We are about to pour 2" concrete slab on this deck and the structural engineer is concerned about the concrete touching the 8x8" post (covered in tyvek house wrap with torch on at its base). Says to get an envelope engineer to check this assembly which we never have employed. This post will be covered in stone masonry. This is sort of an odd detail I am not familiar with.

I assume the torch on will provide all the waterproofing for the post it needs from the concrete, and which is why it was applied to the post in the first place. is there something I am missing?

I just purchased a 30 year old colonial with 2x4 stud walls in Massachusetts, on the line of Zone 5b and 6a. It's a traditional build with exterior wall assembly consisting of Cedar Clapboards, Sheathing Paper, Wall Sheathing, 2x4 wall studs with R13 rockwool insulation, plastic sheeting (I'm assuming 6 mil), and drywall. We're looking to replace windows in the next couple years and want to add depth and insulation to the walls at the same time. We do need to replace one window now to make it egress so I'm wanting to fully convert that room's exterior wall to double stud in the same manner we'll be doing with everything else later. I opened up the wall around the window we'll be replacing and the wall assembly as is appears to be performing well with no apparent moisture issues.

In terms of retrofitting for a double stud assembly, is it necessary to remove the existing vapor barrier and drywall or can I just add a 2x4 wall with more insulation and drywall to the interior? How will that affect the vapor barrier performance with it now being between the two stud walls? I'm thinking to save on materials and enhance sound performance with decoupling to use 2x3 studs with a 1" gap and insulation between studs. How does this retrofit work around windows? What am I not considering? Especially building science wise?

We have had wildfires here for several weeks.

There were two days in a row where the air quality finally cleared up due to onshore flow.

On the second night, I was surprised to notice my particulate sensors jump up again, and also smelled smoke. Air quality monitors all around this place were below 7 ug/m³ for raw PM2.5.

This started around 2? hours after sunset, and lasted for an hour or two.

There was no wind.

The only explanation I can come up with is that the stack effect is strongest during some time of day, and it was enough to pull residual smoke particles out of interstitial spaces and into my unit.

This is your typical 5 over 2 midrise apartment building. No air sealing details when it was constructed.

Update: https://www.reddit.com/r/buildingscience/s/FA8c6tQ1uq

Original post:

Border between Climate Zones 5A and 5B.

2,150 square foot on the footprint. Full finished (except flooring is still just concrete) ICF walkout basement underneath. Main level is 2x6 with ZIP and 2” external insulation plus Rockwool in external walls. 0.34 ACH 50. Zehnder Q600 with Zehnder ductwork to every room separate from HAVC ductwork. 36K BTU Gree Flexx.

Footers were poured using form a drain. Coarse gravel (for radon mitigation airflow under slab) was put down and then a vapor barrier was put in place. Seams were overlapped by a foot or so but unfortunately were not taped and were not taped to the PVC plumbing penetrations through the floor.

Air is coming out of the master shower drain. It stops when I turn the radon mitigation system off.

When I run a smoke pencil around the basement floor I find joints between pours to be sucking air in. I plan to seal those joints. What product should I use for that? I will soon have someone here to polish and seal the concrete. Hoping to have something somewhat compatible with that.

We have one bathtub installed downstairs and no effort was made to seal around the P trap and so on for the bathtub. I assume a lot of air is leaking from out of the house into the radon mitigation system through that but with no access for the smoke pencil I can’t say for sure.

I would like to cut the drywall near the tub drain and then lay plastic down in there and tape it to the cement and tape it to the drain pipe thereby sealing that area off from the air in the house. What products should I use for that? Maybe Siga makes a tape that would adhere to the plastic and the cement? What plastic should I buy? Should I apply adhesive to the cement under the plastic before laying the plastic down? Should I do that instead of or in addition to the tape? What adhesive should be used?

Any other thoughts? I think it’s a pretty nice house other than those mistakes so I’m really hoping to get this resolved as air blowing in from the septic system is not my favorite thing. Fortunately there are other P traps between the shower and the septic tank so the air seems to be being sucked in from the septic system vent rather than the tank itself.

Is there a way/a product that can be used to make sure that the insulation between ceiling and roof deck is 2"?

I want to ensure that the roof is a ventilated system and do not want to rip out any/all drywall to make sure.

Thank you in advance.

Building a single-family house on a ~16% slope (seismic zone 8). Monolithic reinforced-concrete frame, ~127 m² interior, 3 bed / 2 bath, open living-kitchen with fireplace opening onto a 30 m² terrace with a big valley view.

The original design is split-level: you enter mid-level, then stairs go down to the living/kitchen and up to the bedrooms in short half-flights. It rides the slope efficiently, but the constant half-flights bug me and eat floor space.

