Thread: Modified Bitumen Roofing

I have concluded my hypotheses on a subject home.
There have been several diagnoses by leading defect recognition specialist that are absent definable prognoses. None what so ever by the way.
Much money and time spent.

Just finalizes subjects and recommendations.

1: Home is exhibiting many symptoms. All retailed to moisture intrusion.
I use Newtons three laws.
Subject; building circa, construction, materials, what has been recently restored/replaced/maintained and the environment.
Many symptoms affecting the home owner.

Roof:Modified Bitumen Roofing.
A grid of blisters ><3" wide, ><1" high covering the roof.
Outdoor relative humidity 31.3%
Attic relative humidity 57%. Taken at both vents. (That's another story.)

Hypothesis anyone?

r1a.JPGr2a.JPG

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It could be that the under laying roof board got wet (rain storm) prior to installation of final layer? Trapped water can cause lifting.

Building is circa <1940's
Typically I see slope to the drain.
Slightly sloped <1%.
Plenum roof assembly.

Modified roofing systems up until 2 years ago are suspect for longevity IMO.
Like shingles, bitumen was replaced with polymers.
Case action suits incurred.
I suspect Modified will do the same.

Ray, Members, Please excuse the post management.
Awaiting members like yourself to chime in.
You are correct to say, infiltration
How does moisture move in/through buildings?

More to come in other sections.

Originally Posted by Raymond Wand

It could be that the under laying roof board got wet (rain storm) prior to installation of final layer? Trapped water can cause lifting.

That was my second thought, my first thought was that the new roof is leaking (it's an either/or/both possibility).

Really not enough information or photos to go on.

Roof covering is currently modified bitumen, right?

Is roof covering applied over underlayment/base sheet direct to deck or over insulation board?

If over insulation board, was insulation board replace when roof was replaced?

Many questions, no answers.

Is this some kind of HI game or something?
There isn't anywhere near enough information or photographic detail to begin guessing.

And I'm not sure what the complaint was that brought you out there.

Dom.

Originally Posted by Dom D'Agostino

Is this some kind of HI game or something?
There isn't anywhere near enough information or photographic detail to begin guessing.

And I'm not sure what the complaint was that brought you out there.

Dom.

Not a game Dom.
Sorry if you think it is. Certainly was not my intentions.
Trying to getting members with roofing expertise involved.
Hypothesis, built from thinking outside the box field of vision.
Roof is not leaking.

1930's home.
1:Flat roof. Expect planks.
2: Plenum space. Not vaulted as mentioned. Vaulted attics can exhibit moisture problems.
3: True parapet.

Modifed roofing. Foam underlay buttoned down.
1 ply and 2 ply system

Blisters are a symptom of membrane roofs that have been applied over damp surfaces.
As the moisture dries, it expands to a vapour and dislodges the membrane from the substrate.

What part of the structure is 16 OC?
48" and 96" long ridge blisters.

Anyone has articles on poor performing modified roofing material.

r1c.JPG1r4.JPG

I suspect there is ten-test, modified rolled on top.

No signs of water infiltration.

Either way there should be no ridges at the seams.

Originally Posted by Raymond Wand

Either way there should be no ridges at the seams.

Ray, Jerry, Dom, please excuse not recognizing your posts.

Moisture.
Wet decks are prime suspects.
I will perform a cut test, but only at the owners request.

Dislodged and loose fitting plumb stacks.
I was hoping, or wishen as Jerry would say, for that reply.

Report about to be delivered.

Originally Posted by ROBERT YOUNG

I have concluded my hypotheses on a subject home.
There have been several diagnoses by leading defect recognition specialist that are absent definable prognoses. None what so ever by the way.
Much money and time spent.

Just finalizes subjects and recommendations.

1: Home is exhibiting many symptoms. All retailed to moisture intrusion.
I use Newtons three laws.
Subject; building circa, construction, materials, what has been recently restored/replaced/maintained and the environment.
Many symptoms affecting the home owner.

