Rolled Asphalt Installation Instructions

[Mark P]

I am looking for the instillation instruction for Rolled Asphalt. I am especially interested on how it should be installed when there are parapets on the house. I understand the covering will trap moisture inside the bricks causing their decay, but how should it be done. Are termination bars used in this case? I’ve already told the buyer the roof was installed unprofessionally and in my opinion will not last very long; that there are repairs that need to be done now. But I want to learn some more on how this should be installed on a house like this. This house is a complete mess from head to toe.

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[kurt]

Are you sure that's rolled asphalt? It looks like it could be granulated mod bit(?). Rolled asphalt won't "do" a lot of the stuff the installer is making this stuff do.

"Yes" to termination bars/counterflashing bars. "No" to wrapping it up over the parapet.

Where's the coping?

Baseline, tear it all off and start over.

[Mark P]

Thanks Kurt,

It is granulated modified bitumen, I should have know better, I make that mistake too often because I see very few of these. I'm going to swing back by this evening to take a second look at a few things. This is turning into the report from hell, a real monster of a house. I'm also sure it is haunted, but I'm going to let that be a surprise to the little lady buying the home.

So help me out here - so I don't make the same error again how exactely do I tell the difference between rolled asphalt and granulated modified bitumen?

[BornaRoofer]

The roof looks like its unsaveable. I couldn't list all the things I see wrong. Possibly reflashing and proper metal details throughout would give it a few years.

Your supposed to go over the parapet and install a coping.

Bar is used when your terminating to a wall you cant go over the top of or a wall end.

I recommend surface or reglet metal not bar though.

The field sheet goes 4" up past the cant then a separate flashing up and over the wall and 4" onto the field.

You can tell if its a mod bit by the texture of the bitumen. Its rubbery and somewhat elastic if you push or pull on a piece.

[inspect4u]

Looks to me like someone said "What the hell have I gotten myself into?" packed up and left!

Mike M

[kurt]

Originally posted by AHIS

So help me out here - so I don't make the same error again how exactely do I tell the difference between rolled asphalt and granulated modified bitumen?

Basically, rolled mineral is 90# stuff, you can tear it easily w/your bare hands.

Modified is about 1/8" thick, and it's impossible to tear apart w/your bare hands.

There's lots of other ways to tell, but that's the simplest and quickest way.

Understand, the thing about not wrapping it up over the parapet is my thing, not necessarily the industry thing. I look at hundreds of these a year, and I am adamant in my position that it shouldn't be wrapped over the wall. If it is wrapped over the wall, there has to be some means for ventilation. I've seen full wraps work OK if there are enough breather vents. If there's no vents, the wall goes to hell.

Hot moves to cold, wet moves to dry. Warm moist air migrates up, and then to the perimeter, where the moisture condenses between the membrane and the parapet wall, soaks into the wall, and demolishes it from freeze/thaw. I see hundreds of buildings a year that have completely demolished parapets from this phenomenon.

I have dozens of slides showing this. If I get inspired, I'll dig some out & post 'em.

[Chad Fabry]

Some instill beliefs, others install roofs.

[ozofprev]

Thank you Chad. I get tired of being the only ass around!

[]

[Jim Katen]

Put me in Kurt's camp regarding the don't-run-the-membrane-up-the-parapet issue. If you do, you're putting a vapor barrier on one side of the brick and leaving the other open to the rain, sun, snow, whatever. The brick doesn't seem to like that.

Your picture #4 shows the mortar decay on the outside of the parapet.

As for the rest of the roof, it's a disaster. I know some roofers who might be capable of saving it, but none of them would do it. Who needs to take on the liability of a job that was done by morons?

- Jim Katen, Oregon

[Mark P]

Originally posted by Chad Fabry

Some instill beliefs, others install roofs.

Okay, got it. I usd to live on a military installation where the instilled ....

[BornaRoofer]

I understand your concerns about sealing up parapet walls but I have to disagree.

Whats going to keep the water out of the top of the wall?

A metal cap with a caulk seam every 10'? Old clay crock?

Copings leak and are the first thing to go in a storm something needs to seal the open top of the wall.

Ive personally inspected and installed thousands of flat roof systems and some did have the conditions you talked about but it wasn't from the flashing sealing up the wall. It was from unsealed walls on the outside or condensation.

Walls are supposed to have waterproofing behind any brick veneer with weep holes and block has to be painted or sealed to prevent damage. Condensation is not a roofing issue its a ventilation /hvac issue.

Now if you had a specific designed vented parapet that may be different but ive never seen one.

[kurt]

Well then, you need to come to Chicago to see one.