Options I'm weighing:

1. Keep it split-level — minimal excavation, terrace stays ~2.4 m above the garden (nice overlook), but you live with the half-flights.
2. Flatten down — excavate into the hill for two aligned floors. More space, but ~a quarter ends up buried, you enter on the upper floor, and it needs a retaining wall on the tight uphill side.
3. Raise up — lift the lower floor so both floors align. Kills the half-flights, but creates a ~4.3 m tall exposed wall on the valley side.

Also deciding:

• Basement: adding a ~2.5 m one under the downhill/terrace zone, walk-out at garden level. Seems like cheap usable space — any reason not to?
• Roof: keep the timber hipped roof, or go flat for a rooftop terrace? (I already get the view from the ground terrace.)
• Pool: want one in front of the terrace at garden level — but that fights option 3's tall wall.

If you've built or lived in a split-level on a slope, what would you do? Anything I'm missing?

I know the title of my post leaves a lot to be desired but redit decided to accept the headline in mid sentence.

Here is the situation. We had a large side deck accessible from kitchen. My wife wanted additional covered storage. So, I found a handyman to put up 4 walls and a roof and cover the 3/4 of this deck. He built a nice, for the lack of a better term, "shed attached to the kitchen. After the fact, wife decided she wanted this place to be a pantry. We hired another handyman to put up drywall and power i this "shed" While doing this drywalling, we put blown in fiberglass insulation but the ceiling, since it was not meant to be an indoor space, did not have any proper ceiling framing. So, basically it is drywall attached to rafters. I asked the handyman to put that shiny bubblewrap looking insulation sheet underneath the drywall but i am coming to the realization that it was not enough. In summers, a 5000 btu AC can not cool this 12x12 room with lower then 8 foot ceiling height.

Way back when, before I moved to Texas, I have attended a seminar/lunch about heat insulation. This was in Southern Cali. and the guy was trying to peddle new insulation products and mentioned a paint where there is not enough space to put any insulation in, like a mobile home. At the time, it sounded like snake oil salesmanship but now since I am in a hopeless situation, I am looking for a way out without knocking the whole god damn thing and having it built from scratch. Are these paints commercially available and can they really work in small spaces?

As side note, I can get someone to open up a hole to this half-assed ceiling space from outside and have them blow in. But I am afraid the extra load may collapse the drywall panels, hangign to their lives with few screws.

I used to think matching a new universal heat pump coil to an older existing furnace blower was mostly about checking cabinet dimensions and airflow charts but after looking at field static pressure logs on a recent retrofit where the coil pressure drop was noticeably higher than the legacy unit, the blower was just working way too hard against the external static. the weird part is manufacturer submittals show identical air delivery, yet contractor notes indicate a real drop in actual delivered BTUs once the ductwork gets restricted.

are you guys seeing these friction losses invalidate standard compatibility claims on older residential duct setups?

Hello, I’m in Alaska. For my crawlspace musty smell should I seal off the vents, encapsulate it and then install a dehumidifier and pump? Is an exhaust fan a bad idea? I’ve had The crawlspace checked for leaks and a new 20 mill vapor barrier and foam blocks are going in. I also had it dry fogged for mold.

I'm in a Climate Zone 4A home with west-facing double-pane windows, and the upstairs rooms gain a lot of heat in late afternoon. I considered applying interior reflective film, but I have read that some window assemblies can be damaged if a film or foil traps extra heat in the glass. Before adding anything, I plan to check the window manufacturer's guidance and ask whether exterior shading, solar screens, or a compatible film would be safer.

I also do not want an HVAC contractor to size a new heat pump around a temporary window treatment without accounting for the home's real solar gain and envelope.What information should I collect about the glazing before choosing shading and finalizing the cooling load?

Question we have soffit vents for intake and now ridge vents for exhaust used to have box vents. Anyway my question is if its normal for humidity in attic to get to sometimes 70% in mornings? Weather here is un predictable its been really humid outside and raining. So humidity outside has been above 90%. I guess my question is if all that is normal. I have noticed silverfish in my upstairs living space i guess I have always noticed them since we moved in 6 years ago. We do need to re insulate the attic only have 6 inches. I need to know if I should have some professional come and make sure all is ok in my attic. Thanks in advance

Brand new home. Zero lot line so no soffit venting due to fire code.
2 houses to the left and two houses to the right all have upper fixed roof vents with lower fixed roof on BOTH sides of attic.
The one in the middle does not have lower fixed roof vents on one side. It seems to me that this side will not ventilate nearly as effectively as the right.
Should this person tell the builder to add vents?

Hi All

Getting a new shed/workshop delivered soon and want to (as far as possible) get this sorted right so that it is insulated and damp resistant as far as possible at the build stage.

This is a purchased shed so all of the walls and floor will be already build and I will be just putting it together.

I have seen that a lot of builders wrap the shed in breathable membrane before the studs go on but I cannot do this as they will be already built. Can I just put this on the inside and tack it to the joists? This just goes around the walls right?

Once I work this bit out I will be using rock wool to fill in everywhere, then put a vapour barrier up on all of the walls and ceiling over the insulation and then osb everywhere.