Roof:Modified Bitumen Roofing.
A grid of blisters ><3" wide, ><1" high covering the roof.
Outdoor relative humidity 31.3%
Attic relative humidity 57%. Taken at both vents. (That's another story.)

Hypothesis anyone?

Originally Posted by ROBERT YOUNG

Building is circa <1940's
Typically I see slope to the drain.
Slightly sloped <1%.
Plenum roof assembly.

Modified roofing systems up until 2 years ago are suspect for longevity IMO.
Like shingles, bitumen was replaced with polymers.
Case action suits incurred.
I suspect Modified will do the same.

Ray, Members, Please excuse the post management.
Awaiting members like yourself to chime in.
You are correct to say, infiltration
How does moisture move in/through buildings?

More to come in other sections.

Originally Posted by ROBERT YOUNG

Not a game Dom.
.
.
Roof is not leaking.

1930's home.
1:Flat roof. Expect planks.
2: Plenum space. Not vaulted as mentioned. Vaulted attics can exhibit moisture problems.
3: True parapet.

Modifed roofing. Foam underlay buttoned down.
1 ply and 2 ply system

Blisters are a symptom of membrane roofs that have been applied over damp surfaces.
As the moisture dries, it expands to a vapour and dislodges the membrane from the substrate.

What part of the structure is 16 OC?
48" and 96" long ridge blisters.

Anyone has articles on poor performing modified roofing material.

Robert,

I suspect what Dom was referring to was the seemingly cryptic way you posted, and, yes, you did say "Please excuse the post management.", however, even given that, your posts were more like a checklist reporter's report, nothing narrative describing or explaining what/why you were called out, what/why you saw what you saw that caused you to come to your conclusions, and then you added "Roof is not leaking." - as though that is a fact you know.

If you know that the roof is not leaking, then you know a lot more information about that roof than you are sharing with us ... which makes it a guessing game on our part.

That's almost like showing us a photo of a duck's bill, and a photo of webbed feet, then another photo showing a beaver's tail ... then asking us what kind of animal that is (yeah, I know what that animal is).

When someone posts something, they are 'painting a picture' for the rest of us to 'see', and unless the picture is complete enough, all we 'see' is the 'white space' between the words ... you need enough words to paint a complete enough picture for us to 'see' it.

Originally Posted by Jerry Peck

Robert,

I suspect what Dom was referring to was the seemingly cryptic way you posted, and, yes, you did say "Please excuse the post management.", however, even given that, your posts were more like a checklist reporter's report, nothing narrative describing or explaining what/why you were called out, what/why you saw what you saw that caused you to come to your conclusions, and then you added "Roof is not leaking." - as though that is a fact you know.

Roof:Modified Bitumen Roofing.
A grid of blisters ><3" wide, ><1" high covering the roof.
Outdoor relative humidity 31.3%
Attic relative humidity 57%. Taken at both vents.
Hypothesis anyone?

I disagree.
Reams of data to extrapolate a hypothesis.

Originally Posted by Jerry Peck

If you know that the roof is not leaking, then you know a lot more information about that roof than you are sharing with us ... which makes it a guessing game on our part.

If it was leaking of not, past or current, still leaves the same data to extrapolate information.
I knew as much about the Roof as you knew when I posted.

Originally Posted by Jerry Peck

That's almost like showing us a photo of a duck's bill, and a photo of webbed feet, then another photo showing a beaver's tail ... then asking us what kind of animal that is (yeah, I know what that animal is).

I showed the roof covering, the pattern of the blisters in measurable increments.
Humidity is always important to me. Appears the roof plenum was not venting correctly.
Lots of information there.

Originally Posted by Jerry Peck

When someone posts something, they are 'painting a picture' for the rest of us to 'see', and unless the picture is complete enough, all we 'see' is the 'white space' between the words ... you need enough words to paint a complete enough picture for us to 'see' it.

As to your, "When someone posts something they are 'painting a picture' for the rest of us to 'see'"
I understand. What most do and how I posted was intentional.
I left images. Little narrative.
The narrative left a questions of/for variables.
It was purposely done.
I personally try to think in broad strokes and extrapolate data by looking at all the information for the data gathered.
Not a check list by any means.

