Would have been nice to talk about the drainage gap with exterior insulation. A lot of the issues that you said the drainage gap helps like drying through the wall can't happen when there's exterior insulation so is the drainage gap less needed in that case?
@@ASIRIDesigns Thanks for the link! I get the idea of having a peel and stick WRB with a texture (or rockwool or other texture material) to have a 1/16th gap for drainage between the WRB and the CI, but where is this water coming from? Surely this is not bulk water getting past the cladding and through the CI? And with only 1/16th gap this is only drainage and not drying so the house would not actually be able to give up moisture through that gap? To actually dry as you said you need more like 3/8" which would defeat the CI from actually keeping the house warm. Once you have CI aren't you required to keep the humidity in the house under control so that it can dry inwards and if that's the case why can't a rigid foam be right on top of the WRB?
@@BenBrandthe water that may collect between the WRB and CI probably enters the assembly through the wall cladding. I've heard estimates that up to 25% of the bulk water that the cladding faces may penetrate that layer, depending on the installation and type of siding. The CI will repel most of the water, especially when working in combination with a ventilated rainscreen, but a fraction of that moisture load will inevitably work it's way between the WRB and the CI. This is why a drainage-only gap is required, a fraction of a fraction of the bulk water is present and to maintain the resilience of the assembly a final drainage opportunity allows the last bit of bulk water to drain. Don't forget that this is a WRB and air barrier layer so controlling interior air moisture should not affect the need for a greater space between the WRB and CI. And even with that in mind, interior humidity management should be included in every mechanical system for building performance, occupant health, and comfort.
My parents' house has a lot of mansard-roof-style siding above brick, and as ugly as that old style is, it makes the house invincible because it's basically a foot-deep rain screen. No matter how badly it's built, and no matter how much it leaks, the wall inside will dry out because there's so much space and it's vented all the way up to the roof. You could leave for 100 years and come back, and the cedar shingles would be half rotted away, but behind them this huge drying potential would be kept, protecting the pine framing from rot. A very practical old style. Medieval and ugly, but practical because of the huge rain screen. Great video as always!
One of the things I have thought about and would be curious know from others here is if the Tuff-Rib profile on many metal sidings is enough to be considered a rainscreen? I believe in Canada it fits code there. From experience that siding definitely doesn't fit tight against the sheathing besides the raised profile sections etc.
Yes weep holes help dry it out. Masonry loves to wick moisture. Without weep holes you can have ice dams behind the masonry veneer in winter. Masonry veneers doesn't usually stop all the moisture from getting behind it. Think the build show has a video where they spray a brick veneer with a hose to show the moisture getting behind it. Below grade weep holes can allow dirt to get into air gap which I see on 100+ year old commercial masonry buildings. Plus below grade needs type m or s mortar. Which wasn't used to build older buildings. Masonry to last needs to dry out or it will get water logged. Seen a lot of masonry fail because it was water logged. Here the freeze thaw cycles will destroy water logged masonry.
@@danddietz Depends on how many weep holes you have at the bottom and if ventilation is provided at the top of the brick veneer. We generally don't consider brick veneers to be fully "ventilated" because of the limited air flow, and therefore they are just drained. Mortarnet and MTI have some good solutions for ensuring drainage and ventilation
what about a roof rain shield for the north like in MI? Is there a preferred method do too this for both non vented or vented roof? Also, Do you have drawings for sale that show roof design for a non vented roof build on a zip home? I can't seem to find any on your site. thanks
So would metal siding, like that used in post frame buildings, attached directly to the wrb layer provide enough air circulation for drying of rain infiltration and vapor coming from an insulated wall assembly?
The explanation of the system is great but man some of the photos are of what not to do. At 2:29 those horizontal pieces that whoever did that work put on are completely defeating the idea of a rain screen or vented cladding. Also it’s really not necessary to have a rain screen for vinyl siding. I suppose it can’t hurt but I just don’t think it’s necessary with all of the air space vinyl has behind it already. And I don’t know what that mess is at 3:25 but it looks like Twisted Tea was involved 🤣
Would have been nice to talk about the drainage gap with exterior insulation. A lot of the issues that you said the drainage gap helps like drying through the wall can't happen when there's exterior insulation so is the drainage gap less needed in that case?
@@BenBrand We actually have a video on this right here: ruclips.net/video/VwUjkSjllPs/видео.htmlfeature=shared
@@ASIRIDesigns Thanks for the link! I get the idea of having a peel and stick WRB with a texture (or rockwool or other texture material) to have a 1/16th gap for drainage between the WRB and the CI, but where is this water coming from? Surely this is not bulk water getting past the cladding and through the CI? And with only 1/16th gap this is only drainage and not drying so the house would not actually be able to give up moisture through that gap? To actually dry as you said you need more like 3/8" which would defeat the CI from actually keeping the house warm. Once you have CI aren't you required to keep the humidity in the house under control so that it can dry inwards and if that's the case why can't a rigid foam be right on top of the WRB?