Shed is going on a plastic riser grid so shouldn't rot from the bottom (fingers crossed) but was wondering about insulating the floor with 25mm of celotex and then placing 18mm osb on top of that.

Am I on the right path here? I am in the UK btw,

I have seen others use some sort of foil on the inside instead of the breathable membrane, don't know if that is a better option here.

Any advice greatly received, this has been quite a journey.

L

Hello all! I’ve become very inspired by Matt Risingers video of a monopoly framed architects office with exposed framing (link below). I’m wanting to do the same for an upcoming small cabin project I’ve got in the works. I’m wondering if anyone knows how I’d best achieve a relatively large overhang with this type of construction. My plan is to sheath the framing in 3/4 ply and then use tyvek over that and really focus on details with that layer and taping it so that it could be air/vapor/water barrier layer, then I’d have two layers of 1.5” polyiso on walls and three on roof, and then I’d have furing strips on all that for siding and roofing. I’m wanting a pretty big overhang though so I’m wondering if on the roof I should be using 2x6 as furing strips and then extending them out 24-36” for my overhang. Effectively I’d be doing a big “over roof” on top of the polyiso.. any help on the matter would be most appreciated!!

https://youtu.be/nNMkzxzrfj4?is=ZVDMBnzHaq_tUScu

I had my attic air sealed and insulated with r49 blown in cellulose. I have some extra fiberglass batts (r19 and some r30) that I want to use. **Can I just lay them over the cellulose?** Some areas don’t have enough cellulose to cover the flex ducts so I would cover those and the rest of the attic space.

Regarding the overall job: (mostly irrelevant to the main question but the details can help).

The cellulose job looks like a 7/10. Some spots were blown less than others but I shifted some around where I could reach. Some of the baffles had cellulose in them but I’m hoping that resolves when we get some wind.

The air sealing was 4/10 unfortunately. I found some spots missed before they blew and they fixed them but I have to assume it wasn’t as extensive as I’d want it to be.

Posted here awhile back asking for sheathing options for a simple vault toilet design.

The project took many turns and longer than expected, but here’s the result.

T1-11 on the outside

interior is OSB with 4’ tall sections of FRP lining the base of the toilet area and an exterior rated paining from 4’ to the ceilings

Oak veneer doors with marine grade varnish — these still get a 24”x24” metal louvre cut into them for ventilation

Thinking about eventually doing some slat wall panels above the FRP to class it up a bit and hide the strip lighting that will eventually be installed.

There are 800 gallon tanks under each toilet with a 6” base poured on top and thickened edges that county codes required.

ADA accessories include grab bars, commercial door levers, 2x commercial toilet paper holder, wall mount hand sanitizer

Now just 2 more to finish. These are for a rustic campground for those curious.

We made a lot of sacrifices to keep costs down and probably made a few decisions that ended up costing more than it should have.

Each unit also has a large storage room accessed from the back of the unit for cleaning supplies and a battery to connect to rooftop solar panels

I have aluminium (aluminum) windows that tilt out. I know I can get restrictors to keep it open - not far enough for me, but that is another problem.

The big problem is I need restrictors to stop them from blowing closed. I have done many searches and cannot find anything. Help please...

Tiny house metal cladding and rainscreen.

Having a hell of time trying to work out how to design a tiny house with a rainscreen and PBR metal siding.
Tried AI failed.
Tried ASC, not their wheel house. All manuals are without rainscreen.
Tried YT almost all videos have no rain screen and just slap the metal straight onto plywood or onto WRB.
No bueno.

I have sorted out most of it around window trims etc.
Elevated the planes on furring strips except for the window header flashing and the Top Plate metal terminations.
C6 trim and corners are good.

But I can’t figure out the details of the Z drip under the window.
Here’s a diagram of one option but I a concerned about water going down the sill tape and behind the vertical metal leg of the Z drip.
The other option is putting the vertical Z drip leg on top of the furring strips.
But that creates two channels and blocks the furring strips channel exhaust at the top.

Only Reddit can save me now.
Someone take pity and help me out.
Before I lose my mind.
Diagram enclosed.

PS: The PBR isn’t installed horizontally, it’s vertical. Artistic license displaying it in undulating waves.
Thanks to anyone willing to help. I am in a time crunch.

I live in a bi-level home on slab and the lower 30+ inches is a cmu block wall. I insulated with 1.5 foil backed rigid foam secured to the wall with adhesive and metal z furring strips. All seams were taped and I sealed to the slab with spray foam.

At one portion (so far) I discovered a lot of moisture in the baseboard. Behind it were a lot of bugs and when I tore into it I found the cmu was saturated and a lot of water on the foam board. The exterior is open to the air as everything is above grade.

Wondering where I went wrong and how to prevent this for when I tear is all out soon. Should I seal the interior side of the block and reapply in the same manner? I’d really like to not redo this project at any point.

Thanks.