Custom skylights

I am installing 3 skylights on the roof of my new shop. The windows are actually double pane insulated solar glass 30x31 1/4 that were originally from a wall of an office building. I have framed them between two rafters and raised them 2 inches (total) higher than the roof boards so they protrude above the roof boards. The have no flanges so they sit on top of the 30x31 1/4 frame ( like a box sticking out of the roof) The windows are 1 inch in thickness therefore there is two inch rise fron the roof. I have sealed them to the frame. Now I need to flash around them.
My question is?
1)How do I put flashing around them since I only have a 2 inch side? Obviously I don’t want them to leak.
2) Since there are no flanges, there is no way to attach the windows to the roof or the sides of the frame except with sealants, glues, etc. What’s the best way to hold them down so they don’t blow away in the first storm.
Thanks for your help.

to be really honest with you. Go and buy some real skylights. Vertical windows are not designed to have gallons per minute hitting them nor are the sealed for semi vertical installs. To flash them you would have to be a siding guy for his ablity to bend metal and even then it still could leak. I understand what you are trying to do, but why not do the job correctly with the correct materials? THen you will have many years of leak free service. Matter of fact i dont think you can even get what you are trying to do to ever stop leaking. Its just not the right material for the project.

I don’t totally disagree with gtp1003, but I suspect if you are like most people you got a good deal on these windows and want to use them. I don’t know that I can tell you everything you will need to do without providing you an AutoCAD drawing, and I obviously am not going to spend that kind of time helping out someone on the internet. However, I will tell you a few basic things you need to do. First of all, you need to raise your curb from 2-inches to around 8-inches. Next, you will need to flash the curb with roofing membrane, and since I don’t know if you have an EPDM, CSPE, BUR, Mod Bit, PVC or what type of roof, I can’t tell you how to flash it. After flashing the curb you will want to install a metal counterflashing that extends over the horizontal edge of the curb, this will provide you a surface to install your windows. Now, you can either install a butyl tape or a foam tape on top of the metal depending on how you plan on putting the “skylight” together.

Actually, let me stop there and ask you a question. You say they are double glazed. Are they tempered glass, and is there an air space between the two plates of glass? If it is a sealed system it will be easier to install than if you are trying to install two layers of glass and do it without the glass condensating between the two plates. However, when all is said and done, the only way I can see you being successful is if you have access to a sheet-metal shop and can make gasketed pressure-bars. As for the tempered glass question, if they aren’t tempered, throw them away and scrap the idea. If they are tempered, then you will basically be making a custom skylight and you will need to make sure the glass is secured with a pressure-bar, the pressure-bar has a continuous gasket, the skylight glass is set on metal and uses a sealant like butyl tape, and the skylight has a built-in gutter and weep system. I hope you are an engineer, or at least have a good understanding on water, condensation, etc. Anyway, last last bit of advice would be to build the curbs with a slope so water can easily run off of the “skylights.”

After you digest some of what I’ve said, if you are still interested in proceeding feel free to ask some more questions.

I just dont think it will work. They were never designed for that type of application. Not saying it is impossible but close to it for trouble free years.

Like I said, I hope he is an engineer. I could probably design the thing for him, even though I’m not an engineer, but I’d have to see it in person and take measurements, etc. Personally, I think it can be done, and I would see it as a challenge, but I wouldn’t try it unless I had access to a sheet-metal shop.

My thing is the a widow itself is not designed for that type of application. THey are not designed to have water pound on them and snow sit on them. Now in not saying it cant be done but really think about how many times people use items for something they were not designed for and then have major issues. I still feel he would be better off buying 3 skylights rahter than testing and redesigning the wheel. THink of the money he will spend on tinkering with this and the time. I highly doubt he will be able to get the windows the 8 inches off the deck to get it to flash not even thinking of the pressure bent flashing. 300 bucks a skiylight and a 10th of the stress and headaches.

