete forms ) . This was the best solution for us as we are dug into the ground quite a ways ( on a hill ) and some of the added cost of blocks and concrete / rebar is saved by labour. The top floor ( room in roof ) is going to be insulated with spray foam and use stagered framing on the peak exterior walls.

If your climate is mild I would just frame it up standard and insulate.

When it gets really cold up here ( -25 C or below ) I notice how drafty and uncomfortable standard 2x6 framed houses are. Cold spots etc. I bet 90% of that could be fixed with the use of spray foam insul.

Let us know what you end up with and why =)

 

[rcleaver]

Either a) the pro insulators are talking about more that 2" of foam is a waste in terms of infiltration stopping abilities only, which sounds about right, and that the rest could be made up of less expensive fiberglass,

or b) you need to talk to some pro's who are actually knowledgeable. The more insulation, the better as far as ultimate comfort and utilities economy are concerned. This assumes insulation properly placed and sealed, which is a big assumption! As an experiment, a house (or maybe it was several) was built in Sweden that was so well insulated that it could be heated with a 100 watt light bulb. In practice (it was lived in) it meant they had to vent excess heat generated just from the occupants and the appliances.

Now that much insulation takes a heck of a long time to pay off in terms of money saved tomorrow versus money spent today. That's why there are suggested R-values published for different parts of the country; those values reflect the best compromise between initial cash outlay compared to future energy savings. Of course if the price of energy changes, that will skew those numbers such that more insulation will be required.

The reason that spray foam insulation has become so popular despite its higher placement costs is because it is so much more effective at both stopping infiltration and because of its higher effective insulating values compared with the standard slipshod installation of fiberglass. The spray foam still can't compete with SIP's or other panellized construction in overall, or true R-value because of the bridging effect of the framing lumber.

Once again, let me say I'm not trying to push SIP's on anybody; only trying to keep any comparisons fair.

I have read several posts here by several pro insulators who say more than 2" of foam is a waste of money. I asked a pro insulator local to my property to give me an estimate using foam. He also recommended no more than 2" of foam. I also asked him for an estimate using foam as thick as that used in SIPs. He came back with a $43k estimate.

If you're referring to the passive house in Darmstadt then I believe your conclusions are not correct. That house was a passive solar house and I saw nothing about dumping excess heat. If that's not what you are referring to, then perhaps you can provide a reference.

For a guy not pushing SIPs, you seem to be, well, pushing SIPs. There are a number of other ways to provide a thermal break that are far less expensive.

 

[rcleaver]

Look into advanced ( or stagered framing ) methods using standard stick. That in combination with spray foam will get you great results and with lumber so very cheap right now. The basic idea is to prevent studs from bridging the wall front to back. You use more studs but but there so damn cheap who cares. This way they do not creat a thermal bridge which is where most your heat loss is on a standard fully insulated stick frame wall. Either 2x6 plate with stagered 2x4 studs or 2x8 plate with stagered 2x6 I beleive.

We also looked into SIPs but could not get them around here. We are doing our main floor of our 42 x 32 in ICF ( insulated concrete forms ) . This was the best solution for us as we are dug into the ground quite a ways ( on a hill ) and some of the added cost of blocks and concrete / rebar is saved by labour. The top floor ( room in roof ) is going to be insulated with spray foam and use stagered framing on the peak exterior walls.

If your climate is mild I would just frame it up standard and insulate.

When it gets really cold up here ( -25 C or below ) I notice how drafty and uncomfortable standard 2x6 framed houses are. Cold spots etc. I bet 90% of that could be fixed with the use of spray foam insul.

Let us know what you end up with and why =)

It's funny you should mention that. I just recently did spend some time considering using a second framed exterior wall. There are some posts here about that. IIRC, one guy decided just to insulate both frames using fiberglass, because the air gap alone eliminates the thermal bridge.

I still haven't decided what to do, but I will do some sort of thermal break even if it's just applying a gasket to the studs and plates etc.

 

[Stuart in MN]

I have read several posts here by several pro insulators who say more than 2" of foam is a waste of money.

That may depend on where you live. The R-value of foam insulation is something like 6 or 7, I believe, so 2 inches would only be R14. In my area I think a minimum of R21 for walls is expected in new construction, with R38 or so in ceilings. Many people insulate well beyond those minimums; it comes down to what they can afford up front, as well as the payback when comparing the initial cost of insulation versus potential energy savings over the life of the building.

