Spray Foam Roof Coating - Advice

firemike

Hi Everyone!

I have a question for the commercial roofers and possibly HVAC guys, I am trying to get the best possible solution for one of my good commercial clients. Sorry for the lengthy post, but I want to give you as much info as possible for you to give an informed opinion.

Here is the situation:

My client - a small bar/restaurant business, occupies a building with masonry walls and a flat (yeah - I know!!! ) wood framed built-up roof (black), typical 1950's strip style commercial building. The roof falls approximately 1 foot in the 80 foot length towards the rear of building, parapet walls on the front and both sides.

Inside, the ceiling is drywalled almost everywhere , the attic space varies from 24" at the front of the building to 12" at the back, so no room to work in up there.

There is no insulation in the attic area, none! Through the inspection holes I made you can look up and see the 2x12 framing and the bottom of the wood roof decking. During the summer, the roof gets so hot you can hardly walk on it, on a sunny day the attic space has got to be 140 degrees plus, and you can feel the radiant heat coming from the ceiling drywall inside.

There is a 10 ton HVAC rooftop unit for the dining area, but it can't keep up with the load. On hot summer days it barely cools the dining area to down to 80-85 degrees or so. His AC guy talked him into adding a split AC unit last year, which he did. They installed a 4 ton unit, but it barely helped, so they are talking about installing 2 more 4 ton units this year.

My thoughts:

I think they are wasting good money installing all these new units at $4600 each, plus the electricity to run them. My idea is to install either a white membrane roof or a spray-on foam coating to the roof. The roof is getting towards needing repair/replacement soon anyway.

The plumbing shop 3 doors down has a white membrane roof and they cool their shop, which is roughly the same size, with a much smaller AC unit. Granted they don’t have the people/equipment load the bar does, but the have roughly the same cubic feet.

Another thought I had would be venting the attic space as well, possibly with power vents and fresh air intakes, as there is no active or even passive venting of any kind other than incidental air leaks for the entire attic space.

What are your thoughts? I think the HVAC guy is going the wrong way by adding more cooling instead of taking away the heat load. Thanks in advance for an information or opinions.

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-Mike-

AaronB.

Well, the HVAC guy is doing his job by selling them his products.

I think you are on the right track with the SPF. At nearly r-7 per inch, it is the best commercially available insulation. Too bad the drywall couldnt come down allowing you to have the foam installed on the interior...then you would never have to coat it.

It may not work very well on the roof due to the fact that you have a cold roof assembly. I would want to see the sides of the attic space covered as well to ensure a contiguous building envelope.

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thom

If it's time to re-roof anyway, do a complete tear off, cut holes in the decking, insulate the attic through the holes, patch the holes then re-roof.

I've done this a few times with blow-in insulation in old flat roof houses and it works just fine. You could do a foam-in in the cavities but that would require more holes.

Just have the insulator out there working while the tear off is being done.

When the roof is re-done, use a reflective coating instead of gravel. There are some that reflect more than the gravel and that will help also. You can get the replacement coating job every 5 years.

Wolverine-Eric

I can give you help in regards to polymer roofing. If you use spray foam you are going to need special equipment for that. You typically need a plural component spray rig $$$$$.

From the sounds of the expenditures, I think what you need is an Elastomeric Acrylic (>300%) roof coating that is Energy Star Compliant. This will reflect a great deal of the heat. Of course, insulation is going to make a HUGE difference!

You customer should consider that installing more units are going to increase their operation costs above and beyond the initial cost (not to mention it will create air pollution).

I am familiar with several manufacturers (we don't make it or sell it) of these roof coatings. Some are WAY better than others. Leave a post here and PM me if you want a recommendation. I don't check all of the forums in here... OR... start a post in the paintalk forums... I usually read all of those...

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roofsmart

I have a recovery system that is perfect for your situation . It is a plural component system. It is a spray applied fully adhered system which can go over almost any type of flat or metal roofs. Then it is top coated to reflect ultra violet rays by 87%.It usually reduces inside building temperatures by 20 degrees and roof temperatures by 70 degrees.

AaronB.

wow, lots of plural guys all of a sudden....

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http://www.roseroofing.net/
Seamless Industrial and Commercial Roofing Systems, Residential Repair. For Those That Demand Quality!
Free roof inspections within 12 miles of our locale.

AaronB.

87%? Is that a white aliphatic?

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http://www.roseroofing.net/
Seamless Industrial and Commercial Roofing Systems, Residential Repair. For Those That Demand Quality!
Free roof inspections within 12 miles of our locale.

roofsmart

No its a silver polyglycol

AaronB.

tell me more about polyglycols.

i AM DOING POLYUREA AND LOVE TO LEARN AS MUCH AS POSSIBLE.

Darned caps lock is too close to shift.

__________________
http://www.roseroofing.net/
Seamless Industrial and Commercial Roofing Systems, Residential Repair. For Those That Demand Quality!
Free roof inspections within 12 miles of our locale.

firemike

Roofsmart:

I am interested in what you might be able to do, but you have no contact info listed anywhere. PM me or email me at:

mharden@falconcontracting.biz

Thanks!

Mike

__________________
-Mike-

theflynner

1) From 20-years of experience, I think think the Spray-urathane roofing is the worst system in the market. I always recommend removing the existing roofing, If you don't you will be trapping moisture and mold. -- Mold thrives in dark, warm and moist areas. This will help the sale.

2.) Looking at the whole situation, another option would be to add enough insulation above the wood deck to separate the exterior heat of the roof from the interior. ( Also provide slope with tapered insulation). In the winter, you are separating the cold of the outside from the warmth of the interior. It is the same principle. This way you don't have to deal with any interior work.

Flynn in MN

dfw_lr

Well, not quite the best. There is a radiant barrier bubble insualtion that is a certified R 14.5 for 5/16" thickness. It's both a vapor and moisture barrier and a radiant barrier, reflecting 97% of the radiant heat entering your attic. This is about 20% better than your radiant paints. It can be stapled under the roof decking or fit into the cavity. If you consider the R Value per dimentional thickness, this stuff out performs aviation grade foam. If you don't believe me, e-mail or call the company and ask for the specs. Google "radiant barrier" or "Tempshield bubble". Some companies that have it are Reflectix Inc., Innovative Insulation Inc., Radiant Guard, and Eagle Shield.

nano roof

My thoughts......................

Have you looked into G.R.E.E.N. (Green Rated Energy Efficiant Nanoroof) this product will reduce the building envelope temp to within 5 degrees of ambiant temp and in most cases be equal to R19-R24 insulation, also causing the HVAC system to run 30-55 % less.. ie: smaller units. This product is Cerimac Epoxy roof coating that will extend the life of the roof 15 to 20 years without tear-off or replacement. energy4days513@yahoo.com

johnk

Your not tryin to push the nano roof at all are you?Nano,nano

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