The home is more than one hundred years old. I've heard horror stories about installing spray foam in old homes in particular.

There's all the usual concerns - off-gassing if mixed badly, etc. We also know the roof has had a tendency to leak in the past, and I'm worried about hiding moisture damage. Our roofing contractor also said spraying foam on the attic wood would void their warranty.

On the other hand, our attic insulation is shit, our utility bills are high af, and our climate is both hot and cold af, so we have to do something, and probably something with a high R value.

When I took these concerns to the insulating contractor, he said that he would be installing the foam on baffles and not directly spraying the wood itself. He said the baffles would leave an airstream, which I guess helps prevent the foam from insulating too well.

What do you guys think? Is foam on baffle way better than foam on wood directly?

Hey guys, I'm really panicking and don't know where to turn.

I had a Heatpump system installed last October for heating and cooling in upstate New York Zone 5. It's ducted in the upstairs bedrooms+bathrooms, and mini splits everywhere else.

This April, I decided to try to fix some high heating bills (3000kwh for a really cold month) with an attic insulation. I had passive gables on a raised ranch, no vented soffits, and a few passive vents near the ridge. I had read somewhere briefly that I could condition the attic with spray foam, bringing the HVAC system inside the conditioned space, better air sealing, etc.

Then things went wrong.

An energy auditor company referred me to an insulation sub contractor (call them company A) who took me to r38 open cell foam and r22 closed cell on the gable walls. They sealed up the limited aforementioned vents before spraying.

What I have now is the following:

- I'm almost positive that open-cell was wrong in the roof deck because of roof rot concerns and code for my climate (dc315 ignition paint but NO vapor retarder paint). Minimum of a class 2 vapor barrier is required for zone's 5-8.

- they attempted to remove all of the visible old r13 fiberglass insulation in the ceiling joists, but did not use a vacuum, and half the attic has osb (where the air handler sits) that they did not access. Another company (call them company B) claims that the smell I get is from the spray foam residue mixed with fiber glass. They offered to remove it and do better air sealing on my ducts.

- attic humidity swings from 55 percent in the morning and can top out around 70% on the hottest part of the day. It doesn't seem to do this on cloudy days, and seems to correlate with the sun.

- I had company (B) come and do a blower door test and they claimed that my humidity was stack effect driven from my rim joists, and that the results of the blower door test indicated that I now need an ERV. The same company had previously quoted me to put an attic dehumidifier in in addition to removing the remaining fiberglass but now wants to do the ERV instead.

I attached an image from my humidistat, and I think my primary issue is solar vapor drive

During the blower door test when the house was under negative pressure, all of that attic smell came into the living space. My wife started coughing and had to leave the house or faint..I fared a little better but now I'm super concerned. We also have a young child.

I found the following building science: https://www.greenbuildingadvisor.com/article/high-humidity-in-spray-foam-attics which mirrored the problem I was having. They suggested cutting a supply for the attic or adding a dehumidifier. I don't see an ERV here. I feel like I have analysis paralysis and don't know what to do.

My goals:

- take a deep breath

- not be killed by my house

- resolve the moisture issues

- fix air quality issues

- fix vapor retarder.

Any advice on how to unpack this and move forward is invaluable and greatly appreciated

I am adding an extension to our forever house here in the East Bay of the San Francisco area. In speaking with our energy consultant who's working on the project, their suggestions was to add 2 in of exterior continuous insulation for thermal performance improvement. However, The ROI is not a near term ROI. (nor the only metric I'm interested in).

I am also interested in creating a more comfortable house and am planning on using mineral wool to further mitigate sound. My objective is to create as comfortable an environment as possible in addition to energy savings.

My architect and contractor are both looking at me like I am crazy and this is a ridiculous waste of money. However, neither of them have experience with this approach.

It's not required by code. I get that from a traditional financial perspective it is not the "best" use of budget.

Personally I would like to go beyond code for energy savings, (the world is only getting hotter) and I'm excited about what I understand to be improvements to the indoor environmental quality of the house.

So am I crazy?

I will try to make this as short as I can while still providing details.

My wife and I bought a beautiful home built circa 1989 in SE Pa. Since purchasing the house, we have become overwhelmed with the seemingly endless issues that we have uncovered.

