Flat roof_Built up or Duralast... Or something else?

Hi Guys,

I have a 14 year old house in Tucson Arizona with a flat roof, and it needs significant work done. It has a built up roof right now, and there is significant buckling visible. I have been having repeated problems with leaking along the inside edges of the exterior walls especially near Downspout areas for the life of the roof… Some of this may be related to the fact that the original roof was not installed properly (they ran the sheeting up the inside of the parapet, but did not bring it over the top before capping :roll: Great huh?) At first it leaked along the entire permitter of the house, but another company came out and did some sort of seal on it that took care of most of the problems… except at some of the downspouts which seem to need work about every year or 2.

I just got 2 quotes from the same company on repairing it. One for stripping it and redoing the built up roof, and the other for Duro-last. The difference in price is significant ($11,000 for built-up, and $26,000+ for Duro-last). At the time that the inspection was being done the person pushed pretty strong for the duro-last, basically saying that it would be pretty much maintenance free, cut down on my heating and cooling bills, and would solve all of my leaky roof woes.

I have nothing against a really great roof that has a warrantee, low maintenance, and better R factor, but Does Duro-last really deliver on that promise to the tune of an additional 16 grand?

Would a properly done Built up roof give me similar performance ? (I know that I would have to have the white coating redone every 2 years or so). All of the leaks in the past have been at the edges near the down spouts, we have never had a leak near the interior of the house, so I think that it is a pretty good roof as far as pooling and stuff like that.

What do you think?

Also, are there other roofing options that I should consider?

BTY, the exterior walls are Stabilized Adobe construction if that makes a difference.


durolast does not warrant residential roofs.

look into spray polyurethane foam as another option.

Hi Aaron,

Thank you for your information. the person who did my estimate, actually told me that it comes with a 15 year warrantee on materials and 5 years on workmanship. I will have to ask them about that… Perhaps the warrantee is only from their company, and not Duro-last.

BTY, I was just about to log on and add a question about SPF when I saw your reply. I just ran across an article on it (unfortunately only a very short one) and it looked very interesting.

Is it true it can be applyed over the existing roof, and any future work is just applyed over that without any tear down? is it as low maintenance as they say?

Very roughly, what sort of price range does it usually come in at? Is it closer to the Built up or the single ply prices?

On my estimate for the Duro-last, they included elevating the sky lights and a few other things and adding special flashings. is something like that necessary with SPF? I’m kind of worried about idea of messing with skylights and other things that Have not leaked for all these years.

High UV, Heat and 40+ degree day to night temperature swings ( including some freezing at night during the winter) are problems in this area. Does the Spray polyurethane foam do well under these conditions?

How would I go about finding someone in my area who is reputable and deals with this method of roofing.


Edit I found one article that said that the costs for SPF were about 20% higher than “Traditional materials”. I assume that by Traditional materials, they are talking about Built up roofs. Does that 20% sound about right?

It also sounded like the primary maintenance for SPF was Reflective coating ~ every 2 years. is that about it, or are there other maintenance issues?

I think I’d find me another roofing company or two to give you bids. As for the Durolast roof, like Aaron said you likely won’t get a manufacturer’s warranty, and I seriously doubt it will save you anywhere near $16,000 over the course of its life.

As for the SPF, the contractor needs to know what they are doing when they install it. Most of the SPF failures are related to either poor installation, or poor maintenance. Personally, I’d remove the existing roof, install polyisocyanurate insulation, and a built-up roof membrane with a modified bitumen cap sheet. But hey, that’s just me!

For a no BS residential Labor and material warranty and all the benefits of cool roofing with a sustainable system you need Hydro-Stops Premium Coat system. It is less expensive than Duralast and has a better track record. Thier reps will even babysit the job while it is being installed so you dont worry.
www.hydro-stop.com .

IF you dont want to roof again it is the way to go. SPF isnt worth beans unless it has a good acrylic on it and they (typical spf installers) usually only use crap acrylics to coat it. Thats why it only lasts 2 years. A quality acrylic will last 10-15 years.

You will get about 10 -15 years out of a really good BUR in your region but then you will need to do it again. A really good BUR will probably be more expensive than you have already been quoted and If they really wanted to make sure you had the best, they would recommend you coat that also.

Hydro Stops system doesnt require the other systems at all. It works all by it self.

