How to Repair a Leaky Roof Vent Pipe Flashing – Part 2

The rubber vent boot cracked causing a roof leak at the PVC vent pipe. I hired a roofer to replace the vent boot flashing and install a rain collar for extra leak protection.

This repair is continued from How to Repair a Leaky Roof Vent Pipe Flashing – Part 1.

Cracked Roof Vent Boot Flashing Repair

I called several roofing companies in my area about the cracked vent pipe flashing but none were available due to the once in 500 year flooding rains that fell in September. One company said they’d received 600 calls on Monday and most could only put me on a waiting list for a call back. I was quoted $125 to install lead pipe flashing for labor and materials, but no one could promise when they could get to it.

I was able to buy an Oatey Galvanized Base No-Calk Roof Flashing at Lowes for about $7 that fit a 2″ inch vent pipe. I would have preferred a lead pipe flashing because it’s the best and longest lasting flashing solution that avoids the problem of cracked rubber boots. I can always hire a roofer when they’re not so busy and have lead flashing installed.

Oatey Galvanized Base No-Calk® Roof Flashing

Oatey Galvanized Base No-Calk® Roof Flashing

Replace the Roof Vent Pipe Flashing

The steps to remove the old roof vent flashing and install a new one is simple:

  1. Pry up the roofing nails used to attach the old flashing.
  2. Gently lift up the shingles above the flashing.
  3. Lift the flashing off the vent pipe.
  4. Slide the new flashing over the vent pipe.
  5. Tuck the uphill part of the flashing under the shingles.
  6. Fasten the new flashing with galvanized roofing nails.
  7. Apply a dab of roofing sealant to the nail heads and bottom tabs of the shingles that were disturbed.

The entire job takes less than 15 minutes. It seems easy and it is, unless you have a high and steep roof like mine. A 40 foot ladder is necessary to reach the roof from the ground and I’m not comfortable working so close to the edge of the roof. Time to hire a professional roofer but none were available on short notice. What to do?

I got lucky and noticed a roofing crew working in the neighborhood. I asked the foreman if I his crew would install the new vent flashing. He said they were almost finished with the current job and could send someone over in 45 minutes. He asked if I had the new vent flashing, I said yes and showed him the Oatey No-Caulk flashing. He said he would install my flashing and add a rubber rain collar for extra protection for $50.

Two men from the roofing crew a short while later as promised. They setup a 16 foot ladder by the garage and bear crawled up the hip ridges with a big block of foam rubber (couch cushion) wearing regular tennis shoes with amazing agility! The roofer is getting into position to begin work:

Leaky Vent Pipe Flashing Repair: Roofer Getting into Position

Leaky Vent Pipe Flashing Repair: Roofer Getting into Position

The roofer pried up the nails and is removing the old vent pipe flashing. The block of foam rubber grips the roof so he doesn’t fall. The new flashing is tucked under the edge of shingle above him so it’s doesn’t slide away:

Leaky Roof Vent Pipe Flashing Replacement

Leaky Roof Vent Pipe Flashing Replacement

The new flashing is slide over the pipe, tucked under the shingles on the high side, and nailed to the roof.

BASF SONOLASTIC NP 1 roof sealant is applied to the nail heads and bottom tabs of the roof shingles that were raised to install the flashing. This makes everything waterproof and ensures the shingles are glued to the next row so they won’t be lifted by the a strong wind.

Roof Vent Pipe Flashing Replacement: Apply Roof Sealant to the Nail Heads

Roof Vent Pipe Flashing Replacement: Apply Roof Sealant to the Nail Heads

Rain Collar – Roof Leak Repair in the Rain

Rain & Repair Pipe Collars are a the rubber boot that acts like an umbrella to shed water over a cracked pipe flashing. The rain collar can be installed while it’s raining or wet for an emergency fix. No caulking necessary because it stretches over the pipe for a water tight seal.

