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Door insert thickness?

Posted: Sun Jul 15, 2012 10:41 am
by Anjru
Hi. I'm new here. This is my first post. I tried searching to see if this question was already discussed but I didn't see it. 8-[

I'm interested in making a glass panel inset for my front door, about 18" x 58". My plan is to make it out of random pattern bars pieces, Coe 90. I'm wondering how thick the inset should be so that it's strong enough. I'm thinking 1/2 to 3/4" should be enough but that's just a guess.

Also, I'm guessing that will make the piece pretty heavy. Maybe there's some sort of weight chart that would allow me to figure it out?

And given the weight, I'm wondering if it'll impact the opening and closing of the door. The door in question is a hollow core front door. It's got a security door in front of it and I'm in a gated community. So I'm not really concerned with break-ins.

Thanks in advance.

Re: Door insert thickness?

Posted: Sun Jul 15, 2012 10:55 am
by Valerie Adams
I'm sure others with architectural-installation experience will reply, but my front door has a leaded glass insert and it's only single thickness. It's the fairly common kind, where nearly half of the top of the door is glass. I can't imagine why you'd had to make your insert so thick.

Re: Door insert thickness?

Posted: Sun Jul 15, 2012 11:21 am
by Bert Weiss
There are no charts I know of. Generally to meet building codes, glass in a door must be safety glass (laminated or tempered). There are a couple of ways to accomplish this. My suggestion is to find a company what can resin laminate it with a low contraction resin. I would probably laminate to a sheet of tempered, clear glass. Another approach would be to create a triple glazed panel with the outer panels being tempered glass. All that said, some building inspectors will allow you to use an art glass exception. Not all will. If you do happen to do this, be sure to insist on a high quality hydraulic door closer so the door can't slam shut.

Weight is not an issue here. A tall thin panel does not have problems created by weight. For that reason, I would want my art glass panel at least 6mm thick and thicker might be better. Whatever the weight ends up being, you need a sufficient hinge system on the door. Be sure to use neoprene setting blocks beneath the glass.

When it comes to resin laminating, the standard resin used is not a good choice. It has a contraction coefficient of 13%. This will tend to break art glass. At least 2 companies make a low contraction resin, about 3%, that is a good choice. This process is relatively simple as it does not require expensive equipment. It does have a steep learning curve as it is quite difficult to seal the resin in the glass before it sets up. I have done this myself and choose to work with a company that is better at it than I am.

Re: Door insert thickness?

Posted: Sun Jul 15, 2012 11:56 am
by Anjru
Thanks Bert.

I hadn't really thought about building and safety codes since I was going to pull a permit to install the glass. But maybe adding a sheet of tempered glass to the thickness would be a good idea anyway both for code and strength. I get my glass from pacific art glass here in Los Angeles. I was just there yesterday and he talked to me about laminating. He didn't mention shrinkage rate but now that you have I'll ask about it. They were talking triple glazed, a glass sandwich.

I checked the weight of glass, 162 pounds per cubic foot. So my piece, at a half inch thick would weigh about 40 pounds.

I don't do my own fusing. I have it done at a local studio. I'll ask her about the neoprene blocks but I'm guessing she already knows. :wink:

Re: Door insert thickness?

Posted: Sun Jul 15, 2012 12:56 pm
by Bert Weiss
Anjru wrote:Thanks Bert.

I hadn't really thought about building and safety codes since I was going to pull a permit to install the glass. But maybe adding a sheet of tempered glass to the thickness would be a good idea anyway both for code and strength. I get my glass from pacific art glass here in Los Angeles. I was just there yesterday and he talked to me about laminating. He didn't mention shrinkage rate but now that you have I'll ask about it. They were talking triple glazed, a glass sandwich.

I checked the weight of glass, 162 pounds per cubic foot. So my piece, at a half inch thick would weigh about 40 pounds.

I don't do my own fusing. I have it done at a local studio. I'll ask her about the neoprene blocks but I'm guessing she already knows. :wink:
The weight factor I work with is 154 pounds per cubic foot for soda lime glasses. With this figure, 3mm weighs roughly .75 lb per square foot. 10mm weighs 5 pounds per square foot.

Setting blocks come in various thicknesses. You can use 1/8" or 1/4". They are best placed at the quarter points of the width. You need to compensate for these when you design the length of the glass.

Chances are good that anybody resin laminating art glasses, is using the right resin. My fabricator happens to use the low contraction resin for all their work, but the high contraction is far more common when working with flat float glasses. One advantage of choosing to laminate your art glass is that you get to put it on the exterior or interior surface.

Re: Door insert thickness?

Posted: Sun Jul 15, 2012 5:13 pm
by CH Glass
I would recommend having your fused panel sealed in an insulated glass unit. I believe building codes will require both sides to be tempered. If it were my fused glass panel, I'd want it protected from all the things that can happen to a door light, inside and outside.

Re: Door insert thickness?