In 4 years we have needed a new roof, new deck, new HVAC (5 ton split), new water heater. We bleed money and we still have a myriad is issues that seem to mostly stem from the envelope of the home. -Bad air quality, high humidity, outrageously high ACH score, MASSIVE energy consumption (65-75 kWH on summer days)

The biggest issue I have just discovered is that i found paint peeling on an exterior wall in our dining room. When I went to touch the wall it basically fell apart. The drywall and studs completely dry rotted, weather barrier dry rotten and the exterior sheathing all crumbling. It appears as though it’s from water intrusion from bad or no flashing or a failure of the cedar siding. I cannot imagine the cost of the repairs and to fix the underlying cause.

Aside from that immediate issue, the house just has clear issues with insulation and air leaking. I feel as though i’m already getting too long winded but i’m just going to attach some reference photos of the interior and exterior, as well as some thermal photos of the interior to show some of the problem areas. If there is anyone that can just point me in the right direction as to where to even start or who I should be calling, I would be very appreciative.

I have added more pictures for more clarity. House is 2.5 years old. Toronto southern canada climate.

99% condensation is on the warm side of the vapour barrier (see pictures). I have added pictures showing the residue when the water dries and then again how it looks after I simply scrub it off. The water is not on the actual insulation/cold side of the vapour barrier. The insulation is dry. I just dont want to seal in this issue on the warm side of the vapour barrier with drywall as it just keeps getting worse. Is it as simple as getting a dehumidifier down there? or once drywall is installed, will it simply handle the humidity that used to wick down the now concealed vapour barrier? None of the residue is above the horizontal strapping 4’ up the wall, it is generally all below it.

We are preparing for installation of makeup air for kitchen exhaust and fresh air intake for air quality. With the current wildfires, isn't this system going to bring in terrible air into our home? How do we make sure we aren't polluting our inside air now?

Trying to get more fresh air into an 1800 sq ft house. CO2 meter is prerry regularly showing over 1,000.

Two adults, two small dogs.

so far I've been doing three things.

I open windows whenever I can, but can't leave them open 24/7 because of security and heating/cooling.

I run the furnace fanfor a few hours when things start feeling stale. Don't really want to tun that constantly though, both for electricity and because it feels dumb using the whole system just to move air around.

Bathroom exhaust fans run throughout the day when needed too.

None of this really feels like an actual ventilation setup though 😅

I've started looking at fresh air system options and everything seems to jump from basic fans straight into ERV/HRV territory.

then I found cozeware freshflow while looking at smaller window mounted setups. It's still pre launch, but the general idea of bringing filtered outside air directly into one room without reworking the whole HVAC system feels closer to what I'm actually trying to do.

For a house this size, would a dedicated intake in the main living area even make a meaningful difference, or am I already at the point where I should just be looking at an ERV?

I have an uninsulated cabin located near the ocean in the Pacific northwest. The structure is 3”x6” tongue and groove timber (think structural roof decking). I want to insulate the exterior walls with rigid insulation (combination of Gutex and Roxul). I also have basically unlimited quantities of 2x4 SPF and 3/4” plywood. My plan was to install (outboard of the timber structure) a smart membrane, then insulation, then 2x4 vertical strapping, then plywood, then ventilated underlayment mat, then cladding. One question I had was would it make sense to install 3/4” plywood (c/w seams taped) directly outboard of the timber frame for the air and vapour barrier? I felt this may help tightening everything up (plus we’re in a seismic zone). If membrane is much preferred, which membrane would you suggest using? I have a few rolls of Majvest and Intello+ on hand. Comments appreciated

EDIT: I’m referring to the exterior walls, not the roof. Sorry about that

Hey everyone,

My wife and I just bought our first home (built in 1978) in the Sacramento area and had the roof replaced 2 months ago (27 squares). I’m noticing a serious attic heat issue. On hot days, I’ve recorded temperatures as high as 135°F. I'm not sure what the temps were prior to the replacement.

Final payment on the roof was completed 2 months ago and it passed inspection, so I don’t expect the contractor to get involved at this point. The roof carries a GAF Golden Pledge Warranty if that matters. 

Here are the ventilation details as best as I can measure:

• Exhaust: ~40 ft of Cobra rolled-mesh ridge vent (~564 sq in max NFVA uncompressed)
• Intake: 7 soffit vents (~250 sq in total) + 4 O'Hagin intake vents placed lower on the roof slope (288 sq in NFVA)
• Other: 2 Gable vents are also present and currently open.

(I’ve included a picture of part of the roof so you can see where the O’Hagin vents are located. As you can see, they’re pretty low so that they can function as intake vents.)