This is the new roof vent flashing with a rain collar for extra protection from the sun’s UV light and weather:

New Plumbing Roof Vent Flashing with Rain Collar

New Plumbing Roof Vent Flashing with Rain Collar

Cracked Roof Vent Pipe Flashing

The boot on the old Oatey all-plastic vent flashing was severely cracked/split in the places. This broke the watertight seal around the 2″ PVC vent pipe and allowed rain water to leak in and run down the vent pipe onto the drywall ceiling. This vent boot failed after about 10 years on the southern exposure of the roof:

Roof Leak caused by cracked and split Vent Pipe Flashing

Roof Leak caused by cracked and split Vent Pipe Flashing

Side view of the cracked rubber vent pipe flashing:

Cracked and Leaky Plumbing Roof Vent Boot Flashing

Cracked and Leaky Plumbing Roof Vent Boot Flashing

Roof Vent Pipe Boots: A Better Method

My roof was later damaged in a hail storm and had to be replaced. The roofing company recommended Perma-BootA permanent solution for leaking pipe boots” which are installed over the standard pipe flashing. I like the Perma-Boot because it’s covers the vent flashing rubber boot and does a good job preventing squirrels from gnawing on the vent boot.

Take care,

Bob Jackson

Copyright © 2016   Reproduction strictly prohibited.

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46 Responses to How to Repair a Leaky Roof Vent Pipe Flashing – Part 2

  1. johnny goyen February 9, 2010 at 2:26 am #

    Thank You for this information. I’m no roofing expert..well..I know a heck of a lot more now thanks to your pictures and links. The Rain Collars are great. It was impossible to purchase them locally in my City of Austin, Texas. Nobody stocks them! What A Quick Fix. Thank You Again. Johnny Goyen Austin, Texas

    • Bob Jackson February 9, 2010 at 8:42 am #

      If a rain collar isn’t immediately available, you can always cut out the rubber boot from a standard flashing and slide it over the vent pipe to cover the cracks in the old boot.

      Bob Jackson

  2. Phil Boleski July 29, 2010 at 3:21 pm #

    My old boot looked like it was melted and separated from the plastic pipe just enough to leave a space for rain to enter. I was able to remove the rubber boot from a new aluminum flashing by pulling it out of the channel it’s tucked into. If you pull hard enough it will come out. I cleaned the deteriorated rubber from the old boot with a putty knife and sandpaper and siliconed the gap on the old boot for added protection. I applied a little dish detergent to the plastic pipe to make the rubber slide on easier and slid the new rubber boot on without the metal flashing creating a little “umbrella” directly over the existing boot. A quick fix that should last for as long as the new rubber boot lasts for less than $7.00.

    • Bob Jackson July 29, 2010 at 5:20 pm #

      Yes, that will work. You’ve made a field-expedient rain collar and avoids removal of the old boot flashing.

  3. Dave November 28, 2011 at 4:41 pm #

    I just repaired 4 leaky roof vent pipes. I used the plastic oatly roof vents I got from home depot $7 per piece. There was nothing wrong with the existing flashing. I simply cut out enough of the new piece and slid down over the existing flashing. I used a little ‘Roof Jack’ petroleum based asphalt sealer on the top of the old one, so when I pressed the new piece that I made it would have something to adhere to. What I didn’t realize is the in small words on the new Oatly vent flashing, which is made of all plastic and softer rubber to seal around the pipe, are words that say ‘Petroleum Based Sealants should be avoided’ Do I have anything to worry about? Will this type of sealant cause any harm to the plastic/rubber?

    • Bob Jackson November 28, 2011 at 5:34 pm #

      I’ve seen roofers do exactly what you describe – it’s quick, inexpensive and avoids disturbing the shingles when a proper rain collar isn’t available or the weather is cold and the shingles may crack.

      The petroleum-based sealant can attack the vent boot rubber. Check it in a week and again in a few months. I doubt it will crack immediately but will probably shorten the lifespan of the boot. Pick a warm day next Spring to replace the entire boot and add a rain collar.

  4. Dave November 29, 2011 at 4:06 pm #

    Thanks Bob,

    Certainly will do as you advise.

  5. Q.L. December 1, 2011 at 5:55 pm #

    Your post is very useful. The roofer that I hired used DAP® ALEX PLUS® Acrylic Latex Caulk Plus Silicone to seal the nail and gap between new vent boot and the pipe since he had to tear off the inner ring to fit in the pipe. Is this type of sealant sufficient enough?

    • Bob Jackson December 1, 2011 at 7:07 pm #

      Roofing applications are not listed in the “Suggested Uses” section of the DAP® ALEX PLUS® Acrylic Latex Caulk Plus Silicone technical bulletin.