Another important thing about foam insulation is that it does a good job of sealing off air infiltration. It turns out that fiberglass batts don't work very well at all if the building envelope isn't covered well with an air infiltration barrier like Tyvek or tar paper, with all the edges around windows, doors, etc. sealed.

 

[rcleaver]

That may depend on where you live. The R-value of foam insulation is something like 6 or 7, I believe, so 2 inches would only be R14. In my area I think a minimum of R21 for walls is expected in new construction, with R38 or so in ceilings. Many people insulate well beyond those minimums; it comes down to what they can afford up front, as well as the payback when comparing the initial cost of insulation versus potential energy savings over the life of the building.

Another important thing about foam insulation is that it does a good job of sealing off air infiltration. It turns out that fiberglass batts don't work very well at all if the building envelope isn't covered well with an air infiltration barrier like Tyvek or tar paper, with all the edges around windows, doors, etc. sealed.

I wasn't saying you shouldn't use more than R14. I was saying you shouldn't use more than 2" of foam.

 

[Stuart in MN]

I wasn't saying you shouldn't use more than R14. I was saying you shouldn't use more than 2" of foam.

Okay, I'm not getting it...then how would you increase the R value beyond 14? Put in 2" of foam, and then use fiberglass or something else on top of that? I can see where the raw material cost may be less, but it would involve more labor.

 

[rcleaver]

Okay, I'm not getting it...then how would you increase the R value beyond 14? Put in 2" of foam, and then use fiberglass or something else on top of that? I can see where the raw material cost may be less, but it would involve more labor.

Yes. All of the pro insulators I've contacted, both on this board and locally, say to use no more than 2" of foam to stop the air infiltration. The use the much less expensive fiberglass to achieve the desired R value. For those that want to reduce costs, install the fiberglass yourself. On the other hand, some say a pro can install the fiberglass for less than you would pay for just the insulation. I guess it depends on whether you can buy the insulation at less than retail.

 

[b4z]

New to this board and this is my first post.

There are 2 different types of spray foam. closed cell which has a high r value of 6.5 inch and open cell which is much lower(i think around 3.5). Open cell is also used within interior walls for sound insulation purposes. It is also used to spray under rafters
when encapsulating attics. They are saying my attic won't get over about 90 degrees in the Summer with 2" of foam. Estimate was $4500 for our 1650 sqft house with an 8/12 pitch. All ridge vents, power vents, gable vents and gable are foamed up.
Part of the reason I am invstigating this is because I want to start playing the drums again and would have them in the attic. The neighbors will probalby appreciate the noise reduction.

Closed cell is more expensive than open cell..

I think you also have to factor in comfort. I'm not sure if spraying a lot of foam insulation will ever pay for itself in savings but I bet the eveness of temps inside and comfort are better.

I'm also thinking that with a lot of foam insulation there is a mass advantage, just like with a log cabin where once the mass is heated or cooled it wants to stay that way and is easier to keep at that temp.

Closed cell also provides a structural component which is important if you live in high wind areas or earthquake prone regions.

SIP houses have been torn off their foundations by tornados and remained intact.

 

[rcleaver]

New to this board and this is my first post.

There are 2 different types of spray foam. closed cell which has a high r value of 6.5 inch and open cell which is much lower(i think around 3.5). Open cell is also used within interior walls for sound insulation purposes. It is also used to spray under rafters
when encapsulating attics. They are saying my attic won't get over about 90 degrees in the Summer and they spray 2". Estimate was $4500 for our 1650 sqft house with an 8/12 pitch. All ridge vents, power vents, gable vents and gable are foamed up.
Part of the reason I am invstigating this is because I want to start playing the drums again and would have them in the attic. The neighbors will probalby appreciate the noise reduction.

Closed cell is more expensive than open cell..

I think you also have to factor in comfort. I'm not sure if spraying a lot of foam insulation will ever pay for itself in savings but I bet the eveness of temps inside and comfort are better.

I'm also thinking that with a lot of foam insulation there is a mass advantage, just like with a log cabin where once the mass is heated or cooled it wants to stay that way and is easier to keep at that temp.

Closed cell also provides a structural component which is important if you live in high wind areas or earthquake prone regions.

SIP houses have been torn off their foundations by tornados and remained intact.

