r/buildingscience

Hello! Any thoughts on installing a peal and stick WRB (weather resistant barrier) (maybe ProClima Adhero 1000) against the subfloor that is accessible in a 1949 pier and beam home?

The problem is that there is a lot of air leakage into the crawlspace. Here in Austin TX, the crawlspace gets so much leakage from the conditioned space that it is just as cold as the conditioned space. The problem is that in this 1800 square feet home, the subfloor is made from diagonal tongue and groove solid wood boards (great wood and in great condition). The floor board (on top of the subfloor) are themselves solid wood tongue and groove boards but oriented different and with different shape per board (smaller). The only barrier between the subfloor and the floor is tar paper. In some areas of the house there is no subfloor and the floor boards are installed directly to the joists.

I was thinking something like Adhero 1000 would allow the wood to breath in the case that there were ever a water leak in the conditioned space as well stop airflow or conditioned air leakage.
I was thinking I could order a roll and cut out pieces I could place in between joists. Ideally, I’d redo the entire house’s floor but the house is currently being rented out. I mainly want to improve the comfort of the house by reducing air leakage from the conditioned space to the outside. Any thoughts on this approach?

I have owned my house for a couple years now and since i purchased it i have never had floor insulation in the crawspace, my crawspace is completely blocked around but once get in obviously it’s just the exposed subfloor above you. So would it make sense to put insulation under the floor and would it make a difference in the wintertime. I live in WVA and it gets pretty cold at times and i just wanted to see if it is justifiable to buy the insulation and put it in.

My apartment gets stuffy pretty quickly, but opening the window doesn’t really help.

It just brings in outside dust, pollen, traffic noise, and whatever else is floating around.

So now I’m stuck choosing between stale indoor air and everything that comes with “fresh” air from outside 😭

Anyone else dealing with this?

Fresh civil engineering undergrad working at a small facade consulting firm. Still kinda unsure whether it is the right path for me as I’m straddling between structural and a building science career. Do lots of THERM modeling, Curtain wall shop drawing review, energy code compliance stuff, some wind load calcs.

Structural is a more “traditional” path that might require masters but seems more technical in nature. On the other hand I do like how building science is a mix between architecture and engineering. It is probably difficult to do both building science and structural and probably wouldn’t be beneficial for my career.

I feel as a civil engineer undergrad it’s a little bit of a misfit, as lots of building science is based on mechanical thermal principles. It seems structural getting a PE is required, but I feel it isn’t as necessary in a building science career?

Any insight would be appreciated!

Hello all! Ok! Looking for some guidance, hoping i can explain this in a way that makes sense.

My house is 161 years old. The chimney was unlined and the water heater vents into it. So...I was a good little homeowner, saved my money, had the chimney lined, capped, and 2 draft holes in the chimney filled where the water heater connects. 2 days later there's a leak somewhere in the chimney area coming into my upstairs bathroom. Chimney guy is super cool, comes back out, can't figure out what the problem is. Says the flashing around the chimney is really not ok, and that the roof is hinky. I have 5 different roofing companies come out. All say the chimney needs to be demoed below the roof line, B vent installed, need new roof because whoever replaced it last was drunk.

The furnace and the chimney are VERY close together in the basement. Almost touching. Something is dripping from up high in a dark cavern that no one can see.

My question is...

Could the act of lining the chimney and filling in those holes have caused condensation that can't escape from the water heater in the chimney? WHAT could be happening here? At first I thought the ducts for the HVAC may have been dripping, but now I'm not so sure! I have since put a heavy duty commercial dehumidifier in the basement and the dripping persists. The leak also shows up in the plaster upstairs even if it hasn't rained (the chimney area is tarped, but of course the whole thing isn't tarped because the water heater vents through the top).

Any help would be greatly appreciated! The water is starting to soak the beams below it, and who knows what damage it's causing in the house.

I've had roofers, HVAC guys, and a plumber all come out. Plumber is convinced that once a B vent is installed the issue will be resolved...buuut...that just doesn't make sense to me. Help!

Hello all! Really, really needing some help here. I have a very, very strange situation. Hoping i can explain it in a way that makes sense.

Finally saved up my money and had my chimney lined since my water heater vents into it. Chimney liner and cap. 2 days later it rains like crazy, and there's a leak in my upstairs bathroom ceiling/wall where the chimney is. Chimney guy is cool, comes back, dumps a bucket of water in the area, water starts coming. He has absolutely no idea how it's coming in, and says he isn't a roofer, but the roof is real weird. He is very apologetic and feels responsible, but also can't figure out what's happening. He also filled 2 old vent holes in the chimney in the basement with concrete.

I set up appointments with 5 different roofing companies. Each one says the chimney has to go, because it is "fucked." Also quoted for a new roof (oh joy) because whoever installed the last one was clearly drunk (photographic evidence was provided. Of the roof. Not the drunk guy). Chimney is to be demoed just below roof line and a B vent will be installed for the water heater.