      Whereas the SONOLASTIC® NP 1™ data sheet states under the “Where to Use” section (partial list follows):
      * Roofing
      * Wastewater treatment plants
      * Dams
      * Spillways and storm drains
      * Wetwells and manholes
      * Interior and exterior
      * Above and below grade
      * Immersed in water
      * Clay & concrete roof tiles

      A key product spec. in my opinion is the “Joint Movement Capability“:
      * +/- 35% for the BASF NP1
      * +/- 12% for the DAP ALEX PLUS
      because roofs expand and contract a lot between the cold nights and roasting hot sunny days.

      Given that the DAP ALEX PLUS product is not specifically rated for roofing applications and the wide variety of high performance roof-rated caulks available at roofing supply stores, I’d be disappointed with your roofer.

  6. Q.L. December 1, 2011 at 7:47 pm #

    Thanks Bob! Do you have any suggestion? Should I have him come back to take out the DAP Sealant and reapply the Sonoplastic NP1 to the nail heads?

    He did apply the TAM-PRO PREMIUM SBS ( under the bottom tab of those shingles that were raised to install the flashing.

    I did ask him to apply the TAM-PRO Premium SBS to the nail head as well but he said the DAP sealant is good enough.

    • Bob Jackson December 2, 2011 at 10:54 am #

      I’d have the roofer come back out, scrape off the DAP ALEX PLUS and reseal the nail heads. A dab of the TAM-PRO PREMIUM SBS Q-20 asphalt flashing cement on the nail heads would’ve been OK, so I wonder why he used DAP instead?

      The risk with the DAP caulk is it may peel or crack after a couple of seasons, but it’s not like it’s an emergency. It’s more about a doing a quality job and using materials that have comparable service lives. If rain water worked it’s way around the nail head, what’d you see is a water stained area under the roof deck from inside the attic, which could over time deteriorate as the glue in the OSB or plywood deck failed. If you had your roof reshingled down the road, the next roofer would say that section of roof deck needs to be replaced for an extra charge.

  7. Q.L. December 3, 2011 at 11:39 pm #

    I couldn’t find the Sonalastic sealant at the local store. I might order it online but that will take time. Can I substitute it with DAP® 3.0™ Advanced Blacktop & Roof Sealant with Kwik Dry® Technology ( being sold at Home Depot?

    For the DAP sealant, that can be scraped off even after more than a week after it was applied since the roofer prob can’t make it back till the coming weekend?

    • Bob Jackson December 4, 2011 at 8:30 am #

      The DAP 3.0 Roof Sealant will be fine for sealing the nail heads.

      > For the DAP sealant, that can be scraped off even after more than a week after it was applied
      > since the roofer prob can’t make it back till the coming weekend?
      A property of silicone & latex caulks is they are easy to scrape or rub off even when cured. Scrape off what you can with a small putty knife, the rest will rub off with your thumb. You need a clean surface for the roof sealant to adhere directly to the flashing.

  8. Q.L December 21, 2011 at 1:49 pm #

    Finally got roofer back to redo the job. Beside having him sealing around the edges of the boot, I also have the roofer apply the Sonalastic sealant between the area where the plastic part of the boot made contact with the vent PVC pipe as extra precaution. Will that be a problem? Does the chemical in the sealant cause any damage to the PVC pipe? Thanks!

    • Bob Jackson December 21, 2011 at 2:05 pm #

      > I also have the roofer apply the Sonalastic sealant between the area where the plastic part
      > of the boot made contact with the vent PVC pipe as extra precaution. Will that be a problem?
      It wasn’t necessary to apply sealant there. The boot is designed to hug tightly around the vent pipe to make a watertight seal. The sealant won’t prevent the boot from cracking over time due to UV light damage from the sun. The rain collar is your best protection *in addition* to the boot. The rain collar “floats” freely as it’s only attached to the vent pipe, experiences no stress due to heat contraction/expansion of the roof and shields the vent boot from UV damage.

      > Does the chemical in the sealant cause any damage to the PVC pipe?
      The sealant won’t bother the PVC vent pipe. PVC is very resistant to most chemicals.

  9. PA May 3, 2012 at 5:50 pm #

    Good article on replacing the flashing. I currently have lead flashings, but squirrels have chewed on them to the point where rain is getting through. Considering the Oatey. Any suggestions on which is better in this circumstance? Really don’t want to spend the money on lead flashings if in a year those rodents are going to chew through them again.


