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Posted: Feb 08, 2011 12:50 PM	FINALLY SETTLED - REALLY!! to have the sprayfoam applied. Thanks to this forum and tons of research on the internet, I have concluded I will have my attic done as follows. Attic will stay vented 3" CC foam applied to attic floor (exiting batting removed) After much going back and forth, it seems to make a bit more sense to do the attic floor to me for these various reasons. 1. attic is low pitch and will never be a living space 2. sprayfoam the attic floor will keep the envelope around the true living space 3. no worry about intumescent paint or drywall over foam since the attic floor drywall is the fire break. 4. can always add batting if wanted down the road to satisfy the twshp in case of a CO issue when I sell the home. 5. leak or damage to roof line easily viewable There are some other less important reasons but all in all I am happy with how this will go. Thanks to everyone!
philip mullins Posted: Feb 08, 2011 01:30 PM	food for thought... cc foam adds stregnth and water resistance. oc foam is cheaper. do you need strength and water resistance over the ceiling? either foam can cause issues with certain lights if not installed correctly when spraying this type of system. and care must be taken when spraying cc foam down on sheetrock. what we call "potatoe chipping" may occur. and the easy fix for that, when possible, is a huge pain in the...
philip mullins Posted: Feb 08, 2011 01:41 PM	in case ur not familiar, potato chipping is what we call it when ur ceiling warps and buckles. looks kinda like a big potato chip
Posted: Feb 08, 2011 03:02 PM	I guess the potato chip effect is caused by the weight of the closed cell foam or the delivery agent wetting the sheetrock too much? What causes it with closed cell and what should be done to prevent it?
philip mullins Posted: Feb 09, 2011 01:23 AM	caused by the heat of the reaction in cc foam. and the strength of the pull of the foam. cc when sprayed on sheetrock needs to be sprayed in thin passes first to insulate the rock from the heat of the foam. the thicker you spray it the hotter it gets. most manufacturers say no more than 2 inch passes when spraying to wood cause the excessive heat comprimises the foam and could even set wood on fire. people have died this way! houses have burned! if the foamer u hire knows what he is doing u shouldnt have any issues. but cc down on the ceiling isnt exactly common in this industry. we usually seal the attic or put open on the ceiling
Posted: Feb 09, 2011 03:38 AM	Seems to me you are saying wood can catch on fire if done wrong? If that is the case why would the ceiling be worse then the roof line which is all wood. At least sheet rock has a burn rating and is resistant to heat (to a point) at least much more so then wood at the roof line. I can somewhat understand your point(s)and I have made sure out of the two contractors I am looking at, one is certified by demilec and the other is a manufacturer of spray foam. I do hope all goes well since it would be par for the course with this home of mine if it does not. LOL
jimcoler I have over 10 years of experience specifying and installing open and closed cell spray foam. I've sold my business but I'm still selling for the new owners and consulting on large and custom specific jobs. I've expanded my knowledge into t Posted: Feb 10, 2011 08:56 AM	I would suggest with a low pitch roof, spraying the underside of the roof with 6" of open cell. But if you insists on spraying the back side of the drywall, then I would say seal off all of your can lights and fans with a fire barrier type of product and then spray them in. Just hope you don't have to get back up there and change any of them or do any modifications with the wiring because it wil be sealed in. The you might need to have someone come back out and shoot it again for you after you pul the foam out to make the changes. That's partly why I recommend spraying the underside of the roofdeck. Also, 6" of OC foam will provide enough R-value to meet the code if you compare it to the typical performance of Filterglass (1/3 stated R-value). It can also be done in one pass or two directly behind each other. The potato chipping as it was called is probably due to the moisture content inside the house being absorbed into the drywall and being emitted by the propane space heaters/flame throwers inside. As the foam heats up, it will expand and then contract and the damp sheetrock can bend some allowing it to buckle in the middle between the rafters. We had this happen on one job an the Architect/Owner INSISTED on spraying closed cell to the back side of the drywall in his own home. It did cause potato chipping and they had to re-apply drywall on the inside of the the drywall. Not a pretty situation when we got into it. Just my 2cents! Jim
John Shockney Posted: Feb 10, 2011 11:06 AM	I agree with Jim. Low pitched roof how are they going to get a good 3inches of closed cell out to the walls at the rafter tails without getting foam outside through the soffit vents. And not get voids or thin foam where you cant see it. I would stuff fiberglass into the soffit and fill all the corners with open cell and spray 8 inches (R-31) of open cell on the underside of the roof that should still cost less and give you more insulation than 3inches of closed cell (R-21at best.) just look at spray foam yields 15,000 verses 4,500 board feet of foam and the chems cost about the same and take the same labor to spray. I can spray that 6-8 inches in one pass on the underside of the roof. Airpro
