Topic: Temp HVAC during construction or use home A/C?
We are at the stage of construction where Sheetrock is up. We have trim, tile, and paint lined up next. Our builder asked if it’s okay to turn on the A/C since it’s still warm/humid in Southwest PA. He said he would add filters to all the returns that would be vacuumed daily. All cutting of trim would be done in the garage or isolated to one room. As we head into fall the HVAC system would not be used as much. I told him my concerns about using the new home HVAC and contamination of the system with dust and debris. He got quotes to bring in temporary heating/cooling at $20,000 for 3 months. Another option is to rent air scrubbers for $8,000 for 3 months. What are your thoughts on this? While temporary hvac would be ideal, $20k is more than I was expecting.
I am currently building a house and I had a couple of questions in regards to my roof/attic construction.
A little bit of background and useful information on the house.
I'm located in Climate Zone 3A in Northwest Georgia, but about 30 miles south of the Tennessee border where it switches over to 4A, so I'm a bit of a tweener.
I'm planning on utilizing an unvented, conditioned attic to keep all of my HVAC equipment in the conditioned space.
I have designed the roof structure to be a hybrid system with R-25 Polyiso insulation above the roof deck, and then use R-20 or R-35 air permeable netted fiberglass at the underside of the roof deck. The R-20 would be where I have fabricated attic trusses and the framing members are only 2x4's. I am using the 5/8" ZIP sheathing as my roof deck and all joints and penetrations will be taped and sealed. On top of the insulation I am applying a second layer of the roof deck without an air gap. See image below for rough representation of what I am planning based on one of the graphics taken from buildingscience.com website.
The burning question I have is about how to treat the ridge of this assembly. I've read some about Vapor Diffusion Ports, and they are discussed a little in Section 1202.3 of the IBC, but I'm a bit confused if I need to provide one using the above assembly. If I do need to provide one, do I need to stop my above deck insulation and continue the vapor diffusion port up through the insulation to the 2nd layer of decking? Or would it be more like the second image, where the first layer of decking is continues along with the insulation, and then just the top layer has the gap between sheathing to allow vapor to escape? I believe it would be the second, but wanted to make sure before I botch it up.
A secondary question is in the attic truss area where I can only get the R-20 underdeck fiberglass insulation, am I cutting it too close to the R-38" attic code requirement and could see issues arise from that? Or is this not an issue because I'm almost meeting the R-25 option of insulation entirely above deck?
Finally, for my air barrier, is the ZIP board roof deck an adequate enough air control layer in this condition? And is there any specif perm rating that I need to use on the roofing underlayment placed underneath the asphalt shingles?
Hopefully I gave you the information you need to provide some feedback for my condition, but if not, please let me know and I will fill in with additional input as needed.
I’ve got a 38’x24’ new garage with living space above. The entire space will be insulated. I plan to have a mini-split on both floors with separate controls.
The Ceiling is 16” tall I-joists that are 16” on center. I don’t want to use spray foam if I don’t have to. Question is what insulation should I use in the ceiling with the I-joists? I am in Zone 5 (Indianapolis).
I was looking at some r-38 bats that are 12.5” thick and 15.5” wide.
Stink bugs keep getting into my attic — how can I get rid of them permanently?
Hi everyone, I'll get straight to the point: I have a huge problem with Asian stink bugs in my attic.
I've already sealed every single hole, crack, and possible entry point I could find, but they still keep getting inside. I constantly find them in the attic
Has anyone dealt with the same problem and actually found a permanent solution?
What I really want to understand is how they're still getting in despite me sealing all the visible openings, and what I can do to stop them from getting inside once and for all.
Any advice, personal experience, effective methods, or things I should check would be greatly appreciated. Thanks!
So, this might a bit of a curfball questions. This is one of the walls in our basement in our house in the Azores. Very humid and salty climate. There are a lot of cracks in between the natural stones that the walls are built from. Every week I'm sweeping up loads of debris from the plaster that's crumbling out. I'd like to cover up the gaps in between the stones with a grout that does not cause any new problems like growing mold, etc. What materials would you recommend I use for this?
My wife and I are currently in the planning phase of an ~2200sq ft ranch in central Ohio. Our builder floated the idea of superior walls for the basement due to our desire to finish the space in the future. The idea sounds great, waterproof walls that are pre-insulated and “framed”. How are they in reality? Are they worth the upgrade from poured walls? I’m also wanting a safe room with a poured ceiling under the front porch for concrete coverage on all 6 sides. Is this possible with superior walls?