Sorry if it appeared to be unconventional.
I will try to do better.

Originally Posted by ROBERT YOUNG

r1c.JPG1r4.JPG

I suspect there is ten-test, modified rolled on top.

No signs of water infiltration.

Originally Posted by ROBERT YOUNG

Moisture.
Wet decks are prime suspects.
I will perform a cut test, but only at the owners request.

Dislodged and loose fitting plumb stacks.
I was hoping, or wishen as Jerry would say, for that reply.

Report about to be delivered.

no Cochlear dead regions test that i'm aware of
there is ir, nuclear & core of confirmed suspect areas

you say

No signs of water infiltration.

&

Moisture.
Wet decks are prime suspects.
I will perform a cut test, but only at the owners request.

which is it & are you a pro roofer that can successfully cut up their roof & make the necessary repairs that won't void any warranty between the owner, installer & mfr

maybe a bit out of your league on this 1 & need to find/work in conjunction with a pro roofer

unless

No signs of water infiltration.

is the evidence observed & this is nothing more than a cosmetic issue at this time

no info = no charge = no report

there is tuition for every life & business lesson

As Barry said - only a licensed roofing contractor should be cutting into a roof.

I have had several projects which required core sample cuts ... the core sample cuts were made by the roofing contractor I brought with me ... they were licensed and insured to make whatever cuts and repairs the owner authorized ... and all warranties were intact.

No way was "I" going to open up a roof and become responsible for it.

Originally Posted by BARRY ADAIR

no Cochlear dead regions test that i'm aware of
there is ir, nuclear & core of confirmed suspect areas

Thanks.

Originally Posted by BARRY ADAIR

you say &

which is it & are you a pro roofer that can successfully cut up their roof & make the necessary repairs that won't void any warranty between the owner, installer & mfr

Roofer b class, when they had classes, sense 1981.
Warranty is void by the installation.
An alturative would be to see if the roofer would extend their warranty.

Originally Posted by BARRY ADAIR

maybe a bit out of your league on this 1 & need to find/work in conjunction with a pro roofer

While some may agree, others may not.

Originally Posted by BARRY ADAIR

unless is the evidence observed & this is nothing more than a cosmetic issue at this time

no info = no charge = no report

there is tuition for every life & business lesson

My tuition is 40 years working around residential buildings.
I paid my dues IN FULL.
I have test measurement results from my Tramex MRH III.
The membrane is dry.
That does not circumvent water intrusion by installing flashing and coping metal improperly in my books.

I have asked for a retainer of xxxx for 20 hours work.
There are several moisture concerns.
As you mentioned, a qualified trades person is recommended to each suspect condition to pass on my liabilities.
As for my work ethic and diligence to insure questions are answered at arms length and recommendations issued are amicably presented, I am not worried.

Thank you Barry.

I own a commercial pressure washer. Have so for over 15 years.
Not worried about finding leaks when sealing them is what is required.
In 25 years I have located all but one point or cause of moisture intrusion.
The proper recommendations were made for all. I am not apart of what they do after that.

Originally Posted by Jerry Peck

As Barry said - only a licensed roofing contractor should be cutting into a roof.

I have had several projects which required core sample cuts ... the core sample cuts were made by the roofing contractor I brought with me ... they were licensed and insured to make whatever cuts and repairs the owner authorized ... and all warranties were intact.

No way was "I" going to open up a roof and become responsible for it.

I know everyone is looking out for my best interest.
Much thanks.
But lets us avoid the misguided intention to (ass/u/me).

A roofer will always be present with wavers signed.

"The road to hell is paved in gold with good intentions."
As a business man, In God we trust..."All others pay cash with a signed waver."

We learn through sharing.
Much thanks as always.

Robert,

This is what YOU said.

Originally Posted by ROBERT YOUNG

I will perform a cut test, but only at the owners request.

Nothing in there about having a roofer with you - "I will perform" ... do you recall what I said earlier about narrative and describing things?