Posted: Sun Jul 15, 2012 6:08 pm
by Bert Weiss
CH Glass wrote:I would recommend having your fused panel sealed in an insulated glass unit. I believe building codes will require both sides to be tempered. If it were my fused glass panel, I'd want it protected from all the things that can happen to a door light, inside and outside.
That will work, but there are some advantages to the other way. First, the IG unit will be best sealed when both interior surfaces are smooth float glass. Second, laminating adds strength to the panel, as well as making it safety glass. And third, the art glass will look it's best on the outside of the unit. If it were my design, I'd put the art glass in the interior space. At night, with the lights on in the house, it will still look great from the outside, and you get to see and feel the glass on the inside, as well as take advantage of the sunlight during the day. The home owner needs to know to be careful, and keep kids and crazy dogs from mauling the window, or throwing baseballs at it, and not let the door slam.

Re: Door insert thickness?

Posted: Mon Jul 16, 2012 11:43 am
by Anjru
I'm not understanding all this. For instance, an insulated unit vs lamination. I don't know the difference. Lamination is attaching glass to one or both sides, right? Insulation is what, putting tempered glass on both sides but then attaching them to each other instead of to the interior piece?

Bert, I'm not getting what you mean by putting the art glass on the In the interior space. Also, both surfaces on smooth float glass? Well, maybe. But I'm not quite sure that I get this either. I guess the piece is completely covered with The resin, hence the tempered laminate is "floating".

The door will have a hole all the way through it. I guess my mistake, sort of, for calling it an inset. Also, this door is in my home. No dogs. No kids. No fastballs. No slamming. No sunlight either, unfortunately, though there's plenty of indirect light as well as outside lighting which goes on with clockwork.

And setting blocks at the quarter panel marks. Like I said the studio I go to handles most of this. Kristen duCharme, maybe you know her?

Not sure what all these smileys mean. But I like them. : \:D/

Re: Door insert thickness?

Posted: Mon Jul 16, 2012 11:59 am
by Bert Weiss
Typically a door will have an insulated glass unit made with 2 pieces of clear tempered glass sealed with an airspace, possibly filled with inert gas. That is called a double glazed insulated glass unit. You can make a triple glazed IG unit with the art glass in the center of the unit, being protected by tempered glass on both sides.

Safety glass is required. Glass can be transformed to safety glass by either tempering it or laminating it.

Laminated glass has 3 layers, glass - plastic - glass. The plastic holds it all together in case a piece breaks. The most common technique to make this uses a PVB piece of plastic that is sandwiched and placed in an autoclave with both vacuum pressure and heat to make them all stick together. Resin laminating is an alternative that uses a liquid clear epoxy between the layers. The trick here is to get the resin in, the bubbles out, and keep the resin from leaking out before it sets up. Believe me, it really wants to leak. It is possible to resin laminate with a minimum of special equipment. A tilt table is the biggest tool. This technique is the least likely to break the art glass, and cure with no gaps or bubbles, if done right.

If you resin laminate your art glass to a piece of either tempered or annealed float glass, it will qualify as safety glass. When making an insulated glass panel, you would have the choice of placing the art glass on either side. The IG unit will seal best if the flat float glass is in the interior of the unit. This will leave the art glass on the exterior. You would then have the choice of placing the art glass facing the exterior of the house, or the interior.

If your building inspector allows it, you could make the door with a tempered double glazed IG unit, and place the Art glass on the interior side of the door. You would have to set it, not sealed and with venting, so any moisture that condenses on the inside of the art glass has a pathway out. If the inspector is strict, this will not be allowed.

On a fifteen inch wide panel the quarter points are at 3.75" from each edge. All glass lights, regardless of size are set on 2 setting blocks placed at the quarter points. This is the least stressful way to set all glass. The only exception I can think of would be leaded glass set in an exterior H came.

Re: Door insert thickness?

Posted: Mon Jul 16, 2012 1:14 pm
by AndyT
Bert Weiss wrote:
CH Glass wrote:I would recommend having your fused panel sealed in an insulated glass unit. I believe building codes will require both sides to be tempered. If it were my fused glass panel, I'd want it protected from all the things that can happen to a door light, inside and outside.
That will work, but there are some advantages to the other way. First, the IG unit will be best sealed when both interior surfaces are smooth float glass. Second, laminating adds strength to the panel, as well as making it safety glass. And third, the art glass will look it's best on the outside of the unit. If it were my design, I'd put the art glass in the interior space. At night, with the lights on in the house, it will still look great from the outside, and you get to see and feel the glass on the inside, as well as take advantage of the sunlight during the day. The home owner needs to know to be careful, and keep kids and crazy dogs from mauling the window, or throwing baseballs at it, and not let the door slam.
double check the codes. In my area "Art Glass" is exempt from the codes. You can still buy brand new doors at most building supply places that only have the leaded glass in them. you can also buy them with the leaded glass sandwiched in a thermal unit.

Re: Door insert thickness?