    • Bob Jackson May 3, 2012 at 7:10 pm #

      I have lots of gray squirrels that come up to the house all the time for the bird feeder. They’ve never bothered the plastic vent boots or PVC vent pipes. My guess is they like the soft lead flashing on your roof.

      You might try SquirrelGard™ – the product literature looks very convincing.

  10. Kris Barber June 8, 2012 at 5:39 pm #

    Thank you so much for posting! We have a 7 yr old roof that I recently discovered was leaking around not just one ventilation pipe, but 5! I don’t believe there was ever a boot type flashing put around the pipes from looking at the roof from outside, but that may be b/c the texas heat will melt them! I bought some of the “as seen on tv” flex seal and have considered putting that around the pipe from the inside, but not sure if that will keep the water out and/or cause more damage if the water has a place to pool up. It is not a big flow of water, its like a trickle but I can see daylight from the attic all around the pipe, so something is insulating, but not installed properly I am guessing. It seems we don’t get just a normal rain storms either…its 9 inches in a day or drought!! I keep asking my husband to fix this…I think we need to have a professional take care of it – the towel solution only goes so far! Of course, he is out of town and it rains heavily – murphys law!!

    • Bob Jackson June 8, 2012 at 5:51 pm #

      Funny… didn’t think anyone else would be using the knotted towel technique!

      Perma-Boot is a quick and simple DIY solution for leaking vent pipe flashing. I just had my roof replaced due to hail damage and installed these over the new vent pipe flashing as extra long term protection. My roofer said Perma-Boot works well and recommended the product. Cost is ~$19 and they’re available at Home Depot.

  11. PAC July 10, 2012 at 11:36 pm #


    Have you ever heard of rain water that goes down a vent pipe leaking out? What are the odds of the pipes elbow joint simply coming loose after 20 years and allowing rain water to leak out? This is what my roofer is suggestion.

    • Bob Jackson July 11, 2012 at 5:37 pm #

      I assume your roofer inspected the pipe boot on the roof and looked at the roof deck from inside to attic to confirm there’s no leak? Did the roofer replace the pipe boot or install a Perma-Boot just to be sure?

      It’s not unreasonable the vent pipe could have a leak at the elbow, however the elbow is also where water would drip off the outside of the pipe if the problem is with the vent boot on the roof. Do this to identify the leak source: Wrap the vertical part of the vent pipe above the elbow in a single layer of toilet tissue as a tell-tale, then secure it with a piece of tape. Place a pan under the pipe elbow with a piece of toilet tissue in the pan.

      Check the tell-tales during or after the next rain shower. If the tell-tale wrapped around the vent pipe shows signs of being wet, then water is running down the outside of the pipe from the roof and you have a bad vent boot. If the upper tell-tale is dry and there’s water in the pan, then the pipe elbow is leaking. A PVC pipe elbow is easy and inexpensive to replace.

  12. Sandy October 3, 2012 at 11:40 am #

    Thank you for this!! I am in ATL and after the last weekend of rain, I have discovered a leak in the roof where the bathroom vent is – very similar to the situation you described. There is no way I’d be able to do what you suggested by myself. But I’ve been getting crazy quotes, from $300 to $500 to $1250. I know it’s not a huge job, but am having trouble finding a reputable roofer. Do you have recommendations for the ATL area?
    Thank you again!

    • Bob Jackson October 3, 2012 at 12:14 pm #

      Call Dr. Roof at 770-552-7663 for repairs in the Atlanta metro area.

      $300 to replace a cracked pipe boot could be reasonable because a small job just to replace the boot may incur the minimum repair charge.

      On the other hand $1,250 could be warranted if the pipe boot leak caused the roof deck to rot necessitating a major repair to tear off the shingles, replace the rotted section of deck, install new felt and shingles. Can you inspect the roof deck around the vent pipe from inside the attic?

  13. Sandy October 3, 2012 at 12:36 pm #

    Wow! Such a speedy reply. Actually, I think the decking has to be replaced because there’s a spot that is black (mold?). I think it’ll be about a 3 square foot piece that needs to be removed, then resealed, then shingles replaced. I had two roofers come out to look and this is what both said. One was at $500, the other $600. So I’m pretty sure this is the problem. I figured I ought to have a couple more quotes, and called a few places with this description. That’s where the $350 and $1250 quotes came from –just over the phone. I’m learning a ton as I go through this, but just don’t trust my decision-making completely. Your site is incredibly helpful to at least learn about how houses work! Thanks again.

