Not curtain wall, just zero frame. Are they embedding it into the walls? I've seen videos where you can use angle iron at the exterior of the wall to nestle the IGU into then from the floor it's 100% glass, but there's thermal bridging concerns.
natematt
Mar 25, 24 1:52 am
The options are pretty wide open.
The importance of thermal bridging is partly defined by your application, climate, and how much you care. There are still a lot of applications of hot rolled steel windows with worse thermal bridging issues than the custom angle stuff.
The custom angle stuff freaks me out more from a waterproofing standpoint because it’s relying on some maybe not so good craftsman. You can also do wood applications like you see here, but that has an additional issue with durability. That said, for someone’s personal cabin this seems like a reasonable approach.
Integrating a more standard system into a wall/ceiling/floor can be done, but there tend to be limitations and it can make glazing and de-glazing an issue since most basic systems are not designed to be installed that way.
In this design Cutler is just using single sheets of glass with wood stops and custom aluminum corner shapes.
Everything is 'waterproofed' by the roof overhang and caulking. The building has no insulation.
Wood Guy
Mar 25, 24 10:52 am
It's called direct glazing, popular in "hippie houses" of the 1970s and 80s. A few years ago I replaced several large direct-glazed windows and it was a pain--the sealant was still incredibly strong after 40 years--and I couldn't use my usual flashing details, but it seems to work if you know what you're doing.
Chad Miller
Mar 25, 24 12:03 pm
Hippie houses. ::giggle:: On a serious note - some of that old sealant is almost indestructible and forever viscus. It must be all the carcinogens. ;)
gwharton
Mar 25, 24 1:42 pm
It's also sometimes referred to as "stopped-in glazing". It's the way all windows were made back before industrial mass production made factory window units way more cost effective with better quality control. Basically, the window "frames" are built custom on-site by a finish carpenter (who ideally knows how to frame a window that doesn't leak ... these are in very short supply these days). The glass is inserted into the frame and then locked in place with sealant and/or wood frame "stops". For fixed glass units, this is still a perfectly fine way to build windows, but energy codes won't recognize them for anything except default performance on u values. Operable units are another matter entirely, since (as I mentioned) almost nobody knows how to actually build them from scratch anymore.
Chad Miller
Mar 25, 24 1:47 pm
I've seen a lot of direct / stopped glazing in old MN buildings. The thermal performance of these types of windows (single pane) are absolutely horrible in a heating conditions.
In the right climate, with the right building orientation, and overhangs this type of glazing assembly can work moderately OK.
Wood Guy
Mar 25, 24 3:00 pm
GW, I was going to say that's not how traditional hung windows were made, but on further thought that is one way to describe glazing a sash using glazing putty. (I've made several historic reproduction windows and doors, and restored many others.)
Chad, you can buy double-glazed or triple-glazed IGUs and direct glaze them. That's what we did on the direct-glaze project I mentioned. There is some thermal bridging at the perimeter but no more than on a factory-made, wood-framed unit.
Chad Miller
Mar 25, 24 3:13 pm
Sorry WG - I was commenting on single pane glass like in the Cutler cabin. Double or triple pane glass in a direct glazing assembly work great! Getting the glass out without destroying the wood stops though - yikes!
Wood Guy
Mar 25, 24 6:50 pm
On my project we had no problem getting rid of the wood stops, but the sealant between the glass and the framing was still intense! I felt bad for the glaziers that they gave a fixed price, but happy for my clients, as it took 2+ days for 2-3 guys to change out four windows.
Chad Miller
Mar 26, 24 10:34 am
Eeep! I've seen old sealant like that be a combination of concrete and silly putty - you can't get it off!
Wood Guy
Mar 26, 24 11:00 am
That's a good description.
Chad Miller
Mar 26, 24 12:10 pm
Did we just come up with a way to make super durable buildings? Coat everything with that glazing putty?
I helped my dad re-glaze a cabin with that stuff. I still have PTSD from the experience. ;)
gwharton
Mar 26, 24 12:59 pm
3M 5200 marine sealant is great stuff. I keep several tubes of it on my boat. It will glue anything to just about anything else, with a long-term waterproof bond. But seriously, if you use it for something, don't do so casually. It will be there FOREVER.
Chad Miller
Mar 26, 24 1:40 pm
. . and ever, and ever.
t a z
Mar 25, 24 11:28 am
You can do structural glass installations with IGUs spanning vertically, but what you don't see are the significant head and sill details to clamp the glass in place.
The corner condition would be a mitered detail.
t a z
Mar 25, 24 11:53 am
And, as natematt was aluding to, glass replacement strategies become a significant coordination issue
Le Courvoisier
Mar 26, 24 12:30 pm
Too much glazing. What I do in the woods is no one's business
Chad Miller
Mar 26, 24 12:37 pm
That's not the woods. It's Cutler's back yard. Literally, it's his back yard.
natematt
Mar 26, 24 5:53 pm
it's their business if you want it to be their business...