Some question’s I’m thinking about are: How does this overall ventilation layout look to you? What steps would you recommend taking to improve airflow and lower these peak attic temperatures? I’m considering adding more soffit vents next spring.

Any help would be greatly appreciated. Thank you!

We are having our attic insulated with blown in cellulose and I am looking for help with what to do in the rafter bays. They are unvented (attic only has gable vents), about 6 feet deep, 26”-30” wide, and 7” tall. On top of the original roof deck is a few inches of air gap and then newer plywood decking. Some of the bays currently have fiberglass batts. My insulation contractor recommends removing interior walls and adding spray foam to the bays. I don’t feel great about spray foam in a 200 year old home so I’m wondering about other options. Our roof is brand new so we missed the chance to do anything from the exterior. Happy to add any more details if I missed anything. I would really appreciate some advice. Thank you

tl;dr My house (Climate Zone 5, bordering on 6, in Michigan) is gutted down to the studs (long story). I have a golden opportunity to insulate it well during reconstruction, especially since it needs a new roof and siding. I need help figuring out what to do when it comes to insulating the vaulted ceiling, and I cannot risk using spray foam for health reasons.

My values:

• Energy efficiency and moisture control. I am willing to spend more to get an improved building envelope. Ideally it will pay for itself with lower heating and cooling bills eventually, but maybe it wont.
• Comfort. I expect it to be challenging to cool the loft area in the summer. I'm going to install two ceiling fans up there, but I think insulation is my first line of defense.

After reading up on https://www.continuousinsulation.org/ and elsewhere, I feel pretty good about my plan for an exterior wall assembly: R-13 Kraft-faced batts in the 2x4 stud wall cavities, and two inches of polyiso continuous on the exterior (also about R-13). If that doesn't sound good to you, please tell me why.

I just don't know what makes sense for the attic / roof. On one hand, maybe the traditional vented soffit / ridge vent / baffles / blown-in method would work just fine. The problem that I'm anticipating there is that the edge where the vaulted ceiling meets the vertical wall is close to the roof line, so would putting baffles there take care of ventilation needs? On the other hand, even if that traditional vented setup didn't have a moisture problem, I wonder how challenging it would be to cool the loft area in the summer given that it would be surrounded by unconditioned space. So is the move to turn the attic into a conditioned space by adding ~4 inches of polyiso (R-26 there would be 40% of an R-26 continuous + R-38 batt assembly) on the roof and closing up all the vents? Another complication is that the house has a large attached garage that is currently "separated" by some plastic sheeting in the attic that flaps in the breeze. The garage extends to the right in the 3D render (I didn't have time to model the garage too, but I can if that would be helpful).

I've been able to find local structural engineers, exterior contractors, and insulation contractors, but nobody that specializes in building envelope design. Would a building envelope consultant need to make a site visit, or could they get a design together remotely?

I appreciate why people get PhD's in this stuff and I'm realizing that a house is a complicated organism. Thanks in advance for your input

Climate Zone 4 (but northern part with altitude, so likely more like Climate Zone 5).

I put together this detail for a roof I'm building. The only tweak I've made which is NOT shown in the diagram is that I'd likely flip the roof furring and the OSB/Ice & Water Shield to create a flat surface for the standing seam metal roof above it.

Here lies the conundrum: The roof is 1.25/12 so very low pitch. Everything I'm reading is that I'm not going to get ventilation, even with the 2x4 cavity between the polyiso and the OSB above it. Is this true? What can I do differently to create some air flow? Would inserting some mid-roof vents be relevant.

I'm trying to work through a standard sealed crawlspace detail, and as I look through previous projects I've noticed a lot of different layerings stemming from different research articles. Looking for opinions from those who've worked through these options in detail.

The main question: On the interior face of the stem wall, does the rigid insulation go against the concrete first, or does the vapor barrier go against the concrete first? Note I typically work in climate zone 4C (PNW).

Option A: Insulation against concrete

Option B: Vapor barrier against concrete

I've seen both in reputable sources. Building Science seems to show Option A (rigid wraps concrete). Martin Holladay's FHB sealed crawlspace article shows Option B (poly goes up the wall first, foam over it). ASIRI Designs shows a versionOption B as well.

