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Posted: Feb 28, 2011 01:23 PM	moisture Mason I am a sprayfoam contractor out of Michigan. We installed a conditioned attic assembly in August of 2010 which was 2" closed cell and R-19 unfaced fiberglass batt. The home owner did not finish or condition the room all winter. He just recently went to install the drywall and discovered the fiberglass was wet. I am completely baffled at what would cause this. The only resonable explination in my mind is that the condensation formed due to the fact that the room was not conditioned. Could you shed any light on this?
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 28, 2011 02:58 PM	Troubleshooting... Welcome to the world of flash and batt! This is the problem that we've been seeing in the market since the inception of flash-n-batt and yet it still continues. As a matter of fact,surprisingly, some code officials even endorse it. We've had many of the same calls, but luckily and thankfully, we didn't do the insulation. That's why we won't do flash-n-batt type of installs. Because it still allows mositure to pass through the fiberglass coolling it as it passes through and when it reaches the foam on the inside, it condenses! Yes, even with 2" of closed cell foam. So, no matter how much foam you put in, it can still condense on the inside of the foam as the air cools as it passes through the filterglass. So, the correction I would see, is to tear out the filterglass and spray some more foam in to prevent condensation. This can be open of closed cell. Jim
Posted: Feb 28, 2011 03:08 PM	Thanks for the input, but this doesn't answer my question. I am perplexed on why the condensation formed if the space remained unconditioned. I don't believe the condensation would have occured if the space was conditioned. The only answer I can come up with is that the relative humidity in this bonus room was high, leading to condensation forming on the foam and the fiberglass obsorbing it. I have seen uninsulated pole barns condensate and I have to imagine this is the same issue. I have performed 100 or more of these applications without a single issue. I know that solving pulling out the fiberglass and spraying more foam would solve the problem. But I need to know why this happened.
angus mcdougald Posted: Feb 28, 2011 04:35 PM	Take a building science class (We teach bpi classes here in NJ ;) ) First, to me you have described a conditioned attic. you have unvented the roof, and the heat is from the house. You should add more foam (usually the best answer) and that should fix it, but things like showers sweat steam rooms ext also you might as well sell a combo cc oc jobs instead of filter trash.... it can be a similar price to fiber..... Also r19 I believe is 6 inches... plus the 2 in foam is 8. Are the rafters 2x8s? Also if he added the drywall sooner it might not have happened .... I think you need a better description to really problem solve other then more foam
steven argus Posted: Feb 28, 2011 06:14 PM	Unvented roofs are only permitted with air impermeable insulation. Installing fiberglass in an unvented roof is a code violation, even with the 2 inches of foam.
Posted: Feb 28, 2011 07:02 PM	A little more information. I just visited the job site and only one half of the roof is condensating, that being the side that the sun does not hit. The rafters are 2x8 so 2" closed cell foam and r-19 fit perfectly. In regards to the code, I have met the code with the application of the closed cell spray foam and the batt is for additional insulation at a more cost effective price. If it was a code violation, it would have failed inspection. I rather just spray foam, unfortunately, cost dictates the scope of work and the hybrid option was chosen by the homeowner. Back on topic, any ideas why half the roof is condensating?
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: Mar 01, 2011 06:20 AM	Yes, It's condensing on the North side of the roof because it's colder than the south side. You're right on the edge of being ok! As the air passes through the filterglass, it cools off and will ultimately condense when it reaches a surface. This surface has to be colder, but not much colder. The root cause is the filterglass! It allows air flow through it and will allow condensation to occurbehind it or in it. The root cause is not the foam! The foam is doing just the job you asked it to! Jim
Posted: Mar 01, 2011 06:41 AM	so just to review what is know: 1.) I have installed 2" closed cell foam and R-19 fiberglass batt conditioned attic assembly 2.) Homeowner has not finished or conditioned the space 3.) Condensation is forming on the North side of the roof and only the North side (starting about 1 ft down from the ridge and extending to the bottom). Jim, you are suggesting that the air is cooling as it passes through the fiberglass, touches the cold side of the roof and condeses. That seems like it is just the opposite of what it should be. In other words, the warmer south side of the roof should be condensing if the air was cooling. And how is adding more foam going to eliminate this? It seems to make more sense that the air is warming (because of windows and associated radiation) and touching the cooler side and condensing. I don't disagree that the fiberglass is holding the moisture. It seems that by eliminating the cooling down and warming up of the air, by conditioning the space, would solve my problem...anyone agree?
