ptc@home 3: Rigid Styrofoam Insulation and Drainvent Rainscreen

[@timgleason2527]

Always nice to see high-performance building techniques done in a “normal” and affordable way!

[@ProTradeCraft]

Thanks Tim.

[@kurtwelday8465]

That music is dope! Thanks for making this so informative and entertaining. Watching 2 years later.

[@ProTradeCraft]

Glad you enjoyed it, Kurt, I'm digging the zero energy bills!

[@AK-tf9kd]

Cannot wait to follow you through this project. I was looking for some local contractors that do this but none do. I will probably do it DIY on my own house.

[@ProTradeCraft]

It is astounding to me how many contractors do not know what this is. I have been covering it here on Protradecraft for seven years and was covering it at Fine Homebuilding for a decade before that. It seems like malpractice to not know what the current science is saying about your product. I mean 17 years is a significant chunk of any career to not know what improvements were coming through the code cycles.

[@claireh.7605]

@@ProTradeCraftI have a house in MA. Can I do this to my house?

[@MarlonJoseGE]

Loving the music too!! Nice.

[@ProTradeCraft]

Thank you. We usually get complaints about the music.

[@Mark-vx5dt]

Could you elaborate on your window flashing detail? I saw you had a typical peel and stick flashing under the window and tied into your tyvek layer. However after the rigid foam was added, it looked like you added a second flashing that overlaps the foam, but how is it installed back to the window? Is it just run up against the window and adhered over the first flashing? Or does it get lapped under the first window flashing somehow, layered like shingles?

[@ProTradeCraft]

A little bit of both, depending on what your wall looks like. If the windows have already been replaced, you can not tuck it under the window. Sealing the Tyvek is more for air sealing than water management at that layer. The second layer is water management, extending from the window out over the foam. Hope that helps.

[@kenchapman6316]

If water gets through to the backside of the insulation (maybe through your window bucks), are you concerned with it at all getting trapped in your coil stock at the bottom?

[@ProTradeCraft]

No. The coil stock bug protection is taped tightly to the face of the Styrofoam

[@claireh.7605]

Haha so I can copy and do exactly this in Massachusetts?

[@ProTradeCraft]

Pretty much. This house in in North CT

[@patpatpat999]

What siding doesn’t require furring strips over 2” of foam board?

[@ProTradeCraft]

siding with long nails.

[@bellsback]

@@ProTradeCraftHi there thanks for taking the time to make a video on your project. Question: Do you think installing drain vent rainscreen over poly iso (astm-c1289type2 class1 grade1)with Compressive Strength of 16 psi be an issue if HardiePlank will be nailed through both layers ? if yes would (grade2)20 psi work ? correct me if Im wrong the product you are using is 25 psi compressive strength ? Im worried about hardiplank being wavy when compressing drainvent to rigid insulation. I like the idea of having a gap between the siding and the rigid insulation without having to nail furring strips. The house your working on in the video... what is the main source of heating ? electrical baseboards or forced air natural gas Did you add any makeup air or HRV/ERV when project was complete ?

[@claireh.7605]

Is it okay if I don’t have continuous insulation into roof and on basement foundation?

[@ProTradeCraft]

Yes, but continuous is better. On this house, I just did the walls, not the roof, and it reduced energy use by at least 40% right off the bat.

[@peterdesmidt8742]

I'm sure I'm not understanding something, but isn't the Styrofoam impermeable to air and water? Doesn't this mean that any moisture from the inside of the house will go through the Tyvek house wrap but hit the Styrofoam and get trapped?

[@ProTradeCraft]

It is basically impermeable to air and moisture, and the thicker it gets, the more impermeable it is. So, yes, moisture from inside could find it's way to the backside of the wall sheathing and diffuse through it to the backside of the Tyvek, diffuse through that and hit the backside of the foam. However, according to physics, moisture goes from more to less, so unless it is very wet inside, the moisture will likely dry back inward. If it is THAT moist inside, an exhaust fan is certainly in order. The more important piece of that equation, though, is that the vast majority of moisture movement is on air currents, NOT through diffusion. So, with a good installation of the Tyvek and Styrofoam, there ought to be very little air pushing its way through the wall system.

[@bobtoepfer8726]

yes! that is what I thought too! House needs to breath??

[@treystills]

Love your stuff! Thanks for sharing. Curious...anti-racist but pro marxist?

[@ProTradeCraft]

Glad you like It. ✌

[@marekwejnar324]

In Tyvek installation guide it says 1. Tyvek wrap. 2 Foam Insulation. 3 Tyvek rainscreen wrap. 4 Cladding. But I guess it fine like this.

[@ProTradeCraft]

There are a bajillion options in the tyvek manual. The detail here was developed in partnership with the Tyvek technical department because it represents one of the scenarios they did NOT already cover.

[@therealSIRBOOM]

Where does one acquire the metal channel?

[@ProTradeCraft]

Bend it from coil stock on a sheet metal brake.

[@MattFerguson26]

1:15 where do you get details like that?

[@ProTradeCraft]

From a LONG career in construction and construction media. That base of wall detail is one I've been covering for decades through Fine Homebuilding, GreenBuildingAdvisor, and now Protradecraft. I worked out all of the details with DuPont's Building Knowledge experts as well as some top-notch builders/remodelers.

[@morninboy]

Styrofoam off gasing is 1500 times as bad as CO2 regarding GHG's. Please use rigid mineral wool AKA Roxul comfort board

[@ProTradeCraft]

Agreed that m,ineral wool is better for GHGs. Styrofoam now has a zero GWP rigid insul;ation, which you can see in the forst episode of Building Resilience season 3

[@sidingmaster]

That siding will fall off! He didn’t hit any studs and that so called bug screen will get dust in it and prevent airflow

[@ProTradeCraft]

Disagree. The wall sheathing is 3/4 inch solid lumber, and almost all siding products are rated for 7/16 OSB. Not sure where all the dust id going to comer from hiding behind siding, but... What's your preferred system for exterior insulation and rainscreen?

[@scorpio6587]

Terrible music choice.

[@ProTradeCraft]

HA! see comment above! Thank you.

[@ronwest7930]

The helium-using person talking in the background was distracting.

[@ProTradeCraft]

No helium balloons were injured in the making of this video