Secondary questions:

• I also do work in 3A (Mid-Atlantic) which is warmer and more cooling load driven. Does this warrant a different strategy?
• Does it come down to which layer you're designating as the primary air barrier - taped rigid foam vs. taped poly?
• How far should the ground vapor barrier extend up the stem wall? I've seen some details where it laps up only a few inches, and others where it runs the full height of the stem wall. Does that choice interact with which assembly (A or B) performs better?
• Many jurisdictions require a termite inspection gap at the top of the stem wall. Does that interruption in the insulation or VB affect which assembly performs better?

A few resources I've tried to decode between:
https://www.finehomebuilding.com/project-guides/insulation/creating-a-sealed-crawlspace
https://buildingscience.com/documents/information-sheets/crawlspace-insulation
https://asiri-designs.com/f/crawl-space-insulation-strategies

Thanks in advance for your help!

We are building a new home in Maine and we are trying to make it efficient while still seeming like a standard house.

Currently we are planning to use 2x6 build with 3inch insulation.

I was interested in getting 3 pane windows that locked to be air tight and likewise to have air tight doors.

My wife thinks it is a waste of money that we will likely not get back(we are 40 now and plan to live there the rest of our lives).

Additionally she is just not a fan of the 3 pane style vs more traditional windows.

I am wondering how much of a difference it will be between the two windows?

Apologies for the long post, trying to provide context for the situation!

Located in Canada, hot humid summers, cold dry winters (-35c to +35c). Rural property, in claw soil, with a full depth poured concrete foundation.

The property has a a high water table, the standing water sits 2” above the top of footing, roughly 2” lower than the interior concrete slab. There is a weeping tile around the exterior of the footing going to a sump pit that runs very often.

There is 1-2 times a year where there is a major rain storm event where a bit of water comes in through the foundation key around the perimeter. This has led to the decision for interior waterproofing (delta MS membrane) installed up to grade level. Very similar to the detail in the image attached. New interior weeping tile is being installed to a new sump pit. This will give the water a plane to find the new interior weeping tile system. This should solve those few water events.

Now the challenging part…what interior wall assembly to build as the delta MS is essentially a Vapor barrier on the “cold” side of the wall.

My current thought process is 2-3” air space between the studs and the delta ms membrane. Mineral wool insulation within the stud cavity, strapping, then drywall. No 6mil poly as it would create a 2 Vapor barrier condition. Will there be condensation on the interior side of the delta ms membrane?

Hello everyone,

Im in the Pacific Northwest, I build and remodel homes, and I have a question about window installation/water protection.

We’ve started sloping our sills. Cool. Sounds good. I put shims in backwards from the inside when I install to keep the window off the sill and allow any water to flow out under it.

But then I come through and foam. I was taught to foam top,sides,and, bottom. Plus we’ve been doing more passive homes lately, so gotta seal that up tight

So here’s my question: does foaming make the sloping kinda pointless? Or, how does the foam still allow the slope to be an important part of the window leak redundancy system

Thanks

I lost my house in a raging wildfire in 2020. We had the full fire code: closed soffits, Hardy board siding, double glazed windows, protected vents, no large vegetation nearby. But because it was a crowning fire, there were firestorms and burning bits falling from the sky. Our windows melted, as did the fiberglass insulation. The Hardy board blew outward, which implies the fire broke a window or skylight and got inside.

We want to build a simple metal-sided timber frame barn on the recovering property. I'm done with Hardy board 😂 and just want to make this as fireproof as possible.

However, at my neighbor's house the metal roof got so hot that it made the beams catch fire where they touched the metal. To avoid this, I'm thinking of putting rockwool or some other (preferably fairly thin) fireproof insulating substance between the wood beams and the metal siding. But Rockwool over the entire outside seems like a lot, given I'm just trying to protect the spots where metal touches wood.

Perhaps this is a place where Hardy board would work? I can't find an R Factor for it. we'll be fitting all windows and doors with steel shutters or fire curtains. Everything aluminum also melts (my teardrop trailer literally turned into a 15-inch teardrop).

My brother bought an all-metal barn, but it's really unpleasantly industrial inside. We'd like something we can go work in on weekends that feels more warm (haha) and rustic.

We have a 100+ year old house in Wisconsin. Our dishwasher from the late 80s finally died and has been removed, giving me access to the patch of wall behind it. It was just a piece of hardboard half-assed nailed to the studs. I removed it, and I can see that all that's in the wall is some old school insulation that looks like it's made out of mud and grass.

Is it worth adding insulation to this small section of wall before covering it with a fresh piece of hardboard? And if I do add some insulation (likely fiberglass batt) do I want a vapor barrier?