Brian Cornwell
Mar 29, 24 12:57 pm
Thanks all, "direct glazing", etc. terms are what I was looking for. Good to hear about the first hand experience with sealants long term longevity.
Not curtain wall, just zero frame. Are they embedding it into the walls? I've seen videos where you can use angle iron at the exterior of the wall to nestle the IGU into then from the floor it's 100% glass, but there's thermal bridging concerns.
The options are pretty wide open.
The importance of thermal bridging is partly defined by your application, climate, and how much you care. There are still a lot of applications of hot rolled steel windows with worse thermal bridging issues than the custom angle stuff.
The custom angle stuff freaks me out more from a waterproofing standpoint because it’s relying on some maybe not so good craftsman. You can also do wood applications like you see here, but that has an additional issue with durability. That said, for someone’s personal cabin this seems like a reasonable approach.
Integrating a more standard system into a wall/ceiling/floor can be done, but there tend to be limitations and it can make glazing and de-glazing an issue since most basic systems are not designed to be installed that way.
For a commercial application what you really want is money! …. I mean insane custom manufacturer stuff. For example, the Broad Museum, https://www.saint-gobain-glass.co.uk/en-gb/broad-museum https://seele.com/ , or the nutso doors/entry glass at the grove apple store in LA, https://www.dezeen.com/2021/11...
In this design Cutler is just using single sheets of glass with wood stops and custom aluminum corner shapes.
Everything is 'waterproofed' by the roof overhang and caulking. The building has no insulation.
It's called direct glazing, popular in "hippie houses" of the 1970s and 80s. A few years ago I replaced several large direct-glazed windows and it was a pain--the sealant was still incredibly strong after 40 years--and I couldn't use my usual flashing details, but it seems to work if you know what you're doing.
Hippie houses. ::giggle:: On a serious note - some of that old sealant is almost indestructible and forever viscus. It must be all the carcinogens. ;)
It's also sometimes referred to as "stopped-in glazing". It's the way all windows were made back before industrial mass production made factory window units way more cost effective with better quality control. Basically, the window "frames" are built custom on-site by a finish carpenter (who ideally knows how to frame a window that doesn't leak ... these are in very short supply these days). The glass is inserted into the frame and then locked in place with sealant and/or wood frame "stops". For fixed glass units, this is still a perfectly fine way to build windows, but energy codes won't recognize them for anything except default performance on u values. Operable units are another matter entirely, since (as I mentioned) almost nobody knows how to actually build them from scratch anymore.
I've seen a lot of direct / stopped glazing in old MN buildings. The thermal performance of these types of windows (single pane) are absolutely horrible in a heating conditions.
In the right climate, with the right building orientation, and overhangs this type of glazing assembly can work moderately OK.
GW, I was going to say that's not how traditional hung windows were made, but on further thought that is one way to describe glazing a sash using glazing putty. (I've made several historic reproduction windows and doors, and restored many others.)
Chad, you can buy double-glazed or triple-glazed IGUs and direct glaze them. That's what we did on the direct-glaze project I mentioned. There is some thermal bridging at the perimeter but no more than on a factory-made, wood-framed unit.
Sorry WG - I was commenting on single pane glass like in the Cutler cabin. Double or triple pane glass in a direct glazing assembly work great! Getting the glass out without destroying the wood stops though - yikes!
On my project we had no problem getting rid of the wood stops, but the sealant between the glass and the framing was still intense! I felt bad for the glaziers that they gave a fixed price, but happy for my clients, as it took 2+ days for 2-3 guys to change out four windows.
Eeep! I've seen old sealant like that be a combination of concrete and silly putty - you can't get it off!
That's a good description.
Did we just come up with a way to make super durable buildings? Coat everything with that glazing putty?
Haha, that might do it! The closest I've used is this stuff, which is the same color and just as tenacious: https://www.3m.com/3M/en_US/p/d/b40066983/.
I helped my dad re-glaze a cabin with that stuff. I still have PTSD from the experience. ;)
3M 5200 marine sealant is great stuff. I keep several tubes of it on my boat. It will glue anything to just about anything else, with a long-term waterproof bond. But seriously, if you use it for something, don't do so casually. It will be there FOREVER.
. . and ever, and ever.
You can do structural glass installations with IGUs spanning vertically, but what you don't see are the significant head and sill details to clamp the glass in place.
The corner condition would be a mitered detail.
And, as natematt was aluding to, glass replacement strategies become a significant coordination issue
Too much glazing. What I do in the woods is no one's business
That's not the woods. It's Cutler's back yard. Literally, it's his back yard.
it's their business if you want it to be their business...
Thanks all, "direct glazing", etc. terms are what I was looking for. Good to hear about the first hand experience with sealants long term longevity.