Posted: Mon Jul 16, 2012 2:44 pm
by Bert Weiss
AndyT wrote:
Bert Weiss wrote:
CH Glass wrote:I would recommend having your fused panel sealed in an insulated glass unit. I believe building codes will require both sides to be tempered. If it were my fused glass panel, I'd want it protected from all the things that can happen to a door light, inside and outside.
That will work, but there are some advantages to the other way. First, the IG unit will be best sealed when both interior surfaces are smooth float glass. Second, laminating adds strength to the panel, as well as making it safety glass. And third, the art glass will look it's best on the outside of the unit. If it were my design, I'd put the art glass in the interior space. At night, with the lights on in the house, it will still look great from the outside, and you get to see and feel the glass on the inside, as well as take advantage of the sunlight during the day. The home owner needs to know to be careful, and keep kids and crazy dogs from mauling the window, or throwing baseballs at it, and not let the door slam.
double check the codes. In my area "Art Glass" is exempt from the codes. You can still buy brand new doors at most building supply places that only have the leaded glass in them. you can also buy them with the leaded glass sandwiched in a thermal unit.
The code is national, but interpretation is local. I was astounded when I visited Savoy and saw a cast panel and inch and a half or thicker, that they told me was going to be put in a door. A single layer of annealed glass would never pass inspection in the Northeast, regardless of thickness. As well, nobody I know builds today with single pane glazing, anywhere on the exterior of a building. Therer are places where the art glass exception will not fly, like shower doors. Leaded glass sometimes gets away in a door, but I can't think of an exterior retrofit in Northern New England, done since the 70's, that doesn't include tempered glass in the configuration.

Re: Door insert thickness?

Posted: Tue Jul 17, 2012 8:22 am
by rosanna gusler
this is all good info but i wonder why anybody would worry about code when changing out the glass in their own door? even if it were new construction i would just wait untill i had my c.o. and do whatever i wanted to with my door. rosanna

Re: Door insert thickness?

Posted: Tue Jul 17, 2012 12:53 pm
by AndyT
rosanna gusler wrote:this is all good info but i wonder why anybody would worry about code when changing out the glass in their own door? even if it were new construction i would just wait untill i had my c.o. and do whatever i wanted to with my door. rosanna
If you did that and put in any other type glass and say something happened and the glass broke and injured someone...you'd be at fault. But then I suppose your insurance would pay for it...maybe.

Re: Door insert thickness?

Posted: Tue Jul 17, 2012 2:36 pm
by Anjru
My door. Not changing the glass out. It's a new install. No hole in the door now. Right now I'm thinking of fusing maybe a quarter to a half inch thick, then laminating one side to safety glass. That should be strong enough and safe enough. I'm not going to get building inspectors involved.
:-"

Re: Door insert thickness?

Posted: Tue Jul 17, 2012 2:50 pm
by Bert Weiss
Anjru wrote:My door. Not changing the glass out. It's a new install. No hole in the door now. Right now I'm thinking of fusing maybe a quarter to a half inch thick, then laminating one side to safety glass. That should be strong enough and safe enough. I'm not going to get building inspectors involved.
:-"
In West LA you don't have cold to deal with. Unless you spend a lot on air conditioning, that should be fine.

Re: Door insert thickness?

Posted: Tue Jul 17, 2012 3:51 pm
by rosanna gusler
AndyT wrote:
rosanna gusler wrote:this is all good info but i wonder why anybody would worry about code when changing out the glass in their own door? even if it were new construction i would just wait untill i had my c.o. and do whatever i wanted to with my door. rosanna
If you did that and put in any other type glass and say something happened and the glass broke and injured someone...you'd be at fault. But then I suppose your insurance would pay for it...maybe.
i doubt that. most older houses have no tempered anywhere and they get ins and are bought and sold as is every day. rosanna

Re: Door insert thickness?

Posted: Tue Jul 17, 2012 7:20 pm
by Morganica
And you're putting all of this into a hollow core door? The ones I'm familiar with would essentially need to be reconstructed--i.e., you'll have to insert bracing around the window, inside the door and out to the edges, to support the glass. I once tried inserting a panel in one of those doors, and by the time I got finished I'd pretty much rebuilt the door. Would have been faster to simply get a solid door at the rebuild center.

If you've got a lockable safety glass door in front of this one I wouldn't worry about intruders, I guess (tho a gated community isn't THAT good at keeping out determined intruders, in my experience)...but that's still a lot to ask of a hollow core door.

Re: Door insert thickness?

Posted: Tue Jul 17, 2012 9:20 pm
by Anjru
Right. It's a waffle reinforced hollow core. But I have a carpenter that can do the build to insert it. So no worries there, thanks. My initial queries have been answered though, I think. So I should be good to go, as they say, for now, anyway. =D>

Re: Door insert thickness?

Posted: Tue Jul 17, 2012 10:12 pm
by Tod
...more to consider:

http://groups.yahoo.com/group/stainedgl ... sage/13086

codes and the reality of having custom insulated units made don't align nicely. Good luck!