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Step flashing, valleys, hips and ridges · Lesson 4 of 4

Step flashing, valleys, hips and ridges: defects, verification and case study

Missing and site-made kickouts, flashing layered in the wrong order, reroofs that bury the siding gap, nails and narrow sheets in valleys, cross-flow, cut caps and blocked vents, three inspection checklists, and a diagnosed sidewall leak.

You will be able to: Recognise the recurring defects at sidewalls, kickouts, valleys, hips and ridges, say which document the correct detail comes from, run a three-part inspection, and diagnose and document a sidewall leak.

10 min · 12 slides · 6 questions

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Slide 1 of 12

Kickout missing or made on site

PNNL says diverters made on site can be undersized and may have unsealed seams that allow leakage.

PNNL calls cutting a slit and tucking a diverter under the bottom shingles a less-than-adequate fix.

The gutter end should not touch the intersecting wall, so water can drain freely down it.

Correct and incorrect: the kickout at a roof-to-sidewall eaveTwo plan views of a sloped roof meeting a sidewall at the eave. Correct: a red one-piece kickout at the bottom of the step flashing throws the water running down the wall line out over the gutter, whose end stays clear of the wall. Incorrect: no kickout, so the water runs off the eave corner and down the wall behind the siding.DKickout sendswater out overthe gutterABECNo kickout:water runs downthe wallABECCorrectIncorrectPlan view of the eave and sidewall; not to scale

Two plan views of a sloped roof meeting a sidewall at the eave. Correct: a red one-piece kickout at the bottom of the step flashing throws the water out over the gutter, whose end stays clear of the wall. Incorrect: no kickout, so the water runs off the eave corner and down the wall behind the siding.

A
Roof covering
B
Sidewall
C
Step flashing beside the wall
D
Kickout diverter (AFS metal)
E
Gutter, its end clear of the wall
Both panels carry the same step flashing. Only the first has the kickout, and the gutter end does not touch the wall. Ticks and crosses are labelled in words. Not to scale.

Sources

Glossary

Siding gap
The clearance left between the bottom of the siding and the roof below, 0.75 to 1.5 inches in the PNNL guide, so step flashing and the barrier can lie flat.
Slit-and-slide retrofit
Cutting a vertical slit and tucking a diverter under the bottom shingles; PNNL calls it a less-than-adequate fix because it does not integrate with the house wrap.
Cross-flow
Fast water from one valley slope running across the valley and up under the shingles on the other side; ribs and inverted-V joints are the details that stop it.
Inverted V-joint
A one inch high raised joint along the valley centerline that UFGS 07 60 00 asks for where the valley slope is low or the roofs differ in slope.