The installation instructions on Velux's web site are very detailed. Try again and look for the architect/builder section.

Here is a link that might be useful: instructions

Appreciated but been there and still have no clue as to what the basics are. Those instructions are written by someone too familiar with the product. A technonut.

Any help with by very basic above questions appreciated.

I agree with mightyanvil. Velux instructions are really excellent and precise.

I would strongly suggest reading up on skylight installation before proceeding. You should be able to find an in-depth magazine article or two if you do an online search.

Velux is also very picky on how to flash their units...it is in their standard instructions...you do it wrong and the skylight will likely leak.

Being a teacher for 35 years I know how frustrating it can be when simple questions are dismissed. I went into Home Depot and gave up on Velux exactly for the reasons you state. Couldn't make hide or hair of the Velux instructions. There were too many models and obtuse drawings. I installed two Sunburst Skylites instead. They might not be as good as Velux but no problems to date and they went in easy. If you've installed a door and give that a 5 out of 10 in difficuly then the skylite I instlled would be a 3 in difficulty. Can't comment on those clip things for Velux or how the wooden frame sits into the roof. Why not try emailing them directly.

What is the slope of your roof?

The Velux instructions show the inside and outside dimensions of the curb and a 3D drawing of how it sits on top of the roof structure and how Ice & Water Shield underlaymnet rolls up the curb and where the metal step-flashing is positioned. This is all you need in order to determine the size of the skylight to order.

Full instructions come in the Velux skylight box and the flashing kit box.

If you are unfamiliar with step-flashing follow the animation on the Velux site.

Personally, I cannot imagine how any building product could be better documented or easier to install.

Here is a link that might be useful: Velux flashing animation

Thanks for the link to the flashing animation. I didn't find that link previously on the site.i still don't see how it sits on the roof structure. On the rafters? On the sheathing?

I went into Home Depot today and asked the window fellow where the curb sits. Soon 3 of them were trying to figure it out. One fellow thought it sat directly on top of the ceiling rafters and another guy was sure it sat on the roof sheathing above the rafters. Anyways, they are going to contact the rep and let me know. One guy said not to worry about the clips as they simply put screws through the curb when the rep was demonstrating.

Go to the Velux website at the "Optional Link URL" below.

Select item 3 "INSTALL PRODUCTS"

Three Options are presented.

If you select the 2nd Option "EXPLORE INSTALLATION OPTIONS" you will see the 3 possible installation options (Deck, Curb & Self-flashing) and the step-flashing animation.

If you select the 3rd Option "SEARCH INSTALLATION DOCS" you will be offered 2 dialogue boxes for the purpose of selecting the installation PDF you need.

In the first box select the Category "SKYLIGHTS".

In the second box select the Subcategory "VCM/VCE CURB MOUNT VENTING SKYLIGHT" or "FCM (FIXED CURB MOUNT SKYLIGHT)"

Open the PDF file.

Curb dimensions are given and the 3D drawing shows how the curb sits over the sheathing and the framing. Of course, the framing might have to be adjusted so that this is possible.

There are no clips involved, they are used only to support non-curb mounted skylights.

Here is a link that might be useful: Velux website

I installed a "cheapie" PVC skylight in my kitchen once, and I installed a Velux with flashing at the same time in my Diningroom. Within 3 years elcheapo skylight, even with re-glueing with Tar Cement failed badly on my 5/12 roof over the summer.
Now 12 years later my Velux in the dining room has not failed once, I replaced the cheapo with a Velux fixed skylight & flashing & paid a carpenter 250 to fix my gypsum board around the install AGAIN.

Lesson learned, Velux and Anderson Skywindows are the best out here.

We had the cheap one's too in our house from the previous owners. I didn't think anything of them until one started to leak. We started at Home Depot too and not surprisingly the clerk there didn't know anything about which skylight we should buy or how to install. We ended up searching online and bought through these guys: www.theskylightstore.com The install instructions on the website were pretty straight forward and I actually called Velux for a few tips on installing the flashing. No more leaking and the Velux skylights look 100 times better than old plastic ones that were in. Don't waste your time and Home Depot or Lowes they never know top from bottom.

Here is a link that might be useful: The Skylight Store