Coping keeps the water out of the top of the wall. Clay tile, sealed w/good (what constitutes "good" requires a entire page single spaced) mortar, works fine. There's only about, oh, say, 150,000 of them in this old masonry city. Maybe another 100,000 w/stone coping. A few dozen thousand w/metal coping.

Those aren't bad models for making assumptions. My observation is coping works.

When coping doesn't work, there are very obvious other problems, like some dork didn't install it right, or there's no flashing under it, or some other moron has smeared a perfectly good lime based mortar w/ Type S and totally demolished it, and on and on......

Yes, it was from the flashing running up the wall. No, it wasn't because the wall wasn't "sealed" (Oh Lordy, the pain, the pain), and it most absolutely positively is from condensation just like you said; condensation on the inside between the membrane and the parapet.

The idea that block has to be "painted or sealed" to prevent damage is simply not true. The idea that masonry has to be sealed is what folks think that don't understand how moisture works in masonry.

The current fascination w/"sealing" block has everything to do w/crappy material installed improperly, and nothing to do w/good masonry practice. Yes, there a lot of block buildings in Chicago that we're giving the "Modac bath" to because there is no other way to waterproof them, but the problem originated from improper installation, not some strange idea that masonry has to be sealed.

The single largest problem w/masonry is there's about 11 people in North America that seem to understand the differences in mortars, block, brick, and methods of installing them in assemblies that manage moisture.

Go to the DeGruchy site, read up, and get back to us w/your new found knowledge.

And, I beg forgiveness for my completely overbearing arrogant tone. I live in a beautiful masonry city that is being demolished by ineptitude and misplaced ideas about sealing masonry, "tuckpointing", and all manner of idiotic ideas that the skilled masters that assembled this town would be horrified by.

Masonry, as an actual skilled trade, is dead. There are few practitioners that keep the dream alive. They must be listened to.

[Jim Katen]

Originally posted by BornaRoofer

I understand your concerns about sealing up parapet walls but I have to disagree.

Whats going to keep the water out of the top of the wall?

Properly made metal copings with flat-lock or standing seams.

A metal cap with a caulk seam every 10'? Old clay crock?

Copings leak and are the first thing to go in a storm something needs to seal the open top of the wall.

They only leak or fall off in a storm if they're poorly made.

Ive personally inspected and installed thousands of flat roof systems and some did have the conditions you talked about but it wasn't from the flashing sealing up the wall. It was from unsealed walls on the outside or condensation.

It's from having one side of the parapet exposed and the other covered. Condensation forms on the inner face and the mortar falls apart. Sealants are a sham.

Walls are supposed to have waterproofing behind any brick veneer with weep holes

True, but we aren't talking about brick veneer. Well, Kurt & I aren't anyway. The parapet in the original post is all brick. If it were brick veneer with a wood stud wall behind it, then I'd agree with you.

and block has to be painted or sealed to prevent damage.

In my experience, paint or sealant on block causes more problems than it solves.

Condensation is not a roofing issue its a ventilation /hvac issue.

Condensation is a physical phenomenon that occurs when water vapor hits the dew point. It doesn't only affect certain trades. Sometimes the cause of condensation problems is lack of ventilation. That's exactly what happens when you run a vapor barrier up one side of a brick wall. HVAC systems have zero effect on parapets.

I'd agree with your way of doing it if we were talking about wood or steel parapets, but it's a bad way to go with brick parapets.

- Jim Katen, Oregon

[BornaRoofer]

I apologize I guess I didn't realize you meant you only recommend not going up and over when its 100 year old brick on both sides of the parapet. So 95% of everything built in the last 50 years should be flashed up and over as the entire roofing industry requires. Rarely are buildings built with brick on the inside of the parapet anymore. Its all block with waterproofing 90% of the time.

Unfortunately the guy that roofed most of those buildings 100 years ago also flashed up and over.

And you have to flash the wall at least 8" up so your still going to get the condensation at the base if your wall/bldg has excess moisture in it. If theres water vapor under the roof anywhere its not good.

Hvac systems have zero effect on parapets but they do effect humidity.

[kurt]

No apologies necessary. You seem a reasonable sort.

I see dozens or a hundred new buildings that are solid masonry every year. Cavity wall and block.

Block is definitely going out of favor due to the multiple problems w/water penetration. Sealing the block is a nice idea, but honestly, of the hundreds I've seen, it doesn't do squat. Nada. The folks that really believe in sealants are the mfg's. and folks that apply it.

The only thing I've seen that is worth a damn is Modac. It's like GoreTex paint for concrete block. It's got an ASTM perm of about 8.4%, so it breathes pretty good.

I hate block. A total mistake. If one is building solid masonry, it should be cavity wall. At least then one has a chance at water management.