There is a possibility that a client will opt for a spray foam insulation package to include living area exterior walls, attic gable walls and attic rafter cavities / decking. This home has typical attic space.
I have never had a client accept the cost of spray foam, being 3-4 times the cost of a typical insulation package in this area of TX.
I spoke to our HVAC engineer / contractor. He is familiar with a spray foam home. We are using three HVAC systems in the large home. He has revised his system sizes, and provided for air exchange.
I am not familiar or aware of any other changes to the responsibilities of sub-contractors or construction techniques, but then this will be a first. There is too much at risk to make assumptions and learn the correct procedures and / or ramifications later.
As I have read and understand to date:
1. Spray foam creates a complete envelope, being sprayed in the walls, to include attic gable walls, and the roof deck / rafter cavities.
2. Even though there are typical “attics” that are not scheduled for HVAC ducting / acclimatization, no separation by additional insulation or air barrier between the attics and the living area below is necessary.
I plan to seek an online info as may be available, and the practical advice from professional design and build forums.
Maybe someone here with professional and successful experience with spray foam can help with additional advice.
Replies
Make sure your flashing is good.
I would head over to
http://www.greenbuildingadvisor.com and post your question in the Q&A section there. Include complete details: climate zone, framing details, type of sheating, WRB, and siding, type of roofing and underlayment, types of foam you are considering, etc.
Thanks David. The site came up in another forum.....will do.
After seeing and studying multiple sources of information about spray foam, and the realization that debates over issues are not conclusive, test this conclusion:
Being my first project where spray foam will be used, as a design-builder I wanted as much info as possible related to performance, construction techniques apart from the spray foam and certain actions which address liability issues.
If I have not provide the information to date, my client's father in law has a spray foam business in New Mexico. He has offered to provide spray foam application for the sum of what our company would pay for our our standard Energy Star insulation package, and travel expenses from New Mexico to this area of TX southwest of Houston.
Since the father in law has created a business directed by a particular manufacturer, uses the manufacturer's equipment and product - the plans, specs, climate zone, framing details, type of sheating, siding, type of roofing, underlayment, and any other information they may request should be submitted to the manufacturer for best practice, and construction technique design custom to the particular home.
My client should ask for written and effective warranty statements from the manufacturer.
Some documentation of the submission, consequent design info from the manufacturer and actual site procedures in following the manufacturer's instructions according to a design for the particular home should be created as we proceed. This scenario should effectively place the responsibility / liability of performance on the manufacturer. In additon, I have told my client that since there seems to be so much unresolved debate over seemingly important issues related to spray foam, he would need to provide a waiver and release of liability in being the final judge as to using the application of the given manufacturer.
To provide an example, James Haride has a nail pattern / location for their lap siding, to vary from the pattern (in some attempt to use varying advice from "professionals" if there were such advice) is to void their warranty.
Pardon me, I don't wish to sound insulting nor do I mean any disrespect.... but, you sound like a guy who is trying to get everyone and anyone but yourself to take the responsibility in case this job goes south. Perhaps you should excuse yourself from it.
Sap,
I submit questions as I am open for discussion:
Some BT members call me TX, is it OK to call you Sap?
Is your advice based on big picture knowledge of business practices and experience?
What does the fact that Houston based and large builder service provider Williams Insulation mean to you in understanding that they provided an expensive and long evaluation period prior to their offer of spray foam service?
Do you understand that the absence of a warranty expressed or implied in TX, to include terms, conditions, limitations etc. does not legally release a service initiator (builder) or provider from liability in serving expectations?
If you were faced with the introduction of a product and service for which found multiple sources of debate amongst professionals related to construction techniques, building science and performance, potential problems such as nesting of insects, “outgassing”, moisture, etc. would you openly accept liability and responsibility, to include issues such as the health of clients? Should I ignore the debates, or pick a side and roll on?
Have you ever seen pictures of the long term damage caused by EFIS, and aware that a complete redesign of construction techniques related to installation details was necessary and implemented? If you were not directly named or responsible for unknown performance of the product and installation, would you want your client to be subject to future problems?
Have you ever seen photos of mushroom and other organics growing from the inside of composition siding? Again, if you were not directly named or responsible for unknown performance of the product and installation, would you want your client to be subject to future problems?
Are you familiar with Chinese drywall problems? Again, if you were not directly named or responsible for unknown performance of the product and installation, would you want your client to be subject to future problems?