@@BenBrandthe water that may collect between the WRB and CI probably enters the assembly through the wall cladding. I've heard estimates that up to 25% of the bulk water that the cladding faces may penetrate that layer, depending on the installation and type of siding. The CI will repel most of the water, especially when working in combination with a ventilated rainscreen, but a fraction of that moisture load will inevitably work it's way between the WRB and the CI. This is why a drainage-only gap is required, a fraction of a fraction of the bulk water is present and to maintain the resilience of the assembly a final drainage opportunity allows the last bit of bulk water to drain.
Don't forget that this is a WRB and air barrier layer so controlling interior air moisture should not affect the need for a greater space between the WRB and CI. And even with that in mind, interior humidity management should be included in every mechanical system for building performance, occupant health, and comfort.
My parents' house has a lot of mansard-roof-style siding above brick, and as ugly as that old style is, it makes the house invincible because it's basically a foot-deep rain screen. No matter how badly it's built, and no matter how much it leaks, the wall inside will dry out because there's so much space and it's vented all the way up to the roof. You could leave for 100 years and come back, and the cedar shingles would be half rotted away, but behind them this huge drying potential would be kept, protecting the pine framing from rot. A very practical old style. Medieval and ugly, but practical because of the huge rain screen. Great video as always!
Excellent short form content as always.
Great video. Thanks for sharing.
Hey man, could you maybe do a video on insulating a knee wall? I've seen some videos on it but this channel is the only one I trust
@@shaquileoatmeal7365 Great idea, it's going on our list 👍
One of the things I have thought about and would be curious know from others here is if the Tuff-Rib profile on many metal sidings is enough to be considered a rainscreen? I believe in Canada it fits code there. From experience that siding definitely doesn't fit tight against the sheathing besides the raised profile sections etc.
How does this work for brick cladding? Do the weep holes provide the air flow?
Weep holes in brick are almost always located only at the bottom of the wall, so, they wouldn't provide adequate top to bottom flow
Yes weep holes help dry it out. Masonry loves to wick moisture. Without weep holes you can have ice dams behind the masonry veneer in winter. Masonry veneers doesn't usually stop all the moisture from getting behind it. Think the build show has a video where they spray a brick veneer with a hose to show the moisture getting behind it. Below grade weep holes can allow dirt to get into air gap which I see on 100+ year old commercial masonry buildings. Plus below grade needs type m or s mortar. Which wasn't used to build older buildings. Masonry to last needs to dry out or it will get water logged. Seen a lot of masonry fail because it was water logged. Here the freeze thaw cycles will destroy water logged masonry.
@@danddietz Depends on how many weep holes you have at the bottom and if ventilation is provided at the top of the brick veneer. We generally don't consider brick veneers to be fully "ventilated" because of the limited air flow, and therefore they are just drained. Mortarnet and MTI have some good solutions for ensuring drainage and ventilation
what about a roof rain shield for the north like in MI? Is there a preferred method do too this for both non vented or vented roof? Also, Do you have drawings for sale that show roof design for a non vented roof build on a zip home? I can't seem to find any on your site. thanks
Furring strips are my go to, I install them on the diagonal in most cases.
@@jhippl That works too!
@@ASIRIDesigns Can furring strips be used on the roof as well?
@@keithwingo514 Yes
You mention the rain screen mats being ok for a rain screen but many of those mats (slicker max etc) have only 1/4 inch gap, not 3/8 inch. Is that ok?
Not if you have stucco for sure .
@ what about for fiber cement
So would metal siding, like that used in post frame buildings, attached directly to the wrb layer provide enough air circulation for drying of rain infiltration and vapor coming from an insulated wall assembly?
Will do, liked#2 N Subscribed!!!
@@2point..0 Cheers! Thanks for subscribing!
We've been building like this for over a decade... Where have YOU been?.... Hhhmmm....
The explanation of the system is great but man some of the photos are of what not to do. At 2:29 those horizontal pieces that whoever did that work put on are completely defeating the idea of a rain screen or vented cladding. Also it’s really not necessary to have a rain screen for vinyl siding. I suppose it can’t hurt but I just don’t think it’s necessary with all of the air space vinyl has behind it already. And I don’t know what that mess is at 3:25 but it looks like Twisted Tea was involved 🤣
With regard to vinyl claddings- it really depends on the product. Solid or cellular PVC like Azek you need the gap.