# Question re: best roofing material for my situation.



## Amovida (Oct 18, 2011)

Hello to all and thanks in advance for helping with my question-

My lovely mother didn't put anything aside for retirement and as a bootstrapping method I am fixing/flipping a residential single family home to help her out. The project is largely finished after 5 months (interior remodel by me) and overall the project looks like it will be win. 

Looming on the horizon is the roof which currently leaks at the location of 3 different skylights. It is a 20 square flat roof with what I believe to be modified bitumen over the decking going about 12 inches up the parapet walls. The bitumen is pulling back from the parapet in a lot of places and while not brittle, the material is not nearly as flexible as new bitumen. The roof is ballasted by a hell of a lot of pea gravel (2'' deep). Under the pea gravel it looks as if the top of the bitumen was tarred as 5% of the gravel is embedded in roofing tar.

I have managed to tile set around jacuzzi tubs, hang cabinets, repair plumbing, install interior trim and while not trying to boast feel my work has come out as well as most professionals. I have been doing property management on the sharp end (meaning holding the tools) for over 20 years. I have read the opinions of the roofers on this forum and have been impressed by the high level of honesty, straight talk and professionalism. I understand that if I put in half a repair I'll only get half a solution. 

I have read several hours worth of material on this site and it looks as if PVC and TPO have distinct advantages. I've also read a fair amount about possibly "extending" the life of the roof with a coating such as Conklin, Gaco or Mulehide...but I'm not sure how that might work given the "tar and rock" mopped over the bitumen. I've walked two roofs with liquid coatings, one by Conklin and the other what felt like an acrylic caulk material. The Conklin looked great, durable and showed no signs of wear while the other had cracked in areas that puddled. I have a pressure washer, and access to a seaming/welding machine for TPO. 

Having said all that I would like some advice as to if there is a roof that I can install with my and paid labor to save some bucks and honestly help my mom. Can I install a TPO or PVC roof myself, or is learning to join the seams and go around vents, etc. to difficult? If not, is there another roof system I can install? Or should I use Conklin or a like roof coating assuming I can go over the embedded rock? I am in the state of New Mexico. Thanks again to all for your time and expertise. Sean


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## Grumpy (Oct 29, 2008)

You did an interior remodel BEFORE fixing a leaky roof?! 

It's probably not bitumen if it has gravel. Most likely is is a type of BUR called "tar and gravel". 

TPO or PVC will require soem kind of recovery board or perhaps a polyester seperator matt or easier yet, a fleece backed product to provide a seperation between the new membrane and the asphalt. That is assuming you can easily remove all the gravel. I always recommend a tear off when the budget allows, if you've been reading this forum you'll know why. I would not recomment either TPO or PVC as a DIY membrane and would encourage you to contact local licensed and insured professional roofing contractors.

Liquid applied systems are all about the prep work and the condition of the existing roof. I don't mind coating systems, but hate when salesmen tout them as fix all solutions, because truth be told they are very particular and require an overall decent roofing system to be installed upon. Again you'd need to get rid of all the gravel... well one manufacturer I used to work with had a spec to encapsulate the gravel but the price was soooo outrageous a tear off was cheaper.

Any acrylic, including conklin will fail at puddle areas. This is why many manufacturers make solvent based coatings, as well as urethane based coatings. Either will stand up reasonably to puddle areas, but would require perhaps an additional layer of product.

If you insist on doing it yourself look into EPDM. Learn more about your flat roofing options.


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## Amovida (Oct 18, 2011)

Grumpy...thanks for your response, I've definitely learned a lot from your posts. Yeah, interior remodel first...with careful attention to leaks. I've run around w more than a few buckets and cut evenings short if I thought it was going to rain. I think the existing roof is bitumen but I'll post a photo. The bitumen in the couple places I pulled back the gravel had tar on it and rock stuck in that tar. I'll post two photos..one of the overall roof and the other where I swept back the pea gravel. I think you're right about hiring a licensed roofing professional and I have in the past. That's why I don't know that much about roofing. However, this time the budget has me doing the repair/replacement. 