steven argus Posted: Mar 01, 2011 07:52 AM	Your code official is misinformed.
mason Posted: Mar 01, 2011 11:18 AM	If I read the posts correctly, there is no heating or air conditioning in the house at the present time. If so, then yes I can see condensation forming on the surface of the foam under the right conditions. Even if the attic is sealed, there is still outside air coming in the house and drifting into the attic. In the daytime, this air tends to be more humid and warmer than at night. I would have to do some dew point calcuations but it seems to me that it is possible to have enough warmer humid air in the attic space that could condense overnight. This happens frequently on sprayfoam roofing applications. When you spray the roof deck with foam, it attracts the dew and a lot of water forms on the surface overnight. This may be happening in the attic if the attic temperature is allowed to vary. Remember the adage, "Seal tight, ventilate right" also must include "Condition the space so the temperatures are right" Let me know if I don't have the right situation.
angus mcdougald Posted: Mar 01, 2011 02:46 PM	I think he is describing a house that is being lived in. 2x8s are 7 1/4 House could be too tight, doubt it though Hour long showers and a leaky ceiling? Fiberglass does not stop air motion convective currents ect Fiber glass needs no air movement to work Fiber glass sucks Oc instead of glass- what would it have cost you? Maybe 500 -1000? The air hits 2 inches of foam and condenses most likely. it gets cold where you are right? If you put up batt insulation on a ceiling, but no drywall, the insulation will have zero r value. Similar world.....
steven argus Posted: Mar 01, 2011 06:28 PM	Mr. inspector must have done a drive by inspection. Whish I had some of those guys in my town.
Posted: Mar 01, 2011 08:41 PM	Mason The room insulated was a bonus room that sits over a conditioned space. The room was not conditoned all winter. Here in Michigan, we obviously are a cold weather climate so the temperature of this room was significantly cooler than the rest of the home. The rest of the home is heated with propane, which I am told gives off more moisture than natural gas. The room was sealed shut via an insulated door. So based on what I know, my hypothesis is that the air of the bonus room dropped at night, warmed up during the day, rose to the spray foamed roof deck which was cooled from the night before where it then condensed on the first condensating surface...the foam. If this space had been conditioned, I have to believe this situation would not occur as the surface of the foam would be within a couple of degrees of the ambient temperature as the rest of the room. Pretty sure this is the problem. I needed a day to rap my brain around this one. It just confused my when only half the roof was condensing (not to mention I think my brain locked up from the sheer panic of the situation truth be told). As for the rest of my fellow contractors posting, I get it. You don't like hybrid systems involving fiberglass. However, I have used it with much success. This is the first time I have encountered a problem. I am not a big fan of fiberglass, but if used correctly in conjunction with cc foam is a cost effective alternative. Even if I had never installed the fiberglass, the same exact thing would have happened. Even if I sprayed 2 or 3 more inches of cc foam...the same thing would have happend. Simply because the room was not conditioned...and probably not ventilated. Guiness, I would love to be able to spray 7" of cc foam to achieve an R-49. Unfortunately, it isn't realistic for the following: 1) It is not cost effective 2) Diminishing returns of cc foam after 3". 3) I would never spray foam because not many people could afford to have rooflines sprayed to those thickness. Most of my work is retrofit and additions. (A legacy report from BASF or any of the manufactures showing that 3 to 4" of cc is more than enough would be nice) Thanks for the feed back fellas.