At the same time the humidity levels in my house are way too high despite having the AC on. The system is only a year old. Dual fuel heat pump furnace situation. 2 ton, 1200 square foot house, Southern Ohio, humidity, I know. Basement humidity is generally around 64%, inside varies from 60-63%

HVAC guys come out and say everything is working as it should be, but they DO really hunt for what could be happening here. They lower the blower speed a little, change the pitch to the condensate drain. And discover SOMETHING dripping from SOMEWHERE above the return that just goes straight up into no man's land. The support beam below is wet from whatever the fuck this drip is.

The furnace and the chimney where the water heater vents are SO close to each other that they're pretty much touching. There is a bathroom up about where the drip is coming from, but there's no obvious plumbing in the area and I haven't noticed anything weird toilet or otherwise related, and can't even see where the freakin plumbing would even be.

The only kind of contractor human I haven't had out yet is a plumber. Initially I called about water heater options in order to just NOT use the chimney at all anymore, but now I'm wondering about leak detection.

Does anyone know what the chimney guy could've possibly done here? What the hell could be going on? It's impossible for me to photograph the drips because it's up in a dank, dark cavern.

The house is old as shit (1865. I know, i KNOW), but it had modern AC for YEARS before we got here. It isn't like we're converting her over into modern times or anything! And shit was fine last year until the thing blew up! I have replaced damn near everything in here except for the water heater. I'm considering selling at a loss because I can't financially keep up with the catastrophes. I'm still here because i love my neighborhood, and if I sold I wouldn't be able to afford to continue to live in this neighborhood. How fucked up is that?

Help? Please? Maybe? Any ideas? Thoughts?

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 just had a home science guy come to the house and and test my HVAC and attic fan and see what the negative pressure was or would be.

I suspected with the attic fan I had high negative pressure because when the attic fan turned on the humidity would rise in the home, along with the temperature.

Attic fan genartes around -6 pascals when it's running in my home .

The central air conditioning, air handler in the attic, return on the second floor above stair case, with the doors closed to the bedrooms have a out -5 pascals when the doors are open it drops a little to about a -3

My attic was recently sealed and did insulation. I also ran new duct lines in the attic and did duct sealing.

The guy just told me like 100 different things I could do and left. Didn't really write anything down. He was absolutely awesome at testing but terrible at options 😂 so that's why I'm here wtf should I do.

I have an attic that's buried in insulation and difficult to work in. Is this a common problem?

Hey y'all. I'm based in Revelstoke bc, we are zone 6 on the bc building code. Our climate is an interior rain forest, so it can be very wet at times, but has been very dry in recent months.

I am currently renovating my basement which is a house from 1956 built without vapour barrier or proper drainage around the house. We have installed gutters around the whole house in the last year to help mitigate moisture issue.

When I tore down the one room that was finished in our basement, I removed vinyl planks that were installed directly on the concrete for the past 5 years. The slab was quite wet with water almost pooling in areas. I have also noticed that any plastic/fabric items left directly on the slab would make the concrete color darken/mold up over time. There are no cracks letting water in at all. It seems to be just moisture coming through the slab. I also installed a sump pump for the bathroom I am setting up and noticed that my slab is only 2"-4" thick, which explains the issue to me.

Now I am wanting to install flooring (Choosing between LVP, Laminate, Engineered wood floor, and going with tiles in our bathroom).

I have done quite a bit of research and the best product I seem to be finding is a dimple mat as an underlay and laying my flooring above. I have my eyes on DMX 1- Step 2.0 as it is rated for vinyl planks and has a low profile (My ceiling is low enough as it is). I would like to see if anyone has a different opinion on the product I should use or any experience using the same product or something similar? I have also looked into different sealant, but I have less faith in these as I feel like water pressure overtime would probably have the last word.

That being said, for my bathroom where I want to tile. I will most likely need a sealant. I see redguard by Custom seems to be a good quality product for a decent price. Any thoughts on this solution as well?

I know that my ideal solution would be to prohibit moisture from getting under the slab, but this is a very costly and invasive solution.

Thanks for your time,

Seb

TL;DR 1901 house, 2nd flood gutted, foam sealed all gaps, would it be OK to not insulate and then fill cavitites with cellulose?

House: 1901, platform framed. Sheathing is 2 inch think lumber, with wood siding ontop of the sheathing and cement siding ontop of the wood siding. No housewrap etc. 4.5 inch (+/- half inch) deep stud cavities.

Goal: I am not trying to create the most energy efficient house in the world...I just dont want mold.

Situation: 2nd floor gutted for rewire job and now suprisse renovation.

What ive done: I have sealed the gaps with expanding foam to make things more air tight. I was going to put R19 in and vapor barrier but reading online has me convinced that fiberglass insulation will mold and rot my framing - especially becuase the r19 would be compressed.... I dont want to spend close to double on rockwool.

Proposed plan: hang sheet rock, and then blow in cellulose insulation. Would this reduce mold risk?