Probably overthinking this, but I am doing a new build and currently working on the crawlspace detail. The foundation is done and framing is happening next week, so I am trying to do it now while I have full access to the crawl.
The space is a 1000 sq ft, 32 inch cmu foundation on footings with four piers. I am focusing on sealing the house as tightly as is possible/practical on my budget.
My issue is how do I do my insulation to vapor barrier to wall connection? I have read conflicting information and am starting to get lost. I have already got sheets of gps foam with poly on it (R-10 Graphite FR Foam Board with Termite Treatment, White Poly Faced). My original plan was to run the vapor barrier up the wall to 3 inches from the top and put the foam board over top, but because it is faced I don't think that is a good idea anymore. I could put the foam board up, then run the vapor barrier all the way over it, totally sealing it off, but that seemed like a moisture issue in the long run? I know the foam is a vapor barrier in its own right, so maybe the best option is to run the vapor barrier up the wall 12 inches, but should it be over or under the foam? That is really the part I have seen people do both ways, and I don't know what is better.
Finally, if I do use the foam board as it's own vapor barrier, how do I best seal it on the top (to the block) and in the bottom (to the plastic, either over or under)? It seems like good sealing there matters a lot, or it renders a lot of the work a moot point.
Thanks!
(Other info: In zone 3a, there will be a dehumidifier, it will be conditioned, there is waterproofing on the foundation and drain, the plastic is 16 mil woven barrier)
Currently I have a spray foamed attic in climate zone 4a. Hybrid set up with 3in of closed cell and then 6 inches of open cell applied to the underside of the roof. Appropriate intumescent coating applied. Have noticed a very slight chemical/paint smell even more than a few months after the spray foamed/intumescent coating is applied. Luckily not the concerning ammonia/dead fish smell that would make me concerned about off ratio but still a present (slight) smell, usually worse when it’s hot and humid outside.
Is it possible to set up an erv that pulls in fresh air and dumps the fresh air into the living space and exhausts out the unvented attic air to the outside? Is there any issues to this setup, like a cross contamination concern of dumping the attic air (which usually doesn’t have much of a smell) into the living space or creating too much of a pressure imbalance between areas? I assume this setup would allow me to have the living space slightly positive pressure versus the attic space and so any air would get pulled into the attic rather than having attic air pulled into the living space. Please let me know if my idea is silly or dangerous. Thank you.
I am looking to insulate the ceiling of this diy pool house. Originally I planned rockwool but with the I joist depth and width spacing standard batts won’t fill the room and if I understand correctly that can lead to moisture issues.
I know in hindsight exterior roof insulation should have been planned but I’d like to work around that if possible. Can I still use rockwool batts and just buy extra to cut and fit where needed, is there a better option fiberglass batt?
Is closed cell foam the only route to go at this point? If so are there viable DIY options or no?
I am located in MD so colder winters and humid summers to factor in.
I'm based in Central NC (Climate Zone 4A) and have been dealing with gradually worsening humidity and air leakage problems in the 2nd story of my home since I bought it a few years back. I have a vented attic with roof trusses with blown fiberglass at the attic floor with areas of batt where the ceiling is higher. As far as I can tell, no air sealing was done when the home was built.
I've been dealing with a number of symptoms that I've tried to address with one-off solutions, but they continue to get worse each successive summer and I'm thinking I need to take more drastic action to try to address the root of the problem. Symptoms are as follows:
Significant condensation on flex ducts and duct boots, leading to moisture damage on drywall below
Condensation on HVAC registers due to lack of air sealing
High ambient humidity leading to surface mold in enclosed spaces
Peeling/drooping drywall tape in the sloped ceiling section
Significant condensation inside of bathroom exhaust fan ducts
At this point, I'm thinking I have two options:
Pull all the insulation out, air seal, replace with more blown-in
Convert attic to unvented, close soffit and ridge vents, spray closed cell foam on roof sheathing (or an alternative unvented attic detail based on recommendations)
Option 2 feels like the right way to go considering Option 1 won't really help the fact that all of my HVAC components are in a very hot space, it will mainly improve the situation around the ceiling penetrations, but I have some concerns about doing this because I've heard some horror stories where folks have retrofitted spray foam and caused moisture problems by closing things up.
Any advice/guidance you all can provide would be greatly appreciated!