SprayFoamSupply.com Posted: Mar 01, 2011 09:56 PM	I have enough posts on these boards about my feelings on flash and crap and I wasn't going to chime in, but... Troubleshooting states, "This is the first time I have encountered a problem". You can't say that as how many of these jobs are still without drywall? You don't know what is happening in the walls. I personally have had 4 or 5 calls this season with similar condensation issues from contractors or homeowners. On guy cut some 4" holes in his drywall with a hole saw and there was condensation in there. I think he only had 1.5" cc and then a batt. George
Posted: Mar 02, 2011 12:17 AM	I would say well over half my spray jobs are in dormer style attics where the dywall is not dirctely against the insulation and I never used anything less than 2" of cc. I have visited several of these jobs and never encountered a problem. Granted, this doesn't mean condensation hasn't occured on any of the jobs, including those with drywall installed. But the same can be said for any straight sprayfoam job. We rarely go back and look, so in reality...we don't know. The major benefit of using only sprayfoam is that it will allow the condensation to evaporate quicker. Condensation is caused by a set of environmental circumstances...and it certainly isn't caused by the fiberglass. My only objective is to find the reason for the condensation, which can only make me a better insulator. I really rather just spray foam. After 7 years of spraying...it is just the cleanest and easiest way for me. But if I was one dimensional, I would not have survived as a business owner.
angus mcdougald Posted: Mar 02, 2011 07:04 AM	What would oc cost instead of filter? Propane is natural gas... No real difference. You are confusing an issue of when you use work space heaters that aren't vented outside. If the combustion air is into the house your custie has more problems then that. First let me say that there can be many problems or a combo of problems at any building. Part of "troubleshooting" is being A detective. We have energy auditors who do this... You should make friends with one or take some classes or read some books. There's something about a dew point that dude or mason know more about. At a certain depth of foam the dew point temp is we within the foam. At that depth in foam, no water vapor or vapor filled air is there to condense. Computer programs exist to model this..... If the drywall were installed and air sealed pretty well, it might not have happened. You may have a venting problem ..... Blower door test pressure test. Audit Air moves right around and through filter glass.... Heat rises. Hot air goes around and through the fiber in your system
mason Posted: Mar 02, 2011 07:32 AM	Troubleshooting, I would agree with your analysis of the situation. Heating that space should reduce the potential for condensation. Just remember the basic principles of heat, air and moisture transfer within the building envelope and take all the variables into consideration. If you have a condensation issue, then it is caused by too much humidity in a space for the surface temperature Check out the temperature and humidity levels in the home. For example, a house that has 55% humidity and is kept at 72 degrees F would have condensation on any surfaces that drops to 55 degrees. Some things to consider: 1. Fiberglass over foam will cause the foam's surface to be slightly cooler in the winter due to the insulative effects of the fiberglass. This may require another 1/2 of closed cell foam in a hybrid system than would be necessary with just the closed cell foam by itself 2. Make sure mechanical vents are working, are used, and do not vent into the attic. 3. When spraying foam, it will make the building tighter, thereby increasing the humidity level in the home. You may need to add make up air to reduce the humidity level in winter. Heat recovery ventilators can be used to help remove water vapor and condition air going into the house. But I agree that once that space is heated up, it would be less likely to have a condensing surface.
steven argus Posted: Mar 02, 2011 08:07 AM	TB, I'm sorry to be a richard here, but how is 2" of CC and a R19 filterglass an R49? I barely grauated, but the math don't add up. Why don't you try spraying the roof decks w/ OC? Spray on a vapor retarding paint. If the inspector accepted your unvented flash and crap, he won't make you paint the foam w/ Ign. Paint. Did your R19 have the kraft facing on it? If so, you have 2 vapor retarders, the CC and the paper. This is not the way to insulate in your climate. You will trap the moisture in the roof assembly. Heat is very sneaky. It will slip past the kraft facing and the filterjunk, bringing the water vapor with it. Hits a dew point surface and bingo, condensation and it can't get out. Mold, rot and angry customer, not a good combo. In my redneck way of thinking, if you call yourself a "spray foam contractor", you spray foam. That's it. You should refer to your self as an "fiberglass contractor" who sprays foam every now and then. No offence intended, sorry, just my opinion.