Why was CCA treated lumber re-examined and the use limited after years of installation in common and ordinary residential projects?
Are you indicating that my cautionary path is in self preservation and interest, and has nothing to do with my client? (Note here that this question and answer should be used in an evaluation of your advice that I should excuse myself from the project.)
Are you indicating that my cautionary business path is in self preservation and interest, and has nothing to do with my family and their future?
If you are / were a design builder in areas of questionable soils, would you require a soil test, submission of the soil test to a structural engineer and rely on his evaluation and of the soils load bearing capacity, shrink swell potential, structural load calculations, assumption of liability and responsibility, consequent design and your compliance as builder in that his name is listed with PE after?
Am I making a mountain out of a mole hill in my detailed and exhaustive discovery work related to an important building science with far reaching effects?
Why has it been said and written for centuries that if a man chooses to engage a matter (perhaps design and build a home) he is considered a fool if he does not take liabilities / cost into account (and effectively deal with the issues)?
Being that you have suggested I provide self examination, do you have the maturity and experience to answer these questions in a manner acceptable to those qualified to evaluate business advice, providing a test of your advice related to business knowledge and practices in your own openness to self examination and qualifications?
Wisdom is proved out by her children.
No doubt I completely misinterpreted the meaning and intent of your prior questions and concerns. Please ignore my silly ideas as I shall do with yours.
I was serious. To suggest my ideas are silly is to argue with a construction career that started as a frame carpenter in 1971, a current design build firm that has a list of clients waiting for our service in design build projects.
Like a native Indian chief who wears many feathers in his head dress due to considerable accomplishments, we have confidence in our leadership promoted, substantiated, recognized and defended by those who know us.
Like Churchill said when the US joined World War II, “The only thing lacking is the proper application of overwhelming force.” Like a boxer who has learned boxing, trained properly and thoroughly, and has an exemplary record of success, we are confident and enter the arena with champion music and considerable accompaniment.
If you ever make it to the Houston area and let me know, I will take you to lunch.
“Life is tough; it is even tougher if you are stupid.” John Wayne
“The difference between genius and stupidity is that genius has its limits” Albert Einstein
(BreakTime) “A great place for information, camaraderie and a sucker punch.” Calvin BT Member
Who you be talking to….for reals? A former pot smoking renegade Tennessee born frame carpenter, who has mellowed, is generally easy going and laid back, and found out all things are possible. See attached pic and link. I grew a goatee for a Daughters of the Confederacy banquet event primarily involving my wife, and kept it through a winter vacation in Roatan, Honduras. The beads were woven in at the encouragement of my wife and children.
http://brotherscustomworks.com/photo-gallery/showcase-project/
I've used some foam on both new houses and additions.
My opinions are based on my experiences inMichigan
I prefer the closed cell version with the last few jobs done by a Corbond franchise holder. I have also used an independent contractor that installed a closed cell product, but became dissatisfied with his workmanship.
I have also tried the DIY two component products on smaller jobs with mixed results.
I have also used an open cell product (Icylene). This was also used in two jobs and their attics. The first was a new home where it was sprayed to the back side of the ceiling drywall to a depth of about 8". Another addition had the backside of the roof sheathing sprayed, making the attic a conditioned space.
For my two cents worth (and you may be overpaying), I would use a closed cell on the walls but not in the rafter bays.
I am just not comfortable with that over the long haul of roof maintenance. For my climate the attic area is best done with blown in cellulose.
I realize that your job requires use of the attic for mechanicals and can only suggest some combination of spray foam and blown-in to seal up the attic floor.
Terry
I would call Icynene and pick their tech staff's brains until you get satisfying answers. I've read much of their site & observed their staff posting commentary on multiple web message boards. They truly seem to have the science part figured out - but local code interpretations are the wild card. Some AHJ's require flame retardant paint or some such coating if the attic will be used for storage. I believe in it, but I also understand your interest in hearing from others experiences before jumping in to something new.
The wet lumber encapsulation concern is a real eye opener!
If you want a conditioned attic space without the spray foam, you might consider rigid foam/sandwich panel for the roof sheathing. The wall to roof "envelope" continuity is a little more tricky to detail (but not that hard since there are no soffit vents).
also check here: http://www.buildingscience.com/doctypes/designs-that-work/dtw-case-studies/bsc_climatemap_view?climates=hot-humid#climatemap_anchor