I need to reduce the Roof cooling load on a house in Florida


#1

Just purchased a Mobile Home which of course does not have an attic. The roof is black shingles. What are effective ways of cutting down on the Cooling Load for such a roof ? Would a Tin Roof put over the shingled roof help alot ? What about using large sections of sheetmetal (since im an HVAC guy) fastened to the existing roof ? Is there a reflective coating I can apply to the shingled roof to reduce the cooling load ? Have people installed an additional ceiling inside and insulated the cavity to help the situation ? The roof faces south and there is no shade hitting the roof. Thanks .


#2

Hi,

Will your community let you do this?


#3

How about blown in insulation ?

Installing a power vent?

I don’t like the idea of attaching sheet metal at all.

James


#4

[quote=“Lefty”]Hi,

Will your community let you do this?[/quote]

Its a Mobile Home way out in the woods and in an area where there is no community, development, etc…


#5

[quote=“JamesFL”]How about blown in insulation ?

Installing a power vent?

I don’t like the idea of attaching sheet metal at all.

James[/quote]

A Mobile Home doesnt have any attic space so a power vent cant be added. The 6" of space between the inside ceiling and roof, already has insulation in it. Do you like the idea of adding a tin roof over shingles ?


#6

David, while a dark asphalt roof will trap heat and is energy absorbing a metal roof will reflect solar energy, granular coated metal roofs will more so reflect so called solar radiation and reduce energy consumption. It seems manufacturers do recommend an install over one layer shingles, check out the cool metal roofing coalition’s site for more info


#7

Thanks. I was hoping someone would tell me a metal roof could be installed over a shingle roof.


#8

Theres a shingle roof I pass quite often at a apple orchard that was silver coated years ago. At first I thought the guy was a goof. I guess I still do but man it still looks silver and seems to be lasting along time.
If your roofs in decent shape and not under the scrutiny of others id give it a shot before I screwed sheet stock over it.


#9

If you are looking for a quick and cheap way of addressing your problem, I would just apply a urethane coating over the shingles. Heck, if you want to save even more money and don’t have ponded water on the roof, you could even go with an acrylic coating. All you need to do is go to a roofing supply and buy the product and brush. Although, some roofing supply companies won’t sell to the general public; I’m sure you can work around that since you are a contractor of sorts.


#10

metal roofs are installed over shingled roofs all the time, usually adding a 1x4 spacer 2-3 ft OC for ventilation . Check with a manufacturer for specific details. The ventilation 1x4’s helps with oil-canning, and also gives you a predictable area for screws ./fastener installation.

David

also, a lighter color asphalt, and even some of the newer darker colors are somewhat reflective. White being the best reflective after aluminum.


#11

Isn’t there some kind of spray on coating that is supposed to be for energy saving? Seems like it might be a foam? I remember reading about it but maybe it never caught on…dave


#12

You can use SPF, I think cerebus got it though with the urethane coat, base coat and primer first, and don’t forget to power wash it.


#13

I read up on Gardner Silver Reflective Roofing Paint and im going to go this route. It also seals pretty good im told. Ill bet it will help and maybe prolong the roof decking. Thanks for all who responded.


#14

[quote=“Ibedavid”]

I read up on Gardner Silver Reflective Roofing Paint and im going to go this route. It also seals pretty good im told. Ill bet it will help and maybe prolong the roof decking. Thanks for all who responded.[/quote]

You’re going to aluminum coat your shingles? Good luck!

Personally, I’d stick to the urethane coating, but do as you wish.

BTW, if you are hell bent on using aluminum coating, make sure you stir it real well. When you think you are done stirring, then stir it a little more.


#15

black shingles in florida is just hot.
ditto jamesFl,
if that dont work then you need to get rid of the black shingles.
shingles on trailers in florida usually dont have enough slope for metal, so get us pics before you go that route.

gweedo.