Posted: Feb 10, 2011 02:16 PM	The one contractor will use rafter baffles to make sure the soffits do not get blocked. I do not see why this would not work no matter the pitch. I have also told these two contractors that if needed, they can remove my gutters and soffit vents to get clear access to the roof line to MAKE sure nothing is blocked. I only have 1 device that needs to be covered and it is the bathroom fan. All other electrical connections are for ceiling fans and light fixtures and from what I gather, can be sealed and sprayed over with no harm to wiring or junction box. Just to restate the reason for all of this is to stop ice damming which is causing leaks in my home. I would like to know who if I do the roof line, seal the attic and the attic stays warm (conditioned) the ice dam will still not occur? I know there will be a minimum of R21 on the roof line but heat will eventually pass through it to the cold roof and warm it up? Does this go away with higher R values or does the cost prohibit this? Also if there is a roof leak, where and how do I find it without ripping out alot of foam? Now this is verses doing the attic floor which seals in the living space, super insulates the flue (major cause of ice dam) and allows for the attic to remain cold do to it still being fully vented? I also figure that if there is still an issue after the attic floor is done in this fashion, I could always add gable vents to pull in cool air from the soffits and exhaust warm up. Lot's of great info on the forum but I am still leaning towards the attic floor unless an argument comes up that explains the good, the bad and the ugly of each system (cause I know there is) and it is easily shown which one is a better solution
Posted: Feb 11, 2011 05:54 PM	After interviewing actual applicators, (not sales people) a spray foam company owner no where near me and consulting with ann architect who is certified with spray foam application. I am going the roofline route for a closed vent system. Thanks to all who helped me as this forum has many people who sincerely want to help and were able to get me past the confused state I was was getting myself into. Thanks
Posted: Feb 12, 2011 06:04 AM	Here is what is going to happen 1. remove and discard all fiberglass batting insulation (my choice) 2. seal gable vents with polystyrene board 3. Install high temperature AES wrap and mechanically attach it to the furnace flue to completely cover it and seal roofline and attic floor penetrations with fireproof caulk. 4. bathroom vents flexible pipe insulated with fiberglass wrap 5. Minimum 3" Closed Cell on roof line as well as seal ridge vent with min 3" closed cell. 6. Apply Open Cell to seal soffit/eave areas of whole attic) 7. Minimum 2" Closed Cell on Gable walls and over polystyrene boards covering gable vents. 8. Apply Open Cell JUST to attic floor over mechanical room 9. paint gable walls with intumescent paint 10. Crawlspace rim joist area and down cinder block wall 4" with 2" closed cell
Posted: Feb 15, 2011 05:51 AM	Now the hard part, picking a contractor. The main problem I have is most of the contractor's quotes are ignoring my requests. I can understand it may differ from their thoughts on how to do things but to just ignore it 100% and not talk to me about it is terrible. Best thing that happens with them is they get ignored by me. The process of determining what may be the best solution for my needs was very hard but choosing the right contractor is 10 fold that. I have prices from $4000 to $12,500 which is such a spread and it is hard to know the cause. I am thinking materials are pretty much a standard price across brands (BASF, Demilec, Lapolla etc.) give or take a few hundred. So is the giant differential caused by labor price or something I am missing? While I have settled on what the project is, I have not settled on a contractor and I will be having two more come for estimates. Maybe I am just a pain for these contractors because I ask too many questions and have my own ideas? If that is the case and I was a contractor, I would take that as a challenge and work with the customer to reach an understanding about the product, installation and expertise in applying it. Back to the quote grind as I call it!
SPFer Posted: Feb 15, 2011 06:36 AM	What is the reason for painting just the gable walls with the intumescent paint, and how is it a good idea to cover only a portion of the exposed foam with it?
Posted: Feb 15, 2011 06:38 AM	NJ code which follows international code requires the gable walls to be fireproofed (either intumescent coating or sheetrock) if the space will be considered a living space. Because I will be using the attic for storage, it is considered living space. I can only think because the gable walls essentially hold he roof up, if the burn is slowed you have less of a chance of a roof collapse before the fire department comes. Now I have been told by numerous contractors this is code but damn if I can find it on NJ International Code.
