Let me try to “shed some light” on my experience. I have not done a ton of skylights, maybe six or so, but careful correct installation is key. Any roof penetration not properly installed will leak (chimney, plumbing vent stack, etc.) I have had an operating one in my bathroom for about 7 years now and not a drop.
Last fall I installed a Solatube model for a customer in a bath remodel and my current bath remodel customer has one prior to my current work. They both work very well at bringing natural light into a room. Here’s the benefits and drawback to a “tubular” skylight:
Benefits:
Less invasive. No cutting of roof or ceiling framing members.
No patching and painting of drywall, no construction of a “tunnel” to connect the roof and ceiling.
Small area to cut in roof to install the light dome.
Drawbacks:
You are limited to a maximum overall size to be able to fit between construction framing members, typically 16" o.c.
No “viewable” glass. They transmit light only.
No ventillation option. Fixed only.
Can not be used in a situation where the roof or ceiling is vaulted. You need a certain amount of attic space to connect the tube from the roof dome to the ceiling lens.
http://www.solatube.com/residential/product-catalog/brighten-up-series/index.php
http://suntunnelskylights.veluxusa.com/consumer/productinfo
Traditional Skylight:
Pretty much the flip side of the above. They do make units designed to fit between standard 16" o.c. rafter / joist spacing and there’s usually a little more roof area to open up and re-install. With either, you also have to consider the age of your roof and an installers ability to remove and re-install the shingles without complete destruction of the shingles. Otherwise your looking at trying to re-install new shingles and color match, and that rarely works out.
Both manufacturer’s versions of the tubular skylights are pretty much the same, and they both have their little options for powered light, lens covers, etc. One thing I noticed Velux offers is the flat roof lens option as opposed to the usual bubble. Might be of value to someone installing a unit where aesthetics are of concern.
This particular unit had the steam exhaust vent option since we were doing a complete remodel. She was able to save some money by incorporating the exhaust in the solatube instead of a standalone unit.
Stay away from any model with a “felxible” tube. Some people I spoke to at the home show said they definitely don’t transmit as much light and that makes perfect sense. The guy I bought the name brand “Solatube” unit from (shown above) was in the process of retiring and I don’t know if he sold the regional distributorship / business to anyone or is still doing them. He was willing to sell to me as a contractor to install myself.
I decided to market the Velux model as I can buy them directly from my local wholesale supplier (B and L) and not have to deal with a middle man. I have yet to install a Velux model but my research shows they are very similar.