Green roofing options

[thomop]

Hi guys. Here in Australia we havent realy adopted the same green roof ideas that the US seem to be doing. I have noticed that many companys are painting roofs white, which has been endorsed by the goverment. Is this correct?

If so, does does the carbon offset or energy saving really make enough of a difference to warrant the inittial costing of the roof paint?

There have been a few programs here that have tried to get off the ground by lacked incentive for the government to back the ideas.

Any thoughts?

[Scottpat]

My experience has been that most energy saving ideas cost more than they really save the homeowner. They also have a tendency to cause additional problems that were never thought about until they rear their ugly head!

Once the government money is taken out of the equation those "Green" ideas tend to become brown and fade into the sunset!

[inspector57]

Choosing better during initial construction or normal replacement makes sense since it rarely cost much extra but to apply a "green" retrofit is usually "penny wise and pound foolish".

There are lots of new ideas floating around but you likely are seeing the stories only because it is new and news worthy, not because it is regularly being installed.

[guynextdoor]

I saw a similar thing happening many years back, every one was painting their roofs white. It was supposed to keep the homes cool in summer. Tons of "cool" white paint were sold that year and many thousand labor hours spent in applying this white paint. The savings in energy bills weren't significant enough to offset the cost of paint and labor. The trend has died a natural death.

[hausdok]

I saw a similar thing happening many years back, every one was painting their roofs white. It was supposed to keep the homes cool in summer. Tons of "cool" white paint were sold that year and many thousand labor hours spent in applying this white paint. The savings in energy bills weren't significant enough to offset the cost of paint and labor. The trend has died a natural death.

Not sure I agree with that. Some years ago I got a call from my mother who lives in Florida. She'd moved down there and had bought a manufactured home in one of those retirement communities. She said that her roof was leaking. I arranged for my younger brother and I to converge on her home and flew down there.

The roof was metal and had some kind of silver elastomeric coating on it and bituthine seam sealant that was failing everywhere. It was hotter than hell at midday in that home, even with the AC on. We stripped all of the sealant tape off, used an aircraft paint stripper to remove every bit of decades of paints and such from that roof and then we rolled down new vinyl-faced bituthene seam sealer and then coated the entire roof with a fresh white coat of acrylic sealant. The day after we finished, the inside of that home was cool and comfortable with the AC on at midday because most of that heat was being reflected.

She saw a significant drop in her electric bill after that because her AC wasn't running continuously. Total cost of materials was about $300. We put about 10 hours labor into it. It's paid for itself ten times over in the past five years.

Obviously, reflecting sunlight to reduce solar gain has certain advantages in some climates.

ONE TEAM - ONE FIGHT!!!

Mike

[thomop]

I saw a similar thing happening many years back, every one was painting their roofs white. It was supposed to keep the homes cool in summer. Tons of "cool" white paint were sold that year and many thousand labor hours spent in applying this white paint. The savings in energy bills weren't significant enough to offset the cost of paint and labor. The trend has died a natural death.

Not sure I agree with that. Some years ago I got a call from my mother who lives in Florida. She'd moved down there and had bought a manufactured home in one of those retirement communities. She said that her roof was leaking. I arranged for my younger brother and I to converge on her home and flew down there.

The roof was metal and had some kind of silver elastomeric coating on it and bituthine seam sealant that was failing everywhere. It was hotter than hell at midday in that home, even with the AC on. We stripped all of the sealant tape off, used an aircraft paint stripper to remove every bit of decades of paints and such from that roof and then we rolled down new vinyl-faced bituthene seam sealer and then coated the entire roof with a fresh white coat of acrylic sealant. The day after we finished, the inside of that home was cool and comfortable with the AC on at midday because most of that heat was being reflected.

She saw a significant drop in her electric bill after that because her AC wasn't running continuously. Total cost of materials was about $300. We put about 10 hours labor into it. It's paid for itself ten times over in the past five years.

Obviously, reflecting sunlight to reduce solar gain has certain advantages in some climates.

ONE TEAM - ONE FIGHT!!!

Mike

Hi Mike. We have used different kinds of heat resistant roofing paint also (the manufacturers call it 'membrane') and we found it to be very efective. The makers belive it to lower roof space temp by up to 12 degrees. With our tests however, i say more like 3 - 4 degrees.

Still, every degree is worth it i suppose if other forms of cooling fail or you are trying to implement a green tactic. Just dont know if the cost justifies the exercise.

There has been some pretty in depth studies here that draw conclusions to suggest the idea is worth it. But still nothing major happening.

Was wondering if anyone with a large warehouse or factory has tried this (cool roofs) and whther it has made a difference or not.

[hausdok]

Hi,

Yes, I think they have. I remember reading an article in one of my journals about a very large green/cool roof. I'll see if I can find that article. If I do, I'll PM you with a link to it.

ONE TEAM - ONE FIGHT!!!

Mike