*WE* are not making "ass/u/me" assumptions/presumptions ... no, WE are reading what YOU write.

With Jerry on the difference of " I will perform..." and " I will have a cut test performed...".
A little difference in the wording makes a big difference in the understanding.

Don't think Jerry is jumping on you Robert, just pointing out to others that before doing anything you first must be qualified with experience in a specific area as professional. Else defer to others.

Robert, please don't take this the wrong way. I'm not pointing fingers but just pointing out the

elephant in the room. We (correction "I" ) can't understand clearly many times.

I suspect this is due to the language differences.

I don't speak French and I suspect that French is your first language.

When you post messages it is like trying to read between the lines since you don't use

prepositions, modifiers, etc. in the traditional "American" English way and American spelling.

When you try to be concise/ brief such as with the post, it really gets hard to understand where

you are going.

Again, I'm not trying to be rude, just explaining some of the difficulty we face when trying to

communicate with the written word here.

Context greatly improves the ability to communicate and this post has very little context to give

hints as I try to understand.

Maybe this will help you to help us.

Originally Posted by Jim Luttrall

Robert, please don't take this the wrong way. I'm not pointing fingers but just pointing out the

elephant in the room. We (correction "I" ) can't understand clearly many times.

I suspect this is due to the language differences.

I don't speak French and I suspect that French is your first language.

When you post messages it is like trying to read between the lines since you don't use

prepositions, modifiers, etc. in the traditional "American" English way and American spelling.

When you try to be concise/ brief such as with the post, it really gets hard to understand where

you are going.

Again, I'm not trying to be rude, just explaining some of the difficulty we face when trying to

communicate with the written word here.

Context greatly improves the ability to communicate and this post has very little context to give

hints as I try to understand.

Maybe this will help you to help us.

Thank you.

Jim, I am a native English Canadian.
Parents, first generation Canadians.
Fathers, father from UK. Mothers, mother from Southern Europe.

I admit I am not trained nor educated in traditional "American" English way and American spelling. Nor do not speak French fluently. My comprehension of the French language very basic.

That being said. There are 32 dialects of the English Language around the world.
I was educated under many of these spoken English dialects by teaches from many countries. Most educated under United Kingdoms British educational system, National Curriculum.

I started working at 16. Twice trying to re-assimilate into the Canadian educational system without success.

Jim, we all learn differently.
IMO, the current North American educational system is injustice. I outperform this boxed in educational system continually.
I have earned the respect of large building firms advancing to recognized levels. I trouble shot instinctively, communicated well, remembered specifics without having to look up invoices, past data and insured projects moved along without incident.

I am not offended by your post. I do not understand why others compare others to others. Judge them by their individual qualities. Posts like that are meant to be privately sent.

Have a good day, Jim.
Best regards.
Robert

Robert,

The features shown in your roof photo are referred to in the roofing industry as 'ridging', or sometimes 'picture framing', not blisters. Blisters in a modified bitumen roof occur between plies, such as between the base sheet and cap sheet, and are usually the result of air pockets that expand over time. Blisters are usually pressurized. If you press down lightly on the ridges shown in your photo you will likely find that they flatten easily and are not pressurized.

When ridges form in a 4x8 pattern they are generally occurring over joints in the decking or possibly board insulation. The ridges generally form as a result of expansion and contraction of the decking due to changes in moisture content (changes in attic humidity), or repeated condensation on the underside of the membrane over the decking joints, causing the membrane to expand slightly.

A standard built-up roof membrane would begin to crack and wear through at the ridges in short order, but modified bitumen is more durable and can be expected to last much longer, even with the ridging.

I roof has good drainage, at least in the area shown, and appears to be in pretty good condition. If I were writing a report on this I would simply report that "some ridging of the membrane is observed, but the membrane appears serviceable at this time".

Edit***Having just seen the additional photos I notice one roof drain and no overflow drain. I also see trees close by that can result in tree litter on the roof. This is a definite problem condition, and one that should be reported.

