Is there a flat roof expert in the house?

My condo was built in 1981 and needs a new roof. I live in Nevada where the tempature can have a range of 50 degrees and gets hot in the summer and some snow in winter.
My thoughts are seams are the achilles heal of a flat roof and I realise that the install is very important.

So far I have contacted 2 roofing companies. One specialises in flat roofs and sells the SPF Dow Corning system. I like everything I read about this roof. The 2nd company installs modified bitemum and EPDM roofs and also torchdown. These roofs all have seams which makes me just a little nervous.

I expect to pay about 10k for a 20 year roof, the size is 32X60ft.

Some questions I have are what kind of warranty should be offered by the roofer himself excluding the manufacturer warranty.
If I go with a SPF roof should a tear down be done, the present roof is a membrane with gravel and a large patch over the original.
Do any of these roofs handle expansion of the substructure better.
For the SPF would you insist on a hybrid poly coating.

Any opinions based on actual expience would be appreciated.


This would be Aaron B territory.


All of those systems are proven over the years.

SPF or Edpm or Asphalt will hold up or fail depending on the installer not the material used.

They all need mateince.

Tearing off is always the prefered method.

There is no way to give a price without actually being on the roof. There are so many factors that go into a price. If someone gives you a price it can be very misleading. If someone insists on a price before we can do an inspection, we tell them to find someone else.

ill agree with that. god if that does not happen atleast once a week.

All of the systems mentioned are good systems, but as you know, as long as the installer knows his dooky.

LEfty is right on all points.

If you go with the SPF, I would absolutely recommend a hybrid polyurea over acrylics coatings anyday, especially if you would like to obtain a long service life before re-coating.

At today’s pricing, if the substrate was solid, with no wet insulation, or rotting substrrate, and we could go right over, you would be around 11,000 for 1" of foam, and 48 mil hybrid polyurea topcoat.

Remember, there are many variables that go into it, but properly mainatained, a foam roof can last indefinitely. Also, one inch will add R7 to a proper configuration.

Hope this helps.

There are a few of us here!

Personally, I would shy away from the EPDM roof if I was you. It is the most unforgiving roof of the three, and the contractor has to take greater care during installation. If I was putting on an EPDM roof myself, I’d have no problem with it, but I’ve seen too many poorly installed EPDM roofs to just trust anyone installing it.

As for the SPF vs. the mod. bit., everyone here knows that I am not a fan of SPF and will recommend an APP mod. bit. every time. As time goes by and SPF starts getting a long-term track record of successful installations without inherent problems to the system I may change my tune, but for now the APP mod. bit. system has a longer track record for success and is what I would recommend. With that said, you would probably like the reflective and insulating qualities of the SPF, though you can get the R-value you need with polyisocyanurate insulation installed beneath the mod. bit. roof also. If cost is an issue, the SPF should also be cheaper than a good multi-ply mod. bit. roof.

I really appreciate all your helpful responses!

A few questions :

2 Years ago we recieved heavy snow 4 ft on my roof it held up ok .
Would SPF hold up the same?
I have problems with water ponding as the exsisting BUR roof is not completely level or when applied was not condusive to good drainage
flow.It ponds at the right rear area where it leaked last year ruining the MBR cieling and outside wall.
There is a history of leaks and water damage with this roof 25+ years old.

The SPF roof should alleviate this problem if applied correctly , right?

Should I be concerned about the SPF thickness 1" or should I get a bid for
1 1/2" ?

The ModBit roof Quote I recieved specs 1 layer with aluminum coating
with new waste pipe flashing,1 layer of glass base sheet,new cant strip to all wall & curb turn ups,1 layer MBM to roof edges and transitions,tear off of existing roof to sheathing,clean up,12yr warranty for 11,000.

2 layer ModBit With same specs above for 16,000. 20YR warranty

This is a torch down application.
3 yr warranty for the roof installer.Relies on the Mfg for balance of term.

Cerb how’s that sound to You?


Here is a picture of my condo roof. My part of the building is on the north side or top of the picture. There are 2 units per building.

I hope you can gleen some info but I am unsure if so.



First of all, don’t get too caught up with the manufacturer’s warranties as most of them are not worth the paper they are written on. That is not to say the manufacturer won’t stand behind their product, but in general the warranty is against manufacturer’s defect and does not protect you against damage by others, nature, etc. Also, to keep a manufacturer’s warranty in affect you have to have periodic inspections performed on the roof, usually a quarterly inspection or some sort of maintenance program.

As for the mod bit roof, I would prefer a base of polyisocyanurate insulation overlaid with perlite or woodfiber board. Mop a base sheet to the insulation, and 2-3 plies of Type IV fiberglass felts. Overtop the built-up roof membrane you can then either torch-apply a granule-surfaced APP mod. bit. roof membrane or cold-apply the membrane with adhesives and torch the laps. Problem is, this system might be too costly for you. Also, you will want to have the roofing contractor install tapered insulation if needed to promote good drainage.

The 2-ply mod. bit. roofs aren’t bad, but my preference is to install a mod. bit. cap sheet over a built-up roof membrane. I wouldn’t really recommend the single-ply mod. bit., as one seam failure equates to a roof leak even though it can be easily repaired. The main problem with leaks is the roof board insulation becomes wet and loses its R-value, not to mention the entrapped moisture will cause the roof to blister and fail prematurely. Also, if I were to go with a single-ply of mod. bit. I’d prefer the granule-surfaced over the smooth-surfaced membrane.

