How to set Insulated Glass Unit (IGU) in Exterior Door
I’m building an exterior deck door from white oak with a full IGU that is 7/8″ thick. IGU will rest in a rabbet for a seamless look on one side, and then glass stops/framing on the other side. Simple enough but installing the igu correctly has me second and third guessing that process…if not totally guessing.
1. Set Blocks–How many/ where do i place my hard rubber set blocks? One suggestion was to place two blocks on the hinge corner and then two more at the opposite diagonal (upper corner non-hinge side), which should self-square the IGU. Tried that on a dry fit and it doesn’t feel right though. Can i simply place two at the bottom-an equal distance from each corner, and then 2 on each side, near the corners? any blocks in the middle of the stile? top?
2. Adhesive–What adhesive or caulking should i use, if any? Should i set the IGU into a thin bed of caulk which has been applied to the rabbet ledge? Should i use caulk between my wood glass stops and the igu? (i did cut small quirks in the glass-side of the stops in case i do need to use caulk there.)
Intuitively it seems like a clean bead of caulk in the corner area of the rabbet then set/center the unit, using 4 stops even spaced on all sides, then a thin bead of caulk under stops, then finish nails.
Attached are some pictures of the parts in various forms so you can get a better idea maybe. Thanks so much for any advice or help.
Replies
Nice door.
Which side is the exterior?
Thanks. Exterior is the side with the stops/trim.
Here’s my thinking.
Two blocks at the bottom a couple inches in from each side, leaving some space at the top. And somehow one on each side a little over half way up that are loose to the glass but keep it not snug side to side.
Seal those mitres and all sides well before assembly. The lower mitres, those long edges of the mitre scream water entry. Maybe not now but you want this to last as well as be able to come apart in the event glass needs to be replaced. If this beautiful door is protected under a deep porch, all the better.
Sealant, something way better than usual caulk. Maybe a product from Sashco like Lexel.
https://www.sashco.com/products/lexel/
thank you calvin! i'll look into sascho and lexel for sure. appreciate the help.
My instinct is the same as your intuitive method. That's a big heavy igu and I might fill in between the blocks and door with caulk in addition to the set blocks.
What sort of joint did you use at the rail/stile intersection? They will have a lot of stress on them long run.
lol...well....funny you should ask. I essentially built this door just like norm did in one of his episodes. he used buttjoints and floating tenons. My tenons were the really big dominos--3 per joint. perfect glue up with plenty of squeeze out and all those dominos, so we'll see how long this thing will last.
I wanted to do more such as route mating groves and use door making router bits etc. in addition to the tenons...but in the end i just did what norm did (for the frame that is). If it fails i'll just re-build it and re-use the glass.
what do you think? will it fail?!
Might go a long time, might not. I'm assuming it is well protected from the weather or at least not really exposed.
I turned down a slightly more extreme job once and If someone wanted me to build to your exacting design I'd do it only with misgivings stated. That's just not much rail width to work with for any kind of joint. But be of good cheer, it is a nice looking door and I'm usually prone to over kill, it may last decades.
You’re going to want to bed that IGU in a quality caulk something dynaflex. The bottom trim piece you’re going to want to have it shed water if its flat it’s going to rot. 30 degree bevel should suffice. Door looks great!
30 degree bevel....i was wondering about that. i'll do it. and ill check out dynaflex! thx