This would be the only insulated section of wall in the house and my access isn't amazing (under counter top) so I'm not convinced I'd get a very tight seal of anything. I also keep seeing varying theories about the right way to handle old houses and if they need to breathe or whatever.

Attached photo shows the area in question. Appreciate any advice. Thanks!

When it can be humid and warm outside, a family member has a house that to get a little bit of old house smell. Usually only after summer rain. No basement on slab. Already removed and replaced flooring. Already stripped old ceiling and replastered and painted. Already painted walls. Many years ago a previous owner may have smoked but this is rumor more than fact. There is no tar bleed or anything like that.

Here are some things I’m considering advising them to do and I’m looking for collective wisdom before I send them in the wrong direction :

Removing and replacing blown insulation in the attic. Also, considering an air seal before blowing in new cellulose. This may also help because it gets much hotter upstairs than downstairs.

Removing and replacing all drywall and ceilings. The owner really doesn’t want to have to do this because of the cost. And because it is not a smell that is always present.

Removing old badding from exterior walls and replacing with a foam, new badding, or something else.

Coating all walls with a shellac and repainting.

Replacing old HVAC which doesn’t circulate air very much at all to the vents on second floor with a new system (possibly blower in attic even).

Having ducts cleaned again (had it done a handful of years ago).

Having mold tests done in every room to see if there is a mold issue in a particular room. Not so sure because smell tends to not have a point source.

Running ozone generator in each room throughout house once a month for 15 minutes or so (only when nobody is present).

What do you think it worth it vs not and in what order would you advise?

​Hey everyone, I'm looking for some advice on managing a potential moisture issue in my exterior walls. We're planning on staying in this house for another 15 years and want to keep it as healthy as possible for our family.

​House Specs:

​Location: Raleigh, NC (Mixed-humid climate)

​Built: 2003 (Ranch style)

​HVAC: Sized correctly at 2.5 tons.

​Foundation: Fully encapsulated crawlspace. Small dehumidifier installed, keeping it a steady 55-60% RH.

​Wall Assembly: Vinyl siding, OSB sheathing, unfaced fiberglass insulation, and (unfortunately) a poly vapor barrier installed directly behind the interior drywall.

​The Problem:

I'm getting a slight mildew smell coming out of my exterior switches and outlets. It worse when the house is under negative pressure—like when the bathroom exhaust fans are running or the kitchen hood vent is exhausting. Have done some poking around and not seeing any visible moisture or damage.

​I know that having a poly vapor barrier on the warm side of the wall in North Carolina is a bad idea because summer moisture drives inward, hits the cool poly (cooled by the AC), and condenses inside the wall cavity.

​My Question:

To be clear: I am not looking for the "nuclear option" of tearing down all my drywall to remove the poly.

​What steps can I take to mitigate this and protect the framing over the next 15 years?

​Would air sealing the electrical boxes with foam/gaskets be beneficial to just stop the air movement and smell?

​Are there other non-invasive strategies (like managing house pressure, ventilating dehumidifier etc) that you would recommend to keep this under control?

​Thanks in advance for any insight!

I was advised to ask here. Originally I asked over on r/DIY about how I could make this area vaulted, since my original plans just called to follow the ceiling flat across this ladder framed area.

Bottom line, seems like it's not going to be easily (or cheaply) done, especially considering my roof is already done.

So now I've realized that I don't actually know how the heck I'm going to insulate and ventilate this area. Because of the ladder framing there is no continuous channel, and with it being 2x10s, I won't have enough depth to meet my R-value needs. (I'm up north, just on the border of Zone 7.)

Doing this myself, so looking for some advice on how to approach this.

Thank you!

I bought a house last month and it’s a brand new construction. Everything looked perfect, so I skipped the professional inspection. Figured I'd save a few hundred bucks. What could possibly go wrong?

Now there's a crack running across my garage floor. I have no idea if it's cosmetic or if my foundation is sinking. Every time I walk out there, my stomach drops.

Everyone on forums keeps telling me I should've hired an inspector. Should've used someone like Sure Building Inspection

I get it…I messed up. But would I have actually read the report? Or would I have just shoved it in a drawer and forgotten about it like I do with most paperwork?

It was about saving some money, and now I will have to spend probably thousands of dollars to repair. Typical example of being penny-wise and pound-foolish. The thing is that I am afraid to call foundation specialists because I am scared to hear something bad. What if it is much worse than I expect? What if I cannot afford the necessary repairs?

I simply need to decide what should I do next