What Is The Lowest Pitch Roof Everyone Is Comfortable With Putting In A Skylight?

mikeybobo

Hello, carpenter here asking a roofing quesion. I have 2 anderson skylights with the flashing kit. I'm changing the pitch on a shed style roof on a sun room on the first floor, and I want to lower the ledger height to get it away from the 2nd story windows. What is the minimum pitch everyone is comfortable with for a 28X48 anderson skylight with regular 3tab shingles?

RooferJim

Any pitch if you flash it right. low pitch you use a curb

Grumpy

Agreed to what rooferjim said. However follow the insallation guideliens of your manufacturer. I am sure Anderson has a written specification for how the skylight should be installed and it's warrantable limits.


Velux has some skylights which are able to be installed dead level, zero degrees. Like Jim said, build a curb. However some of the Velux skylights must be mounted 15 degrees. Further more Velux also gives high end limits, I think 85 degrees off the top of my head, so you don't go mounting skylights on walls as windows.

roofwiz74

same here,don't matter if it's the right one for the application

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Roofboy

Hello,

I would also use Ice and water shield from the eave to above the skylights. If you use a curb as was mentioned I would also wrap that as well. Make sure you wrap it up the side and then flap on top of the 2 by.

Keith

mikeybobo

Now what does everyone mean by use a curb if the pitch is low? I'm assuming you mean something above the window to divert the water around it? I have seen the small metal v shaped above skylights before that kind of looks like angle iron. Any other methods out there?

reveivl

A curb is just a 2x6 that supports the skylight off the roof. This curb can then be flashed or otherwise dealt with to keep the water where it belongs.

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Ed the Roofer

Mickeybobo,

You are referring to either a saddle or a cricket, which would divert the downward flow of water to either side of the structure.

Reveivl properly described a curb structure for you. Building a curb and then pre-flashing all 4 sides as Roofboy stated, exactly, is the proper way to go.

Ed

Grumpy

SOmething we should be asking... What is the pitch of the roof? Should there even be shingles on the roof is this question is being asked?

Ed the Roofer

Good point.

If it is a 3/12 or less, then to still install shingles, you would have to cover the entire decking with an ice and water shield product.

If it truly is that low of a slope though, a proper flat roof membrane would be a preferable choice.

Ed

Tom M

IRC says any skylight less than 3 on 12 should have a curb as described by everyone above. I would consider doing it for a 3 or even a 4. It can be done without if you have a good roofer but its a crap shoot on who knows what the're doing and who says they know what the're doing. If wrong it could be troublesome for years especially if your recycling a previously installed unit. Use the ice shield up the sides and get matching aluminum usually "territone or bronze" and make a new flashing system. Add a diverter as well for the hell of it the less traveling water it sees the better.