Hi guys. Thanks for answering. After reading your posts I almost gave up but I am hoping there is still hope. Forgive me if I don’t know what I am talking about as I am not a pro…but here goes a few more questions:
First, the window is made of two sheets of “safety tempered” glass with an air space in between. There is a strip of metal going around it with some rubber looking cover on top of the metal. there are little granules between the metal and rubber. The window seems sealed somewhat under pressure. (I know because one broke and shattered everywhere into crumbles) They are made by “Guardian Glass”. the roof is made of one inch unplaned ten inch boards cut from my connecticut farm.
1)Raising the curb to 8 inches is possible but what if I lower the curb so the windows run level with the run of the boards and then flash, seal and shingle around it and ON TOP of the edge? Seems to me this would eliminate some of the risk of wind damage. Just tar the heck out of it four ways around between the metal strips and the window
2)OR If I left it at 2 inches, I thought of using a z bar type “deck edging” strip sold at home depot as a flashing. It could surround the edges of the window
and be sealed with some silicone caulk, It could serve as flashing as well as hold the window down.
3) Obviously #1 and 2 are just an uninformed idea. If I were to go with Cerebrus idea,what do you mean by a pressure bar, counterflashing and where do you get butyl tape?
Thanks for your thoughts. I will give up if this is all impossible,; let me know what you think

I think it would be alot easier and cheaper to just go out and buy a few skylights. they are about 300 to 400 a piece.

Are you trying to put these “skylights” on a sloped shingle roof? I was under the impression you were trying to install them on a flat roof.

Anyway, after reading your other questions I’m now of the opinion that you would have a very hard time constructing a skylight out of the glass, and you are better off not trying. If you don’t have experience with skylights, then you would be your own worst enemy if you proceeded with a project like the one you’ve started.

I think its a sloped roof. Either way seriously he needs to buy skylights. It just wont work there is no frame, no special bent curbs nothing just a piece of double pane. I wish i could help you out but what you are asking is seriously very hard to do and without the proper metal work and framing this thing could leak forever. As far as making it flush you can not do that and flash at the same time. I never seen a flush skylight. Good luck with your project.

if your gonna try those things.
set em flush and seal out on em as you said in #1
good luck.



It is your shop go for it.

** Think like water. Think like water. Think like water.**

The cheap plastic skylights are all mounted flush.

Do not use a silicone caulk. Use Geo-Cel that is make to use with roofing materials.

There are several ways to do it. If it leaks you can laugh and say I tried. If it does not leak. You can just be totally amazed that you did it.

Good luck.

If you posted some pictures might be able to give more specific suggestions.

I get into those tough spots. I just sit there and look at it and Think like Water.

Hey guys,
yeh it is just a shop and I’m not a quitter, Built everything else myself so why not try Please Keep the encouragement going and some how to advice…

so far I am up to having these windows sealed and glued to a curb sticking out 2 inches above the boards-one inch of curb frame and one inch of the width of the window.I couldn’t pull the window off the curb if my life depended on it, but I figure over the long run I should attach them to the roof somehow. If I drop the curb (easy to do) so the window is flush with the roof boards (the slope is 3/8), then it is a matter of putting some sheet metal all around the top edge and side border of the window. Seal everything and then shingle around it. Water would run over the window like it runs over the shingles. BUT snow is heavy in Connecticut…so would I have trouble with snow melting?

What are some other ways to do it if this isn’t the best bet? Thanks for your ideas. I went to lowes to look at a velux $200 skylight and it didn’t look much different from what I am trying to build. Take care

The problem with snow is that you will have heavy snow on top of the skylight and with really nothing holding that glass in you could have many troubles. The weight can be a concern. If you dont have a frame around it you will have many problems. Still with the time you will invest in it will out weight the skylight you buy that has all the correct flashing and does NOT need to be caulked. I for one am not a fan of caulking anything that would be concidered as such. Without flashing the glass you will have periodic problems that you can not stop. I think it is a poor way of doing this job. DO what you want it your time and money. I just think it would be better spent with a product designed for what you are doing. And who knows if that glass can withstand the weight of a heavy snow without breaking, since it is not designed for that.

I could build this for you for like $3000 or you could buy one for $300… I concur with gtp…

Those cheapo skylights have a flange that goes under the shingle a little he has nothing other than a gap. I dont know about you but i would not trust this no matter what you do. Im stil a firm believer in buying some Velux skylights and calling it a day. Hey if you can make it work fine but why not do it the right way from the start. I was taught do it right or dont bother.