Hope that helps.

I used that Hydro-Stop out here. It works great. alot longer than any other ive tried.

Geez I didnt mean to sound like a Hydro stop commercial. At least Cowboy knows what im talking about. :wink:

Hi Cerberus,

LOL, after seeing the bottom line on the 2 quotes, and the huge gap, I figured that additional quotes would be in order, but I also thought that It was a good idea to become a bit more informed first . The information on the BUR and the Bitumen cap sheet sounds interesting, and I will do some more reading on it. Is that what is sometimes called a ‘Hybred roof’?

Thanks for the Warning on the SPF, I had read in one articucle that the skill used in it’s application was a significant factor I will keep that in mind.

Hi samskii,

Hydro-stops sounds interesting. I checked out the link you provided (Thanks) and I have a question; Do they have to remove the Old BUR roof before applying the Hydro-stops, or can it be applyed over the top of the old roof? (the old one has White Cool coat, not gravel on top). Do you have an idea of approximately how much more it costs for Hydro-stops verses BUR?

BTY, The Quote for the BUR roof from the first company does include two coats of reflective coating, but it is the type that needs re-applyed every 2 years or so. :frowning:

Just a quick question about SPF roofs for anyone: What do you think of SPF if it is properly installed and has a decent Acrylic coating? BTY, what brands do you consider Decent Acrylics? Is it necessary to remove the BUR roof before applying a SPF roof… the literature I have found so far is not clear.

Hi Cowboy, Thanks for the input. ;p


LOL samskii, Not a problem. it is nice to know that a person truly believes in a product they use or recommend. . :slight_smile:


Before ANY of these ssystems go down, the contractor must determine the suitability. We cannot say, because we have not inspected the roof.

Cerberus is dead on about the SPF. YOU NEED TO KNOW WHAT YOURE DOING TO DO IT WELL.

Sam is almost dead on, but he left out the part on Hydrostop that says…the DFT will determine the life of the coating. 2 years, even with an acrylic, any acrylic, will be about a half gallon per square (in theory because I do not think you could put it down that thin). A fifteen year maximum with an acrylic coating would be at 4 gallons per square, yielding a 32-36 mil dry film thickness, plus a considerable amout of flashing and detail reinforcement work. I used to a bit of Topcoat and Mulehide acrylic, and stopped when they proved inadequate for long term waterproofing, but thats just me.

SPF, properly applied, will be your best long-term value because of its ease of mainteneace, air stop qualities, monolithic insulating of aged R 6 per inch (this system can pay itself back in terms of energy savings. Couple that with a white Hydrostop acrylic on top, and the savings compond in shorter order.

If you want the benefits of SPF, and the least maintenance possible, I would go with a 3" 3# foam with a 60 mil polyurea membrane over it. This will give you a harder topcoat, which helpd to stave off critter damage, mechanical damage, and to some degree, hail damage. FOR THE CUSTOMER LOOKING FOR LONG TERM ROOFING VALUE, I RECOMMEND THIS SYSTEM. ABOUT 4-5 BUCKS A FOOT. 20 year life expectancy before re-coat (3 bucks a foot at todays prices for another 20 year expectnacy)

nothin left but table scraps.


Hydro Stop is not designed as a coating, so having said that …it is not to be compared with the likes of Top Coat, Mulehide, Kool Seal, and the like. Hydro stops premium coat system is a “system” Meaning there are no variables in the DFT when it is complete. It is more like a fluid applied single ply. The DFT of the 10 year Premium coat system is 45mils or (4 gal per sq). 15 year 60 mils( 5.5 gps) 20 year 80 mils and 2 plys. (7gps) and the system is fully reinforced… every time. Unlike the “seal the laps and penetrations and spray the roof” products . The manufacturer is very strict about how the system is applied and they will have a rep on site once per week during application to enforce the application specifications.
These things all matter significantly, and make my clients more comfortable and my job easier and more of my projects successful for a longer period of time.

As Aaron said the existing substrate would need to be evaluated before determining whether or not you could apply the system over the top but about 90 % of the time the manufacturer will give the nod to go ahead and cover it. The Hydro Stop system will cost about 275-400 dollars per square depending on site conditions and wether or not tearoff is necessary. NDL warranty is included in that range.