SprayFoamSupply.com Posted: Feb 15, 2011 08:25 AM	Where to begin? Sorry for chiming in so late, but I was at the sf conf last week. You mention that one of your main reasons for going with foam is because of ice damming. I do not believe that 3" of cc foam or 6" of oc foam to the underside of the roof will completely stop ice damming. What is the framing of your roof? 2x6? 2x8? You are going to have thermal bridging occur that will lead to some snow melt and some damming. It should be very minimal in your climate. Spraying the attic floor will do a better job at controlling ice damming as it will eliminate alot of the thermal bridging, except where the roof meets the exterior wall. Do you just have a small access hole to get into your attic? Your prices are all over the place because you have a difficult job from an application standpoint. A 4 pitch roof? Think about that, when the contractor is 3 feet away from the downhill edge of the roof, he has 1' of space to spray in. 6' away and he has 2' height to work in. It will be very difficult to spray 3" of cc foam no matter if it is to the roof or the floor. For foam to be installed correctly without voids, you need a skilled applicator. Potatoe chipping? I have never heard it called that, but think about this; As anything that is hot cools, it wants to shrink. If you spray 3" thick pass of cc foam it can get up to 200 degrees internally. As that foam cools to ambient temp, there is a negative pressure that is created inside the closed cells. The adheasive properties of the foam are greater than the negative pressure and with wood framing there are usually no issue. When spraying the back of drywall, the drywall is not as strong as plywood and as the foam cools, it shrinks marginally and pulls the drywall up between the framing. That is why you need to spray cc on drywall 1/2" - 1" for the first pass or two. If you are going to use the attic for storage, you need to paint the whole attic, not just the gable ends. Not sure if you read the article about vented attics by Roger Morrison, but it is good reading and is easy to understand. Link at left Good Luck, George
John Shockney Posted: Feb 15, 2011 11:30 AM	Hi Mark. It seems that your contractors have forgotten the “Golden Rule” “The one with the gold makes the rules” or the translation: “The customer is always right” It is the job of the contractor to make recommendations and advise the customer but the bottom line is to do the job the way the homeowner wants it done as long as it is safe, meets code, and will do the job that the customer wants to accomplish or solve the problem that he has. If the contractor thinks that the customer’s specs won’t do the job then he should advise the homeowner (giving the reasons) and make recommendations to correct the problem. Airpro
Posted: Feb 15, 2011 11:35 AM	I read the article and seemed like the attic floor was the way to go until a mitigating factor came into play. I have returns in my attic as well as want to use it for storage. Because of this, the article recommends roof line.
Posted: Feb 15, 2011 11:37 AM	That is what I am looking for. While I "THINK" I know alot about this service, I do understand I may be wrong or right. However, without a contractor showing me their viewpoints etc, I have to refuse to consider them. If they yest me to death, same thing because then it tells me they just want to make money period and are not that concerned about their work. It is hard work finding a contractor you can trust and one that seemingly is an expert in their field. Hence,I have another contractor coming Friday!! I am in need of this service but will be damned if I settle for a contractor that is not customer service oriented and very experienced in the application. Airpro, I appreciate all your input as it helped more then you know!
maurice richter Posted: Feb 16, 2011 07:54 PM	That is so disturbing that contractors are ignoring your specs. Sounds like whoever you choose you should make sure there is a contract stating type, thickness, etc, and how it is to measured? Is it worth asking some to re-bid or to clarify why? As for the highest prices, would some have priced it so high to discourage you from picking them? (I'm starting to look into spray foam too...)
Posted: Feb 16, 2011 10:03 PM	Not sure if they were trying to discourage me from using them but rather then trying to get more money out of me. I have again changed what i will be doing basically because the main reason I went this route was to stop the ice daming. Sprayfoam the attic line is a good idea but not the most economical and possibly not the most sensible choice right now. I am still researching and will post more.
Posted: Feb 19, 2011 08:54 AM	Here is what I have done (just hired all contractors so no backing out now LOL) 1.Attic Roof line: 3" Closed Cell Lapolla 2.Garage ceiling/attic floor over garage is being sealed off with a 2" foam wall leaving that area vented and separate from the newly conditioned space. 3.crawl space sill plate/rim joist with " foam 4. power direct vent furnace with horizontal vent pipes and power vent HW heater with horizontal vent pipe 5. abandoning type B flue pipe in attic which means NO MORE HEAT build up to melt ice or need to insulate it with high heat blankets. I feel I got a group of contractors that were able to answer questions assist me with understanding the technology and all agree this is the route to take to prevent future worries. Thanks everyone!!!!!