Flat Roof Question

dhaselhorst

We are a property management co. We have two proposals to replace a flat roof. One calls for GAF Ruberoid smooth modified bitumen torch applied system with the addition of one coat of fibered aluminum roof coating at $2457.

The second calls for Firestone 180 modified bitumen rubber roof (torch applied) at $3250.

Are these products the same? Why would the first quote the additional fibered coating and be cheaper?

Both proposals include similar flashing, drip edge, gravel stops, etc.

We want the best value, not simply the lowest price. Is there a significant difference to the two materials to warrent the increase??

-Darin

red_cedar

Why don't you get your questions answered from the ones submitting the bids.

dhaselhorst

I have asked them questions, but often get answers like, Oh yea, Firestone, you have heard of that name, that's really good stuff. Or they look at me like they are explaining roofing for the 1,000th time to their 5 year old. Or say something like we only use really good materials, when I know there are different grades of materials, thicknesses, warranties, etc.

Additionally, when I ask one contractor about options offered by another contractor he often tells me how the other guy is doing it wrong, he must be offering something different, etc. Its very hard when looking for work in a new area (i.e. flat roofs) what the specific pluses and minuses are on a job.

While we have experience with traditional singles, flat roofs are new and I was looking for some outside opinions to help make the decision.

We rarely go with just the lowest price and try to find value in our purchase, paying for the options that make sense and maintain the property longer.

talos4

Rule #1 of a good contractor... Don't knock the competition in front of the customer. Doesn't make me look better, just petty and desperate for work.

The products are comparable. The Firestone 180 is a Modified bitumen, not Rubber.

Firestone is a better EPDM (rubber) manufacturer than mod bit.

Several factors could cause the difference.

Contractor "A" could have lower overhead and has a lower Gross profit margin on the job than "B.

"A" could be desperate for work and is pricing accordingly.

Need more info: How big is the job? Sqft?

Is it a tear off, or is it going over the top of what's there?

AaronB.

Dont forget the ever present "We dont need stinking insurance" line...LOL J/K

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dhaselhorst

Thanks for the reply!

Interesting comment on the Firestone. The bid reads ,"Firestone 180 modified bitumen rubber roof." If I understand your comments correctly, both products are modified bitumen, which is not rubber and not EPDM.

As far as the roof, its a tear off of asphalt rolled roofing, torched at the seams. The bonding near the gutter has failed and you can pick up the first section of the rolled roofing. I could probably have it all off in 1/2 an hour. Flat roof is on a rear shed dormer, front of building is shingled with 2 gable dormers. Roof is approx 6 years old, shingles are fine, flat rolled roofing has failed. Flat roof is approx 35 X 16. Both bids include fiberglass base sheet and new galvanized drip edge and gravel stop flashing.

What is the benefit of the fibered aluminum roof coating with the GAF? I thought coatings were a maintenance item after the roof was several years old. Would both products need the coating at install time? Only the GAF bid has it included. Or is the coating a benefit for durability and heat reflection?

Just trying to get the lower maintenance product at a reasonable price. Both contractors have workman's comp and offer warranties. The cheaper offers a 5 year warranty on workmanship the more expensive offers 1 year.

Sounds like the better deal is the GAF, if the products are similar.

Thanks for the insight.

roofwiz74

I would venture to say that the gaf is being coated cause it's smooth surface and the firestone is granulated.gotta protect the asphalt with something to block uv's.
I would go with the firestone product anyday.

not sure about gaf's products but most require a few months of weathering for oils to bleed out before they can be coated.

price diff might also be left over materials from another job.

gaf is a better shingle manufacturer than mod bit.

talos4

Throw that estimate away and get another one. Seriously,

A roofing contractor that makes that makes that kind of statement is NOT a flat roofer. "220-221 whatever it takes"

GAF recommends that everything gets a coating. If they could get away with it, they'd coat their shingles too!

My recommendation for a material for the job is a bit biased because we like the following products:

In order

Performance Roofing Systems, Derbigum GP. OR Derbicolor GP. Derbicolor is granulated with a color choice of 5 colors.

Performance recommends their products NOT be coated. Available 10 yr material warranty at no cost.

Johns Manville, Dynalastic 180 or 250. Good product, decent pricing.

Of the two we install far more Derbigum than anything else. Why? Track record. Outstanding performance.

Currently, I service several buildings with Derbigum roofs in excess of 20 yrs. with annual maintenance, these roofs are performing just fine. We are just now offering budget projections for one owner over the next 1-3 years.

Ask the contractors for either of the two products. I will tell you that not everyone can install Derbigum. It is not available in the local roofing supply house. Only factory qualified contractors can purchase and install their products.

Like I said above I'm a little biased

roofwiz74

i agree manville(schuller) are good products.

BULLHART

IMO whomever created the name "RUBBEROID" should be found and beaten severely. Explaining to customers that their roof is not rubber...well thats just hours of my life that I'll never get back.

red_cedar

isnt there an SBS product that can be applied either cold or mop or even torch. SBS is more rubber like then APP. Maybe they dont make it any more.

Specialist

I'm with Talos.
Roofwhiz is old school - JM hasn't been "Schuller" for 10 years.

If the roofer can't explain themselves well -- do you really want them using a 2,000 degree torch on your roofs?

River Rat Dad

To answer Red Cedar, Tamko makes a line of SBS called AWA. They have versions that can be applied all 3 ways.

roofwiz74

lol...yeah still weird for me to call it manville.

Grumpy

The rubberoid system is a smooth modified bitumen system. The firestone 180 is a granulated system. Granulated does cost a little bit more and IMO requeires less maintenance. When silvercoating a brand new modified bitumen roof the silvercoat wont last more than a few years. I prefer to allow the roof to age about 3 months so some nautral oils can leach out and the sanded surface can wash away. The sand is used to prevent the liquid bitumen from sticking to the machines during the manufacturing process. Once this has washed away the silvercoat will stick much longer.

Personally I dislike the rubberoid material but I know alot of guys who swear by it. I have been installing firestone for years and I would say both make comprable products, but youa re comparing an apple to an orange because you are comparing a smooth system to a granulated system.

What are the warranties (manufacturer and roofer) for each system? Who has the most expeirence with flat roofs(not all roofs are the same and being the best shingler doesn't quallify someone to install a flat roof)?


BTW neither product is actually rubber. It irks me when I hear people calling these products "rubber". However it's what most so called roofers call it. EPDM=Rubber. Most torch applied modified bitumen systems (APP) are modified with plasticizers, while some cold process applied modified bitumen roof systems (SBS) are modified with Butyl (a type of rubber), which is where modified bitumen got the term "Rubber"... But it's not rubber at all. It's bitumen that has been modified with some kind of plastic or rubber.

talos4

"It's black, smooth and on the roof must be rubber!"

A quote from an HVAC contractor who needed new Tall cones installed.

I looked at the job,

SBUR.

btw, he glued two witch hats to the roof b4 we arrived.