Don Putnam
www.roofconsulting.com

Thanks Don.
I suspect atop the wood plank roof deck is ten-test.
Ten-test is/was typically used over plank decks in my neck of the woods.

I roofed many homes like this, mopped, and saturated ten-test, bitumen spray on organic mulch board, are used, and not plywood, as the substrate before mopping the dry sheet/ply.

I have ripped off/removed roofs were the roofer used unsaturated ten-test. Many brand names.
The organic mulch swells when wet and the roof under preforms.

Notice the sub deck is perpendicular wood planking above 4"x4"beams and posts.
(Typical wood framing for the circa,)
No nails or screw fastener penetrating the roof deck.
This leads me to think ten test organic mulch.
There is an image of the attic plenum.


Also, here is the narrative from my report.
Water was used to show "ridge blisters" and follow a downstream movement of the bulk water to the drain.
a. Water is dammed in-areas. Does it remain for up to 48 hours? weather condition many allow this.

Flat Roofing is to consist of a flat surface, be smooth, and slope in a downstream direction to a point of dispersal.
IE: Roof drain, side suppers, or gutters at or below the roof eave or the end of the roof.

Many buildings in this neighborhood are of the same circa. 1900 - 1940's.
Most are BUR roof systems on the semi detached multiplex, multi family buildings. Fourplexes.
They out perform modified and well as TPO.

Full parapet roof. The sides are 24" high. No scuppers.
The drain is the proper drain. The top accepts water is the sides block.


I mentioned to the home owner, "the roof will under preform but should last many years to come."
The roofer that installed the roof was notified in 2012.
Two reports have been completed by experts in 2012 before I arrived.
Both well known. One an architect highly recognized for over 40 years of defect recognition service in Montreal.
I asked the home owner, do not send the previous roof reports to me until I processed my assessment of/on condition. I wanted to start with a null hypothesis. Best to work from a blank sheet.

Hypothesis: Metal installation, coping size and the configuration/fabrication of the coping, appears to be one of the issues effecting the home allowing moisture intrusion in the roof and wall assemblies.

I was taken back by one experts report. He had his hand directly on the issue pulling the coping off the wall while another individual took the photo.
Water defies gravity. Capillary action.


Thanks Don!

Robert,

Tentest as you likely know is like a sponge when it becomes wet. Just my experience where its been used under EPDM roofing material (ethylene propylene diene terpolymer).

Best,

Originally Posted by Raymond Wand

Robert,

Tentest as you likely know is like a sponge when it becomes wet. Just my experience where its been used under EPDM roofing material (ethylene propylene diene terpolymer).

Ray, I concur.

Not many inspectors have the opportunity to observe what is behind the membrane. Fiber boards have been around a log time. Typically as an insulator and substrate.
Homasote®, Celotex®, Insulite, Nu-Wood, Upsonboard, & Similar Fiberboard & Insulating Sheathing Board & Plasterboard Products. Ten-Test was a brand name.

Installing commercial slope to the drain, dry wall was used atop the corrugated steel decking. Then sloped foam. Organic mulch board to finish as the substrate before the dry ply was fastened.
Atop, 5 or 6 full wet ply's, including stripping curbs and boxes 6 times.
Lastly fiber mesh to insure stripping cuts stay tight on the angles.

You are dizzy going around in circles stripping boxes six times.
6 x 4 = 24 strips of cut paper to meet the size of box for each vent box. Fiber mesh is wrapped around the box at the end to ensure all the cuts and mopped folds stay warped.

Better trust the mop man. He can easy mop your hand with 550 F tar.

I typically/usually see foam substrate with organic board in modified roofing.
Modified Bitumen Roofing Products, Modified Bitumen Materials, Modified Bitumen Roofing Product Sources, SuperKatepal modified bitumen shingles

Originally Posted by Jerry Peck

Robert,

This is what YOU said.



Nothing in there about having a roofer with you - "I will perform" ... do you recall what I said earlier about narrative and describing things?

*WE* are not making "ass/u/me" assumptions/presumptions ... no, WE are reading what YOU write.

I was mistaken in my narrative.