Edit: I'm aware of the different types of foam insulation and I suspect many others here are also aware of it. What is open cell foam used for? Is it old technology that's obsolete and still hanging on? I wouldn't consider using it.

I believe you will find there is a better way to provide soundproofing besides insulation. I don't believe insulation is the same as sound deadening. For example, my current house is insulated to the hilt, but I can hear the bass component of the audio in some the the kids cars that drive by the house, about 150 ft away. Some of it comes through the windows, but I think it also penetrates the walls. I haven't spent any time trying to figure out why I don't hear the voice or treble component, but I suspect the house is acting as a low-pass filter.

I've seen some clips you can use for sound isolation. You can also build another wall separated from the outside wall to provide a thermal and sound barrier. Does anyone know of any relevant scientific studies that may help here?

 

[b4z]

I believe styrofoam is open cell.

When we build our garage it will be a 4 car tandem 2+2. 1 back bay may be a room within a room for the drums. Or I may put the drum room in the apt. that will be above the garage.
it will be used for guests not a rental.
But for right now it will go in the attic. they recommend we do the new roof first, then
open cell foam.
It does work for sound attenuation. I imagine that the long waves of the bass drum will still be heard and I know my wife in the room below will hear it throught the fiberglass insulation and plaster. May build a small riser with rubber feet to decouple it from the floor.
Lots of options.
i've pretty much written off the Sips even thought the garage will have HVAC. I think the payoff is too long.

 

[rcleaver]

What does that spray foam cost? the kind that fills the whole cavity up..

I got a bid on it for my project from a pro insulation guy. I checked him out and I believe him to be an honest guy.

He quotd a price for all foam to fill 2x6 walls at R30 and the ceiling at R38 (all this for zip code 18830, northeastern Pa, -15 F design temp). It was $43k. OMG!!!


Edit: I should also add that he didn't recoommend this approach. I asked for him to provide a bid for foam to fill the cavity. He said to use no more than 2" of foam and the rest fiberglass.

 

[NillaRita]

I noticed these posts are from 2008. Would anyone like to chime in please with a current opinion on the cost of Stick vs SIP? We have JUST begun the process - chosen a plan for construction at this point. Now we are looking into construction materials & the only info I seem to be able to find online is generated by the manufacturers of SIPS so that is not valid IMO. We would be using contractors in Colorado for the framing so that IS part of the cost consideration for us. If we were building ourselves then it seems according to the previous posts there would be no advantage to SIPS. I would rather hear from end users of the products. I am also hoping that by this time there have been people that have used & lived with the SIPS.... what has your experience been thus far?

 

[yeldogt]

The newer part of my studio is SIP's -- built in the early 2000's. Walls and the roof. I did not build it ... previous owner.

It is extremely tight and energy efficient ....Mine is OSB on both sides with drywall attached to the interior OSB from the factory. Very quiet.

The roof is long panels cut into a ridge beam -- so I think it went up very fast -- it has to be cheaper than stick and spray foam.

All the electrical is surface on mine -- so no holes in the panels -- this would not work in a house.

Standard way of installing windows and doors -- siding -- roof shingles. No venting... so none of those issues. Just order the jams to fit -- the thicker walls.

The big thing is running electric and plumbing -- some thought must be given ...some of the panels have channels already in them.

The early panels had insect issues if not flashed properly -- like any different building material -- special things must be done.

 

[NillaRita]

You bring up a point I had not considered - later wiring. The SIPS I have been researching have the channels for wiring but what happens in these buildings later if I want to add an outlet, additional lighting etc? Is it even possible without major surgery to do that after construction is complete other than doing the wiring on the surface I mean.

 

[Mooniac]

I've watched a couple of TV shows showcasing SIPs and other engineered homes, and it appears to me that there is no practical way to run future/after-thought electrical/plumbing without major surgery. I think the best plan is to carefully plan what you're going to build in the first place, but I suspect you could have the channels cut large enough (to some upper limit I imagine) to act as a conduit to route future additional wiring. If the channels are located carefully, I could envision cutting a new hole for an outlet or a switch box through the interior facesheet, and then "excavating" the interior to reach the nearest channel. Maybe that could work. It would still be potentially tricky to run the new wires since you'd have to turn a corner(s) in the channels, vs. running vertically in a conventional stud wall with access from above or below.