  14. Marc June 10, 2013 at 2:50 pm #

    Just read this entire post. I must say over the last 3 years, I have personally repaired so many things I would not have in the past, due to people like you, Bob, writing excellent posts and providing wonderful pictures. I have the Identical problem you show. I do live in NY, but part of my roof with the bath vent is constantly southern exposed, and the home is 12 years old which I now know must be the average lifespan for the rubber on these flashings. Got a bucket under it for now, since its raining, but as soon as things clear, heading over to Lowes to get the needed repair items. Your post has helped me big time, and you have saved me a lot of $, especially needed with economy we’re in now. Thank you, Thank you, Thank you!!!!

    • BobJackson June 10, 2013 at 5:37 pm #

      You’re welcome!

      You might also consider Perma-Boot to protect the rubber vent boot flashing from the sun and squirrels.

  15. Teri July 11, 2013 at 6:17 am #

    We had a contractor come out yesterday because of a leak showing on our bathroom ceiling and wall. With the vent being right there also, he figured a good guess would be the vent stack or flashing. After he went up on the roof he said the flashing was fine but didn’t see any sealant on the vent stack. We live in Florida so what would be a good sealant to get because of our hot and humid weather. He said he would do the sealing plus seal all our other vent stacks for $400. My husband thinks he can do it and for a lot less???? And would we just being sealing the seams of the vent stack?

    • BobJackson July 11, 2013 at 6:05 pm #

      > After he went up on the roof he said the flashing was fine
      > but didn’t see any sealant on the vent stack.
      The rubber boot should not be caulked or sealed around the roof vent pipe. Only the nail heads driven through the tin flashing base are sealed. The rubber squeezes the vent pipe to make a water tight seal. Which makes me wonder, are we talking about a plumbing vent pipe or a gas flue vent?

      Let’s assume the problem is a roof plumbing vent as shown in the project and you have an asphalt shingle roof (many Florida homes have clay or cement tile roofs). Have you been in the attic and inspected the roof decking and vent pipe for signs of water leaks or stains? This would confirm the vent flashing is leaking either because the vent boot is cracked or perhaps rain water is leaking around an exposed nail in the tin flashing. If there’s any question the flashing is leaking, have it replaced. Also replace the other plumbing vent boots because those are likely near the end of their useful lives.

      Install a Perma-Boot (available at Home Depot) to protect the rubber vent boot from the sun and elements.

      $400 for “sealing” instead of doing a proper job and replacing the vent boots strikes me as wasteful. You can find reputable roofers on Angie’s List or Look for GAF and/or CertainTeed factory certified roofers who have been in the business 5 years or longer.

  16. Dalton July 16, 2013 at 11:30 pm #

    I had a house in Baton Rouge that had the original lead flashing on the plumbing vent pipes. When the trees and bushes got tall enough for the climbing wildlife (cats, squirrels, racoons, possums, etc.) to get on the roof the lead flashing was eaten off right down to the nails.
    The cheap plastic stretch fit slip on vent covers will crack after a few years in the Louisiana sun.
    I use 2 of them with the first one anchored normally and the second one pushed down over the first to act as a sun shield.

    • BobJackson July 17, 2013 at 8:40 am #

      My roofer said he will do the same if a rain collar isn’t available or as a quick fix if it’s raining.

      When I later had my roof replaced, I had the roofer install a Perma-Boot (available at Home Depot) over the standard roof vent flashing. Perma-Boot can be installed even if it’s raining. I wonder if Perma-Boot would resist your wildlife problems?

  17. Arielle July 10, 2014 at 3:22 pm #

    In hindsight, the best solution is to use a long lasting roof flashing the first time (not rubber or pvc), but I had the same problem with my roof. SBC has a rain collar that you can add to cover your damaged boot or if it needs to be replaced, they have a pipe flashing that will fit your vent pipe and includes a collar. It’s completely stainless steel and cost me about $75 for both parts including shipping. Good luck!

    Rain collar:
    Pipe Boot:

  18. max November 2, 2014 at 12:07 pm #

    Had an estimate to replace 3 roof vent pipes with the Perma -Boots wants to charge me $600.00 ( $200.00 per vent ) is this too much??

    • Bob Jackson November 2, 2014 at 3:39 pm #

      The answer is “It depends.”