Posted: Mar 02, 2011 09:37 AM	Mason thanks for the input. I will be surre to check the humidity level. Brightalt Switching back and forth between cc and open cell is a pain in the ass. Not to mention you get stretch of bad foam after you switch over, foam that can't decide if it is open cell or closed cell. Guiness 1.) Your right..R-14 plus R-19 = R-33 which is better than R-19 alone. The only thing this home owner could afford was this option or maybe a 3" foam only option. He chose the higher R-value. 2.) Unfaced fiberglass batt was used (see original post) 3.) I'm a spray foam contractor who turned into a full service insulation contractor...and I can tell your a redneck...no offense intended.
John Shockney Posted: Mar 02, 2011 12:06 PM	Troubleshooting I am guessing that this a bonus room over the garage, this can pose a moisture problem as the cars bring both heat and moisture in that can travel though the wood and sheetrock ceiling/floor between and there is normally not a vapor barrier installed because ?what side is the warm side that it should be installed? So if that is the case, then that is where the moisture is coming from, then the solar heating and cooling cycles are just moving the moisture to the coldest part of the space where it will condense back into water. It is a fact of physics that where a liquefied gas (water) and that gas (water vapor) are in the same container (the room) the gas will travel to the coldest point and convert as much gas to liquid (water) as the heat being removed will allow. With the info that you have given I think that it will be ok if the space was finished and heated after any wet insulation was removed/replaced and dried out.Moisture will always travel from warm to cold keeping the mosture from the garage out of the bonus room. Now just some thoughts about your sales of the flash and batt system, for the same cost as the 2inches (R-14) of closed cell foam you could have sprayed 7inches+ (R-27) of open cell and not used any fiberglass. When you take into account that the R-19 fiberglass will only perform at R-10 in the cold weather you get in MI that lowers your flash and batt system down to an R-24 so are you giving your customer the best bang for his buck are not? Just some thoughts. Airpro
steven argus Posted: Mar 02, 2011 05:48 PM	TB, no offence taken. I am a redneck. I do have a truck garden out in the back field, there was a point when Tyvek was used for siding on my house, we all own tractors out here and I wave to every one who drives through my town. Anyways, swithching between foams is a pain. We do it on most of the jobs we spray. We drain 2 1/2 gallons out of the lines. We also installed a "T" on each of the whip lines so we don't have to break down the gun every time. We fill up a garbage bag half way with foam. We have a system and it works.
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: Mar 03, 2011 07:46 AM	What I'm suggesting is that warmer air holds more moisture than colder air. As the air warms up from the south side of the house, it wil hold more moisture. Warmer - moister air is also more bouyant so it will rise. So, when it comes in contatc with the north side of the house, it will condense on the colder surface which is the foam. That is after it passes through the filterglass and cools itself down to the dewpoint. So, with this scenario, you get condensation on the underside of the foam. So, this is a bonus room over a gragae? So, what was used to insulated the floor of the bonus room? Fiberglass? Cellulose? This can be where your excess moisture is coming from. Now, with this area being heated, you can actually prevent this from condensing because warmer air holds more moisture! Is there a set back thermostat in place/ being used?So, the warmer the air the more moisture it can hold and the less likely it will be to condense. It's when we get in this 60-70F scenario that we typically have the problems. Especially with a setback thermostat. So when the thermostat sets back to 62F then it will allow the mositure to condense out on the coldest surface. When the furnace is up and running steady at 70F-72F steady it should prevent the condensation - depending on the coldest surfaces of the room and the RH. So, the first question is where is the moisture coming from? The garage? Answering this should be able to help. Thanks, Jim
mason Posted: Mar 03, 2011 08:57 AM	Jim makes an important point. Consider the garage as outdoor space. Then it is easier to know how to insulate it correctly. If you have a bonus room over the garage, you would insulate the floor of the bonus room. Sprayfoam will not only provide good insulation and reduce water vapor driven into the house, but will also stop unwanted odors from stuff stored in the garage and carbon monoxide from your cars into the house
Posted: Mar 03, 2011 03:32 PM	The bonus room is over a conditioned room, a bedroom and a utility room. There was at least an R-30 cellulose installed on the floor of the bonus room. I believe that your hypothesis is correct Jim. As the room was not conditioned at all, the air was cool from the night before. As the day wore on, the air warmed (either by rising from the room below, convection from the windows or both), rose and condensed on the North face of the roof as that side was still cooler. The answer is simply to condition the space, therefore stabilizing the room temperature. Problem is that the homeowner is now saying he never intended to condition the space. I told him if he kept the room to an even 50 or 60 degrees this problem will not happen and with the room being insulated so well, it will not increase his heating expense in any significant way. Bottom line is he needs to condition the space regardless of what his original intenions were. Guiness thanks for being a good sport. I was a little miffed when you called me a fiberglass guy who sprays foam occasionally...I am really not. Just a sprayfoam guy fighting to survive. Jimcoler and Mason thanks for taking the time to help me figure this out...I really do appreciate it and hope I can return the favor. and finally I will consider using open cell in the future. I have been reluctant to use it as I have read some articles about the dangers of using it in cold weather climates. BTW...what do you guys think about vapor barriers on oc foam. I think they are necessary in cold weather climates. Boomberg actually wrote me a letter about conditioned attic assemblies and stated he is not in favor of oc foam in cold weather climates.