I read the information on your site which is layed out very clearly. Is there a roofing solution either Single Ply or Elastomeric that could go over the tar/pea gravel after I removed the majority of pea gravel. Do I have any options besides a complete tear off? You can't see it very clearly but that dirt in the bottom of the second photo is on top of tar and gravel that doesn't want to move, on top of the roofing material. thnxs Sean


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## Grumpy (Oct 29, 2008)

Looks like a built up roof with pea gravel imbedded and was either flashed in or later repaired with modified bitumen (or perhaps 90#). And then repaired again with roof cement because the roofers who installed the modified bitumen flashing were retards and forgot the termination bar.


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## 1985gt (Dec 21, 2010)

Walls are generally flashed with mineral surfaced mod bit. Then the gravel is applied. They did use anchor bar at the tops of the flashing then just mastic over that. (wrong) 

You can scrape down smooth tear off wall flashing then coverboard (of your choice) then any roof system you choose. I wouldn't not attempt to coat it, unless you remove the gavel its a waste of money. I know of and have seen people put a coverboard over the gravel then roof it, I personally don't like this method and would never use it. It makes for a lumpy roof no matter how you do it. 

I will caution that with all the penetrations and such up there this goes beyond the Saturday afternoon shed roof. It takes a bit of time and know how to do these properly. The last thing you want is to pay for all of this material install the roof then have it leak again.


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## 1985gt (Dec 21, 2010)

Oh and I will add I am 90% sure that is all ready a recovered roof. Depending on age the bottom roof layer could be pitch. The one way vent between the two skylights is a give away. It vents the two different layers of roofs. I don't know about your area but here we could not recover this roof again. 2 layers max. 

Looking closer at the pictures it appears at some point they put tapered insulation (thats a good thing).

May look in to tearing it all off tapered insulation and any single ply or another BUR. Have a contractor do it and get a transferable 10 year or so warranty. You will get a good fair bit of your money back I would guess.


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## Amovida (Oct 18, 2011)

1985gt and Grumpy- Thanks guys...the big picture is getting much clearer. You may want to give up roofing if you can tell all these things just from my bad photos...might be time to master the next thing! 

Looks like you're also right about there being two roofs and I have been told two is the maximum here. So I guess I still have two choices.

1. Tear it all off..put down tapered EPS foam....coverboard....and then I'm thinking TPO adhered and mechanically fastened under the seams. I've got a roofing contractor that's going to help out so I do it correctly. I'll use either Conklin or Mulehide which I guess is made by Carlisle.

2. Option #2 multi-coat roof coating. Once I remove the ballast (pea gravel) and am left with tar and embedded rock (lumpy) will the coating adhere to this? Will it look like quite a mess with the uneven rock/tar surface when it's done? Do you have brand names for this that are better than others? I know Conklin makes one...not sure it'll stick to that surface?

Look forward to your answers and thanks again for your help.

Sean


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## 1985gt (Dec 21, 2010)

Amovida said:


> 1985gt and Grumpy- Thanks guys...the big picture is getting much clearer. You may want to give up roofing if you can tell all these things just from my bad photos...might be time to master the next thing!
> Thank you. I know Grumpy has a lot of experience and I do also. I have been in this line of work for around 10 years now I was an installer for 8 of those and ran a crew for 6 or so of those year.
> 
> Looks like you're also right about there being two roofs and I have been told two is the maximum here. So I guess I still have two choices.
> ...



Your welcome glad to help.


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## Grumpy (Oct 29, 2008)

EPS might not be allowed on a wood structure, check your local fire codes. I know several companies around here use it though, regardless of the codes.

Amovida, It's a roof and is one of those things that if you are going to do, you really should do right. Strip it down to the substrate. Reinsulate, either the ceiling or the roof, as necessary. Ventilate if the ceiling is insulated. Install something reflective, white EPDM, TPO or PVC would all be fine choices. Mechanically attached would be cheaper, and our go-to on most residential projects. Adhere the walls, don't skimp on the accessories. Yes it'll cost more than going over, but will cost less than a coating. 

Coating will never adhered to the dirt and you will never get all the dirt off the roof. The coating will essentially become a floating membrane. I can tell you from experience that rocks highly distubr coating and make it very very troublesome to get a perfectly uniform membrane. IN other words expect leaks in short time. 

Stick with manufacturers such as Firestone/Genflex or Carlisle/Versico who make their own product. IB has a great reputation but don't make their own product. There are alot of other smaller manufacturers out there that make good product but if you don't know which ones you are rolling the dice.


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