Flashing vs Flashless Skylight

Old 07-20-18, 07:13 AM
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Flashing kit vs Self flashing Skylight

We are having a new roof and new skylight over the bathroom installed. The roofer was planning to put a self flashing deck mount Suntek model in.

i requested that he change it to a Velux flashing kit system like I currently have. I was concerned that a flashless system might leak especially in Kansas winters.

Did I make the right decision?
Old 07-21-18, 02:53 AM
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You can't go wrong with a standard Velux IMO. Just don't get all fancy with motorized shades and automated venting and it will last as long as the roof. SunTek says they've been doing it for "over 30 yrs." Velux invented skylights (roof windows) in 1941, over 75 yrs ago. Who would you trust?

This applies double if he was going to use an off the shelf polycarbonate "bubble" type. Yeeechhh!
Old 07-21-18, 02:44 PM
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I agree. The whole point of the step flashing kit is so that its easy for roofers to shingle around it and have it not leak! Practically foolproof.

A self flashing skylight will allow water under the shingles along the edges of the skylight (where it can leak in) it relies on water following the side flashing channels down until it can weep out the bottom. It dumps all that water on the bottom row of shingles.... water could potentially run sideways at any point above that.

Any roofer knows step flashing is superior because each shingle is individually flashed. With a "self flashing" skylight, the runoff is cumulative. If you get snow and ice, a "self flashing" skylight would probably leak, whereas one with a step flashing kit probably would not.

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