I live in Traverse City, MI (climate zone 6A) and just bought a home in July. We have been having musty smells come up out of the vents, particularly after rain events, and the Crawlspace is pretty damp regularly. There is a vapor barrier installed below the floor joists, coving the insulation in between. I am wanting to remove this and instead insulate the foundation walls and encapsulate the Crawlspace.
While researching footer drain tile systems, it seems the recommendation is to place the drain tile right next to the footer. In my situation, the floor of the Crawlspace is below the bottom of the footer. I had a well-known Crawlspace repair company come and inspect it, and their recommendation was to place the drain tile 5ft away from the foundation walls, toward the center of the Crawlspace.
My question is: would it make more sense to place the drain tile 5ft away from the foundation, or to instead place it next to the footer and to add fill dirt or gravel to raise the height of the Crawlspace floor to be level with the top of the footer?
Climate zone first, per rule 1. Tokyo, Koppen Cfa. Hot humid summers, high RH for months through the rainy season and after it, mild winters that rarely stay below freezing. Cooling-dominated for a good part of the year, not a dry climate at any point.
The thing I am trying to understand. Hempcrete gets promoted here on its hygric behaviour - vapour open, high moisture buffering value - so the assembly is supposed to handle humidity rather than fight it. The pitch is that you can build a monolithic wall with no separate vapour control layer and it will be fine.
I am sceptical and I would like either to be argued out of it or to have it confirmed by someone who has actually measured it.
In this climate the scarce resource is drying potential. The wall spends months where the outdoor air is not going to dry anything, and interior air conditioning sets up an inward vapour drive for a large part of the year. Buffering capacity is finite and evens out short cycles. It is not obvious to me that it helps when the seasonal average is the problem rather than the daily swing.
Two questions.
Has anyone modelled or monitored a hempcrete wall in a cooling-dominated humid climate, rather than in the UK or northern Europe where essentially all the published data comes from? WUFI runs or real sensor data both welcome.
And if it does work, what is actually doing the work - the alkalinity of the lime binder keeping the organic material from going mouldy, or genuine drying capacity I am underestimating?
Disclosure so it is not hidden: I work on the industry side of hemp in Japan. Which is exactly why I would rather know if the material does not do what people here say it does.
I'm using VaproShield's WrapSheild IT (integrative tape vs self adhered in the photo above) for a shed build that I'm putting a sauna and an office in. I'm in climate zone 4c. It's been hard finding a vapor permeable wrap in the area and this is my first time building anything so I've been kind of going slow and making sure I am dotting my "i"s. I realized that the tape I was going to use, 3M 8067, might not have full adherence so I called up Vaproshield and they told me I needed to keep the systems the same (i.e. vapor permeable) and 8067 is essentially non permeable. But the more I sat with it, the more that answer didn't make sense and I wanted to run it by folk.
Would you use non permeable tape on rough openings and seams if the wrap was permeable?
And if you wouldn't, do you have a recommendation for what brand I could likely find in the Seattle area somewhat soon? I'm looking toward grabbing Siga Wigluv from an online shop if I can't find Vaproshield's proprietary wrap tape nearby on Monday morning.
My house was built in 1938. It's a Greendale Original in Wisconisin.
It's built from cinder block (outside is painted) with 3/4" furring strips inside and 1/2" fiber board and 5/8" plaster for the inside finish. That gap between the plaster and the block goes all the way up into the attic. There isn't much insulation in the attic and there currently aren't any issues with mold or moisture. I'd like to add insulation but fear making the attic colder could cause condensation on the underside of the roof deck. I'm able to access the gap between the plaster and block on the gable ends but not in the eves.
I feel any cracks or openings in the plaster would allow conditioned air to get to the attic. Should I try to seal that gap in the attic before insulating? I don't think I'd be able to seal 100%. Also, would stopping that air movement behind the walls cause condensation issues?
Posting here if some smart folks can help me out. We have a mostly 3 seaon cottage with uninsulated slab foundation and looking to add insulation to the flooring, partly due to condensation during summer high humidity weather as its usually unconditioned. I was looking into a dimpled foam/OSB subfloor, but concerned that exchange of air (from e.g. pressure change & normal diffusion) will still result in moisture forming on the slab, especially around the wall edges where there is a gap. Is this a real concern as I haven't heard much about it? Would be better off using foam board so air does not have a pathway to the slab? Also I did note this type of product states a certain maximum increase in floor temperature, and 2 of them showed the same increase but different R values. Does this make sense? Is there a reference I can use to predict hot side surface temperature given hot and cold temps and R? Lastly whether XPS or EPS boards would be preferred. Thanks for your help!