steven argus Posted: Mar 03, 2011 04:31 PM	TB, sorry you were miffed. I guess I just like pushing buttons. And, I can't stand fiberjunk. We get out bid all the time by guys throwin filterglass or newspaper on top of foam. Most of the problems with OC you see on the internet is ICY brand. They promote 6" in the roof deck w/ no VB. Big problem up north. We pump in 10" and either vent, spray the roof deck no vent w/ VB paint, (we call it a coating and charge more. LOL) or the IB paint which is also a VB. We also recommend HRV's, quality bath fans and kitchen fans, all vented to outside. OC is a fine choice as long as you treat the building as a system. And don't forget, stoping moisture laden air movement through the wall assembly is a major component to eliminating moisture problems. Remember, Fiberjunk is the enemy. And all of us on this forum are foam geeks. No offence.
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: Mar 03, 2011 10:20 PM	No Problem abot us trying to help you out! That's what we're here for. I use OC in roofs in upstate NY all the time. We typically wil use 6-7" f OC on the underside of the roof without any issues. So, what is the leter that Mr. Bomberg sent you? Can you send me a copy of it? Thanks, Jim
Posted: Mar 04, 2011 09:09 AM	Jim ya...give me your e-mail and I will send you the pdf.
Posted: Mar 04, 2011 09:22 AM	me too perty pleez foamdudeatmidwestpolydotcom
John Shockney Posted: Mar 04, 2011 10:01 AM	could you send me a copy too or three I guess airpro@gotsky.com Thanks John Airpro
Posted: Mar 04, 2011 01:41 PM	foamdude...tried to e-mail you the letter but your e-mail is not recognized. Give me a good e-mail and I will ship it off to you.
Brad Smith Posted: Mar 04, 2011 02:05 PM	If you would be so kind please send a copy to brad@sprayfoamsolutions.ca Thank You.
Posted: Mar 04, 2011 02:31 PM	arrg,,time to 1 bullet barney the provider.. try foam-it@mchsi.com
Posted: Mar 04, 2011 03:40 PM	Your copies have been e-mailed. I think that after reading that letter, you can see why I have been hesitant to use oc foam. That and an article I read about an Icynene project that ended up being full of moisture and mold. I still have that article if any of you want it. Couple those two references with the fact that mold has been written out of home owners policys and it was enough to scare me away from oc foam. I checked into getting mold coverage for my GL. I would need polution control (the same coverage for asbestos abatment contractors) and that policy runs a cool $20,000....ummmmm...no thanks. Believe me, I would love to spray it as it is easier...much easier IMO and much more profitable.
Circle-D Posted: Mar 04, 2011 08:28 PM	I'd take a copy of that documentation also, thanks for the thread.
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: Mar 05, 2011 11:54 AM	jim"at"coler"dot"com
Posted: Mar 08, 2011 05:12 PM	I jumped in a little late. But am I too late to ask for a copy of that letter?:-) defordinsulating@gmail.com Thanks
ChrisIgna Posted: Mar 08, 2011 09:48 PM	i would also ask for a copy of the letter candr.insulation@gmail.com thanks Chris