      Is the roofer going to simply pop-on a Perma-Boot over the old vent boot and be done? If so, then $200 per vent sounds high. On the other hand, if the roofer will replace the old vent boot flashing then install Perma-Boot then it’s a more reasonable price. If I were hiring a roofer I would definitely have the old vent boot flashing replaced before installing Perma-Boot so you know everything is good. Other factors like a high steep roof with difficult access can affect the cost.

      The best approach to determine what’s a reasonable price in your area is to request three quotes from reputable roofers that have been in business for at least 3 years, have an A+ Better Business Bureau rating and provide a warranty.


  19. Tony November 5, 2014 at 5:40 pm #

    Thanks for a detailed article, I’m in coastal British Columbia just north of Seattle, weather is wet/rainy in winter with very little snow. Sun and temperature are probably the harshest factor up there, summer air temps reach 30+C/80+F and it’s hotter on the roof with radiant heat. We’ve had minor leakage around the bathroom starting about 3 years ago. Many trips up into the attic showed nothing but the blistering paint in the bathroom keeps coming back. Lately, on a couple of occasions with really driving rain, there are drips of water running down the wall. Thanks for your pictures, turns out our stack boots were cracked, they were 8 years old. I wasn’t very happy when the roofing contractor slapped on the rubber flashing, I could see him abrading the rubber on the rusty iron stack, doomed to fail. The old boots were lead and never leaked in 45 years.

    Today I installed a temporary rain shield to keep rain off the stack while the 3 Perma-Boots I ordered online get shipped, My temporary solution are lengths of 4″ corrugated drain pipe with a loose fitting cap on the top end. I have a length of wire to hold the rain shield to the vent to prevent the wind from blowing it off. Nothing is airtight so the vent will still get air but the stack pipe is shielded from being hit directly by the rain and water shouldn’t run down the pipe now past the cracked and slit boot. Cost was $8 for the 10′ of drain pipe, $12 for 3 caps (more than the pipe!!) and about 8′ of galvanized wire. I popped in rain gutter wire leaf guards to create the airspace above the top of the stack pipe. The drain pipe cap sits on the leaf guard so that the cap doesn’t close off the vent opening. The contraption actually looks pretty smart up there.

    Anyone who is getting a roof done should specify no rubber boots be used by themselves. Doing it right for the long term is minor added cost of under $100 for matorials compared to the thousands $$ for the roof job.

    • Bob Jackson November 5, 2014 at 7:03 pm #

      Thanks for sharing your story. If you’d like to send a photo of your improved rain shield to bob[at], I’d be happy to include it in your comment. Replace the [at] with the @ symbol.

      I agree – rubber vent boots don’t last and should never be used by themselves.


  20. Tony November 17, 2014 at 12:44 am #

    I finished the job today, HomeDepot Canada doesn’t stock the perma-boot but they will ship to Canada free from Raleigh, North Carolina USA. For added insurance I bought 3 thermoplastic boots, cut off the flange that sits on the roof and slide these over the stack pipes and over the old boots before installing the Perma-boot over top. Maybe overkill, but for the extra $30 for 3 plastic flanges it’s well worth it if I don’t have to repair the bathroom and kitchen ceilings again.

    For my Big-O rain shields, the modification i made was to cut slots into the bottom of the vertical tubes as the tubes seated tight over the existing boot on the roof and held collected rain water, it didn’t leak out as I expected so needed drain holes.

    On one stack I needed to extend the pipe length. I used an ABS plastic coupler and length of 3″ ABS pipe. The inside of the Perma-boot needs some ridges shaved off so the coupler would fit inside. A wood chisel did the job nicely.

    Homeowners, if your roofing contractor shows up with theromplastic/rubber boots, tell them to use metal or lead caps or perma-boots. Save yourself an expensive repair for a wet ceiling and possible mould infestation in 5 years.

  21. Tony November 30, 2014 at 12:39 am #

    Just to finish the story about my trials and errors with the leaking boots. Ideas evolve and sometimes come full circle. Next time I’d ditch the Big-O temporary rain covers and go with sliding on some new thermoplastic boots until the Perma-Boots arrive (about 2-3 weeks shipped from HD in the USA). Initially HD wanted $22+taxes each for rubber boots, almost the same cost as each perma-boot, I didn’t want to spend $75 on a temporary fix. Shopping around and going to a real building supply store (not a big box home renovation store) I found boots with flanges for $8 each. So for 3 stacks, $24+taxes was reasonable, about the cost of by Big-O solution, and much faster, less waste (cut the flanges off), and more water tight than the Big-O rain shield. My preferences: lead first, metal second, perma-boot with rubber boot as insurance third. Never again rubber boots alone.