Depending on you pocket book, you may want to consider the SPF if you are weighing it against a single-ply mod. bit. I won’t recommend the SPF, but it has been pointed out that I’m biased against SPF. Therefore, if you want to go that route I suggest you ask Aaron about them since he installs them and likes the system.

Thanks Cerb for the feedback.

Aaron any improvements to this description.

As for the SPF How does this sound.

Removal of gravel or existing roof layers. Dependent upon the integrity of the existing roof surface, dry rot or the amount of existing roof layers these may be removed as well as gravel. All blisters or penetrations will be addressed during the preparation.

Bonderized metal foam stop (perimeter flashing) to ensure a permanent roof system. This bonderized metal has been etched with materials that will not degrade and do not require primer when painted.

All drains or scuppers are removed and replaced new. Downspouts may need to be replaced at additional cost. Ask your estimator to give you a free evaluation of your downspouts.

Breather vents may be used to allow gases to escape. (Used especially when other roof layers exist.)

UV activated primer on the prepared roof surface. This is a lightly sprayed, black, acrylic paint which absorbs additional dust & debris as well as moisture.


SOunds just fine, except standing water CAN be eliminated, especially with SPF.

I like polyurea topcoat for its’ toughness vs. birds and HVAC servicemen.

I would also INSIST that the wet underlying be removed, not just “may” be removed.

If it is a good copmpany that has been around a while, then that is a good warranty. If the company may not be there next year, the warranty is useless. Get a mfg. system warranty built into your contract, so that if he goes belly up, your roof will still be warranted, and you will still be covered.

im with cerb,
lets not confuse AaronB bein the spray foam/coating specalist here , with bein the sites flat roof department.

mr/mrs fast996,
the one thing that almost allways gets ya a good roof is usin someone that has been in your town roofin all his/her life, at least close to 20 years.

they just hve a better chance of knowin what works and what dont.


Thanks Aaron,

I just talked to the roofing contractor. These are the items he mentioned.
They have been in business for 30+ plus years and family owned. They have the best people in the world. Maybe just a little spin there hey.

They offer a 15 year materials and labor warranty.

The materials are BASF foam and United coating their warranty is through the contractor only.

The quote is 2500 sf@7.00, a little more than anticipated. He told me I could get a $5.00 a ft qoute but I would probably only get a 10 year roof warranty and there may be corners cut elsewhere. After the 10 years it would cost me the extra $2.00 for recoating so in his words this is a game that sometimes is played.

The manufacturers warranty is usually for commercial jobs that are 10,000 sq ft or larger and probably would be a 20 year offered.

What do you think.

Ummm…I know that if any roofing company told me they were willing to do a cheaper job, but would cut corners, I would tell them to get the H___ out of here.

Theyre telling you right there that they are going to intentionally do less of a job?

Find another.

What I do know is that for $5.00 a foot, I could usually offer 1.5" of foam, a protective UV inhibitor, and a 15 year warranty.

Future recoat price is right in line with me.

Gweedo, dont start actin like you kow anything about roofing now LOL

Go look at my website, it shows what we do…you just have to look. Been commercial roofing 16 years, dude. Not as long as Grandpa Gweedo, but I’m gaining on him. :slight_smile:

Thans Aaron, you misunderstand me, this contractor did not offer to drop his price or cut corners. His bid is at $7 is that within reason or should I go shopping?


OK I get it. I am sorry. He meant from another contractor…

Anyhoo, It depends on the details, and geography. I have no idea his regional costs or labor rates.

I also do not know the amount of metal detail that has to go into it, or the tyoe of coating. If that is for the foam roof and a polyurea membrane, then go for it. Thats a good freakin roof.

It never hurts to shop around.

Find out what the mod. bit. roof will cost you per square foot, and what kind of insulation that includes. Then compare your total replacement costs for both roofs, lilke the SPF system I doubt you will get a manufacturer’s warranty of a residence but you should check, R-value for both systems, etc. Do your homework, and then make a wise and informed decision so you don’t have buyers remorse one way or the other.

Aaron will push you towards the SPF systems, and I will nudge you toward the mod. bit. Therefore, you need to make the decision on all the information you can acquire from this site, your local roofing contractors, and your budget. It is also wise to consider how long you plan on living in the residence before deciding how much of an investment you wish to make in the roof.

Aaron the coating is United Diathon. The United site says it is 100 pct Acrylic, any good?


Cerberus, I do more than SPF. Go look at my site already. I LOVE MOD BIT, I LOVE BUR, I LOVE EPDM. I have said this countless times. SPF, if properly applied is the only sustainable seamless insulated roofing system with the lowest long term life cycle cost, which actually comes back to you many times in the way of thermal efficiencies.

Your long-term roofing costs are greatly diminished compared to other membrane systems. Period. It has to be applied properly, and maintained, like any roofing system.

As a UV barrier, acrylics are awesome, but I can do polyurea for the same price, most times, and acheive a primary waterproofing membrane over the top of the foam also.

I know you do other types of roof systems, I just stated that you would push SPF’s where I would not. It is just a matter of preference, and I thought it was fair to let the homeowner know that not everyone is a fan on any one system.