An easy fix for split boots at plumbing vent flashings

Check out the photo below.  Do you see the problem?

32x Zoom

The white pipe sticking up out of the roof is a plumbing vent.  The rubber boot at the base of the plumbing vent is part of the flashing kit for this vent, and the boot has dried out and split.  Here's another photo of a split rubber boot, taken from the same roof at a different location.

Split boot at plumbing vent flashing

In preparation for this blog post, I hopped up on my own roof and took a look at the flashing on my own plumbing vents.  I bet you can guess what I found.

Split boot

I ought to inspect my own roof more often.  This is what happens to those cheap rubber boots over time.  They seem to last about 10 – 15 years here in Minnesota.  Here's water damage at a bathroom ceiling (not mine), which resulted from this defect.

Water damaged ceiling

I've always recommended replacing the plumbing vent flashing when I find this defect, but I recently came across a plumbing vent flashing repair device that looked like a cross between a two-piece plumbing vent cap and Darth Vader's helmet.  It's called a Perma-Boot®.


It's a simple product that can be easily installed in minutes, and comes with a lifetime warranty.  Home Depot sells them for $18.84, which is more than twice the price of the traditional flashing pictured at the beginning of this post, but I think it's worth the price.  They come in 1-½", 2", 3", and 4" sizes, but for the record, the smallest vent that you're supposed to have sticking up through your roof is 2".  The concern with smaller vents is that they could get blocked with frost too easily.

The only potential installation issues that I can foresee with this product are with plumbing vents that are too short or too tall.  Plumbing vents should ideally stick up out of the roof about one foot, and this is what is required by code here in Minnesota (see 4715.2530).  The taller the vent, the greater potential to get blocked with frost.  The shorter the vent, the greater the potential to get blocked by snow.  If you have a plumbing vents that's too tall for a Perma-Boot, simply cut it down.  If you have a plumbing vent that's too short, make it taller.

I think this is a great product, and I'm going to start recommending them when I find split boots.

Author: Reuben SaltzmanStructure Tech Home Inspections



p.s. – I think "Darth Vader helmet" is a better name than "Perma-Boot".

Written By

Reuben is a second-generation home inspector with a passion for his work. He grew up remodeling homes and learning about carpentry since he was old enough to hold a hammer. Reuben grew up thinking he was going to be a school teacher because he enjoyed teaching others so much. In a sense, that’s a lot of what home inspections are about, so Reuben truly does what he loves. Sharlene has worked with Structure Tech since 2000 and Reuben has been contributing to her blog since 2008.

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