  22. paula June 1, 2015 at 10:40 am #

    I climbed up on the roof – with the roofer to see for myself. He pointed out the vent pipes were caused the leaks. Around the primeter of the roof wall, i saw roof material bulging all around the roof with lot of black tar over the seams. He said he would fix the bulges..apply copping metal and cap sheeting around the wall.. then hot mop the roof then pour granules over the tar for $5,000. Now that I’ve done my research. It seems to me ALL my vent pipes need to be replaced but he didn’t mention THAT. I have pix of my vents, pretty bad.

    • Bob Jackson June 1, 2015 at 9:58 pm #

      I would like to see your roof photos. Send them to bob[at] replace the [at] with the @ symbol.

  23. Edward Guldner March 8, 2016 at 2:40 pm #

    I have two separate and distinct situations. First one is the roof penetration of concentric PVC pipes for intake & exhaust of a high-efficiency gas furnace…it seems that the Perma Boot solution will not work here due to the PVC cap that keeps the two pipes centered. The second one is that all of our plumbing vents are cast iron…Perma Boot is only for PVC pipe vents. So, any solutions?

    • Bob Jackson March 9, 2016 at 2:10 pm #

      Perma-Boot is designed for Drain Waste Vents (DWV) which are part of the sewage plumbing. Gas Flue Vents (technically called “Type B Gas Vent”) that serve a gas furnace or hot water heater require a metal flashing system. This project describes how my gas flue vents were replaced during a roof replacement.

  24. Edward Guldner March 9, 2016 at 3:59 pm #

    I believe you missed an important point in my question. The gas furnace is a high-efficiency, condensing model which uses PVC for the ‘flue vent’. This is not the typical Type B Gas Vent. It is very common to use PVC for intake as well as venting of this type of furnace; but to further complicate my issue, is the fact that there is a PVC hood/cap that fits over the concentric PVC pipes; so this would preclude the installation of the Perma-Boot with the cap that goes over the top of the vent stack. In addition, since this is venting gas fumes, I assume there is a code requirement for the minimum height of this vent above the roof, and that is probably much taller than any Perma-Boot assembly.

    • Bob Jackson March 9, 2016 at 5:30 pm #

      Does your gas vent look similar to the DuraVent PolyPro vent? Click on the “Typical Installation” tab on the PolyPro page for installation diagrams. The PolyPro Installation Instructions are very informative, too. If the vent is leaking it may just need new gaskets, replace the cone flashing or other parts.

      Polyflue and is another plastic flue vent manufacturer.

      > I assume there is a code requirement for the minimum height
      > of this vent above the roof, and that is probably much
      > taller than any Perma-Boot assembly.
      IRC G2427.6.3 (503.6.4) Gas vent termination defines the required gas vent clearances above the roof, which is dependent upon the roof slope. Check with your Building Dept. for potential amendments.

      BTW – for those cast iron plumbing vents Perma-Boot fits pipes up to 4 inches in diameter.


  25. Remy July 25, 2016 at 1:39 pm #

    I had a roofer replace all the pipe jacks but he insisted that if you put roofing nails on the flashing that it will cause a leak. We argued for hours as I felt roofing nails and sealant are a must. And he continued to argue that I was wrong. He left without putting nails and sealant. He insisted he knows better with 45 years experience. Was he right?

    • Bob Jackson July 26, 2016 at 12:57 pm #

      I’ve pondered the same issue. If a quality sealant is used on the roof nails there shouldn’t be problem. Properly cut shingles should cover the roofing nails for added protection.

      The best solution is install a layer of ice & water shield self-stick rubber membrane over the roofing felt, followed by vent flashing. The ice & water shield will seal the roofing nail penetrations. Of course, sealant should still be applied to the nail heads. The ice & water shield can be worked under the existing shingles by temporarily removing the nails from a couple of singles, or a section of shingles could be removed and replaced. Although replacing weathered shingles often causes a color mismatch with the new shingles.

      See Hail Damaged Roof Replacement: Part 5 – Plumbing Vents for details.

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