Skylights vs roof longevity and performance

Ned Harr wrote:This is great, but did you guys read the thread title? Nobody is even TRYING to change my mind!

Ned Harr wrote:This is great, but did you guys read the thread title? Nobody is even TRYING to change my mind!

Ned Harr wrote:roof-non-penetration purist zero roof penetrations.

I'm not completely sure what you mean and I might also be biased coming from Velux country.

My roof is made of large (1 sqm-ish) wavy boards that overlap by one wave. The flashing for the windows is installed so it continues the overlapping in the same way which means it doesn't become the weak point you're worried about.

Velux is the brand name for a type of skylight. They have all kinds of cool configurations. Even a balcony flip up with railings type of design. There's also a company called Fakro that does the same style of windows.

Mine were installed i '74 and have only had to have a pane replaced because somebody broke the glass.

If you get a triple paned window then you're well on your to a lovely and isolated exterior.

In the picture you can see the difference in how much heat is lost on an old double paned themo window and a new tripple paned one.

Ned Harr wrote:This is great, but did you guys read the thread title? Nobody is even TRYING to change my mind!

Leslie Moody wrote:I’ll second the health care aspect of skylights. Plants love them, especially in winter. So do humans...
We’re in the SW, so light is abundant and rain is sporadic (but abundant when it comes). The light from above is brighter, longer and more enveloping than the clerestory light, period.

Ben Zumeta wrote:Another aspect of this is how vertically facing skylights are both more prone to leaking and let light in most at the least beneficial time of year. A steeply pitched equatorially or east facing roof can have a skylight that more easily sheds rain on its uphill side, and catches winter and morning light that is most beneficial.

When we first moved to this area, we trusted my park ranger boss’s recommendation for a roofer. It turns out that roofer knew better than to screw over someone as connected in the community as my NPS boss, but he shorted and shafted everyone else. The skylight we had installed with a roof replacement on the shallow pitched roof of a fixer upper we could afford leaked immediately. It turned out the incompetent and malfeasant roofer did everything else wrong as well, which I should have caught but was distracted by wedding planning and still generally believing people were good during those halcyon days of just engaged optimism. When we went after his license, the county inspector he must have paid off lied about it raining during his retroactive “inspection”, which the roofer had lied about getting in the first place. When we looked into suing, we found we would be in line behind 2 dozen other litigants against him. He is well connected so he stayed in business, and I subsequently saw his company working on the public school buildings here, which says a lot about our county and how it is run. In hindsight, having done roofing work since (and virtually everything else because we can’t seem to hire good honest people here easily), I think any competent, sober roofer could put in a sound skylight that does not leak.

Our new house built by a general contractor for himself has no leaks after 300” of rain and 10+ feet of snow in 3yrs. It is NE facing, so it does not add much heat in summer, and it even opens to vent heat. It lights the interior stairwell enough to grow shade loving plants. Our large, high S and E facing windows catch abundant winter and morning light. Beyond a competent roofer, aspect is the most important consideration in my opinion.

Pearl Sutton wrote:The more I think on this thread, the more I think that putting square skylights diagonal to the roof line is a good idea. If you look at how they put in dormer windows, the contact point to the roof is pointed, to let the water flow past.


Doing that with a skylight would make it even less likely to be a problem.

Dormer windows might work nicely too, actually. I like clerestory because they are easier to build, messing with roof lines is always expensive, the fewer direction changes the cheaper it is, but dormers are neat too.

Jim Fry wrote:You may be asking the question incompletely. It's not just about roof life. It's really a question of balance of how much will the view of sky, and Sun, and the extra light enhance your life, and how much will the possibly incorrectly installed sky light cause you problems.

John C Daley wrote:
I have a number of reasons for loving skylights;
- see the moon and stars shining through the roof is wonderful
- I love watching the rail hit the glass and move off
- I can get light into dark spaces, even underground.
- Cloud watching from your lounge chair is cool.

Jordan Holland wrote:I would avoid dormers. In the pic shown, you can see all the places water can have a chance to intrude around the edges, but also you now have extra eaves and soffits that can rot, and the perfect overhangs for wasps and birds and who knows what else to colonize. I would say just a couple or few dormers would easily double the amount of work making the roof. The one in the pic is at the peak, which would be best, but still, those valleys on a shingle roof especially are just another area asking for problems. A valley the entire length of the roof is one thing, but one that terminates in the middle of a roof is an easy place for people to mess up from what I've seen.

Ned Harr wrote:Skylights add complication and cost, and require extra skill to install properly, and I can easily envision a scenario in which skylights could be the difference between having a house that is built on time and on budget, and not having one.

Jordan Holland wrote:

Pearl Sutton wrote:The more I think on this thread, the more I think that putting square skylights diagonal to the roof line is a good idea. If you look at how they put in dormer windows, the contact point to the roof is pointed, to let the water flow past.


Doing that with a skylight would make it even less likely to be a problem.

Dormer windows might work nicely too, actually. I like clerestory because they are easier to build, messing with roof lines is always expensive, the fewer direction changes the cheaper it is, but dormers are neat too.

I would avoid dormers. In the pic shown, you can see all the places water can have a chance to intrude around the edges, but also you now have extra eaves and soffits that can rot, and the perfect overhangs for wasps and birds and who knows what else to colonize. I would say just a couple or few dormers would easily double the amount of work making the roof. The one in the pic is at the peak, which would be best, but still, those valleys on a shingle roof especially are just another area asking for problems. A valley the entire length of the roof is one thing, but one that terminates in the middle of a roof is an easy place for people to mess up from what I've seen.

Luke Mitchell wrote: I love our Velux windows. I can hear and see the rain (and it gives me a much better idea how how hard it is raining than just looking out of a regular window). I can also see the moon at night - one of our three skylights is right above the spare bed.

The downside, for me, is that they are difficult to maintain. The outside of the windows gets pretty green with algae and, whilst they haven't leaked, they are unsightly and difficult to access and clean. They are also difficult to open for airflow - we have a long stick with a hook for the task!

Ned Harr wrote:I am biased against skylights,.........I would aim for zero roof penetrations.

should I be biased against skylights? Or should I compromise and allow a roof penetration or two...... (I'm familiar with traditional skylights--both opening and fixed--and those solar tube things, but surely there are other types I don't know about...)

Joseph Bolton wrote:
Roof penetrations done right are zero risk forever, and if you want instructions on how that can work, let me know. My background: aviation maintenance and mechanical engineering. How much do you think the windshields leak on all those aircraft built in the 1950s with original plexiglass still installed today? Most of them, not even a drop at +100mph through rain.

We can make a penetration for a skylight on a roof not leak a whole lot easier and just as reliably and for a whole lot less money.

Joseph Bolton wrote:In the example of 1950's small aircraft windshields I'm familiar with, they are all non-pressurized. Actually there is a slight negative pressure when flying, so any leak would tend to suck in water when flying through rain. That's why there are drains on the pitot static plumbing.