Attic heat?

Question

I have a house that is shaped like a "T" with the top of the T facing the breeze. This blocks the breeze from the remainder of the house (the trunk of the T). The house has a comp roof. When I bought the house there was no attic ventilation except some small eve vents. It gets very hot up there and the trunk of the T part of the house gets very hot. So, I put in two gable vents. I didn't put in a third one because the rain hits against that side of the house. This did not help. So, I put in a solar gable vent fan. This also did not reduce the temperature in the inside part of the house (trunk of the T). So, I put in a radiant barrier on the floor of the attic and this did not help either. I looked into putting on a ridge vent but the information I read said I'd have to then seal up the gable vents. Now I am considering painting the roof with titanium reflective roof paint which will cost ~$2200. Does anyone have any other ideas, preferrably less expensive?

Answer 1

What you really need is soffit vents. That allows a flow of fresh air from the floor of the attic up to the gable vents. Gable and any other type vent, including ridge vents, cannot vent heat from the attic unless there is an alternate way of allowing fresh cooler air in.

Of course, the perfect solution is a combination of ridge vent and soffit vents. However, you could also install motorized power vents with one sucking air in one end, and the other blowing air out of the other end.

One other thing. Don't be afraid to put a gable vent on the rainy side of the house. The shape of the louvers sheds the rain water down, and not in.

Answer 2

If you have a pool, there is a heating system for your pool you can install that uses the heat from the attic.  It heats your pool and cools your attic at the same time.  It won't be cheaper than your roof paint, but at least it has a dual purpose:

http://www.solarattic.com/

Answer 3

Don't paint the roof. You'll be adding $2200 to shingles that will not last any longer than they would without the paint. Putting lipstick on a pig.

Take that money, (plus a little more), and have a metal standing seam roof retrofitted over the shingles. Ask the contractor to use "Galvalume", which is galvanized steel sheet with an aluminum coating, (be sure to specify "domestic" material rather than "imported", some things are still better when made in the USA), it will stay shiny thereby giving you the reflective quality you are after.

By leaving the shingles under the metal, you have an added insulative value, plus it's cheaper, faster and cleaner and environmentally friendlier than tearing them off and hauling to a landfill.

If you want to go the extra bucks, you can have the contractor install a layer of foil faced foam insulation board under the standing seam.

(The metal and say 3/4" foam board, and 1X4 runners for nailers on top of your old shingle roof will still be substantially less weight than another layer of shingles would be.)

If you do that, you will have to wear a sweater to go in your attic in July. ;-) plus, it's the last roof you will ever buy for that house.