Utah, Wyoming, Idaho, Nevada. Buildings are big and competition is spreadout. Just the way I like it. Use that stuff to seal my seams and internal gutters on my maintenance contracts. I like it fine. I have buildings 12 years plus with that on it and havent had to recoat yet.

When all is saidd and done, no acrylic can pay for itself…they just can’t

The higher the fuel prices, the bigger the savings…its that simple.

Huh? Uhhhhh… So lets break it down.

In the area where cactuskim lives the weather can stay above 110 degrees for a week at a time sometimes reaching a 115 and then cool all the way down to 105. At night it might get all the way down to 90. This is the pattern for much of July, August and September. The Air conditioners may not turn off for months.

Acrylic - cool roofs have been proven to save energy up to 1/3 $$] on average and actually allow the ac’s to cycle in the dead of summer. The Cool Roof is just above ambient air temp as compared to a 200 plus degree aluminum coated or granulated modified or metal roof.

Utility companies are now offering rebates up to 1 dollar$] per square foot for a proven cool roof system in CA, AZ, NV and other states.

Sustainable roof systems cost about 1/3 $$] of the initial system installation when the warranty is up. If the warranty is in place and the roof wears sooner than the anticipated life , the manufacturer will redo it for free.$$$$]

Under certain circumstances you can expense the whole cost of the NEW ROOF as a maintenance and therfor get a 100% tax deduction the very same year you did the improvement to you property. $$$$$$$$$$$]

How can you not consider this route for all of your flat roofs?
Just at the very least… consider it!

It absolutely does Pay for itself… maybe even put money back in your pocket.

I as a professional in my field have hundreds and hundreds of roofs with this system on them and all are performing very well in all types of weather and climates. I am offering data and my experience to these forums just to broaden the field of roofing excellence in the industry beyond the dead dinosaur juice roofing products.

Now im going to go play hot wheels with my kids and eat cookies!

umm, if you are selling a new roof, it must be ammortized over 39 years.

how do acrylics stand uo to foot traffic? what are your shore test numbers?

acrylics are great for reflectance…just dont tout that garbage as waterproofing…otherwise your product’s warranty would not be exscluding areas of water on the roof. polyurea would not exclude water on the roof…it is a true vapor barrier.

your stuff dissolves after cure with constant contact with water. dude, its just an inferior propduct for waterproofing. i do like it for reflectance, though.

Sounds like you could use a new tax guy.

FM 4470 Class 1 roof systems approval. Meaning it is subjected to the same testing as any other roof. It passed. Class A fire rating, 1- 90 to 1-735 uplift depending on substrate. Foot Traffic (see Below) Passed , HAIL damage, class 1 SH, and leakage under pressure PASS.

A 9% reduction (wear) in 1500 cycles- a cycle consists of a metal plate 3" square being pushed down on to the system and pressurized to 200 lbs. and then to 0, and repeating.

I dont know What the Shore A test results are. But ill find out.

And to make it clear. Its not my product. And warranties are negotiable. They use their stuff to coat water tanks for crying out loud, thats why they have an NSF rating.

Barrierguard has a comp strength of 5600 psi and is a non skid waterproofing which could be put on a parking structure or a deck for about .70 cents a sq ft. :smiley:

Oh and Dude… HS products may or may not be as superior as Polyurea but It doesnt take a 20 k investment in equipment to install it, which makes it more accessible.

I have waterproofed entire building envelopes with this “garbage” with nothing more than a few helpers, a pair of scissors, some brushes and a drill mixer.

I have also pumped 3 feet of water out excavated foundations , and waterproofed it the same day, backfilling the next day. Nobody could do that if it dissolved. In fact I couldnt do that with anything else but this.

I cant say i have ever seen a residential NDL warranty from a polyurea, that is what we were talking about.

ding ding …gladiators ready!!!

OK, but I can do the polyurea at the same prices I can do a full system acrylic for…about 3 bucks a foot, and yield a membrane that is nearly twice as thick, ten times harder and just a flexible, that will not dissolve (like the samples I made from your bucket of stuff did in water…It turns to milky water.)

Youre right, you do need a whole bunch of technical coatings, primer, surface prep, mechanical knowledge, roofing skill, and the expensive equipment to do my system, but that is another reason I like it…not any joe blow can put it on…but if thats what I need in order to offer such a superior product, then I’m game.

Are you a hydrostop dealer?