[rjn5656]

Looking to put more insulation up in attic. Any recommendations?

[retiredguy123]

The Solar Guys get good reviews for solar tubes, and they also do insulation. I would use the blown-in type and add at least an additional 6 inches to the existing insulation. I would not insulate the attic space above any unconditioned spaces, like above the garage and the lanai.

[villagetinker]

Probably not worth the cost. Contact your electric supplier, most have free energy audits, and they can tell you if this would be a wise move. IMHO, unless your home is fairly old and the insulation has compacted, I do not think you will get much savings from the additional insulation.

[GpaVader]

If you are looking to climate control spaces that weren't originally, its also worth considering...

[retiredguy123]

Originally Posted by villagetinker

Probably not worth the cost. Contact your electric supplier, most have free energy audits, and they can tell you if this would be a wise move. IMHO, unless your home is fairly old and the insulation has compacted, I do not think you will get much savings from the additional insulation.

Probably correct in terms of electricity cost savings. You can buy enough blown-in insulation to add 6 inches (R19) to a 1500SF space for about $700 from Home Depot or Lowes. You can also rent a machine and install it yourself. But, if I could get it done for about $1000 or so, including materials and labor, I wouldn't do it myself. You will save some energy and possibly notice a quieter and more comfortable house, and may get a $50 tax credit. To me, this project makes a lot more sense than some of the weird ideas I have read about on this website.

[TheSolarGuys]

Give us a call and we would be happy to give you a quote. Thanks 866-669-5259

[Bay Kid]

Originally Posted by retiredguy123

The Solar Guys get good reviews for solar tubes, and they also do insulation. I would use the blown-in type and add at least an additional 6 inches to the existing insulation. I would not insulate the attic space above any unconditioned spaces, like above the garage and the lanai.

Just curious why not insulate above the garage? Wouldn't that help cool the garage?

[retiredguy123]

Originally Posted by Bay Kid

Just curious why not insulate above the garage? Wouldn't that help cool the garage?

The purpose for insulation is to slow down the heat transfer process between a conditioned space and an unconditioned space. So, you can reduce the amount of energy required to heat or cool the conditioned space. But, when both spaces are unconditioned, like the garage and the attic space above it, the insulation doesn't really do much because, in a short period of time, both unconditioned spaces will reach an equilibrium temperature. That is why builders do not insulate these areas.

[MartinSE]

Originally Posted by retiredguy123

The purpose for insulation is to slow down the heat transfer process between a conditioned space and an unconditioned space. So, you can reduce the amount of energy required to heat or cool the conditioned space. But, when both spaces are unconditioned, like the garage and the attic space above it, the insulation doesn't really do much because, in a short period of time, both unconditioned spaces will reach an equilibrium temperature. That is why builders do not insulate these areas.

Exactly correct.

It can slow down the reaching equilibrium, but not stop it. Adding an "exhaust fan" into the garage will also help. Neither will "cool" the unconditioned area, but both extend how long it takes to get hot. With enough exhaust the best that can be hoped for is to not get "hotter" than the outside temp. But, that is not easy (possible?) to reach, most likely will always be slightly warmer in the afternoon.

[Bay Kid]

Originally Posted by retiredguy123

The purpose for insulation is to slow down the heat transfer process between a conditioned space and an unconditioned space. So, you can reduce the amount of energy required to heat or cool the conditioned space. But, when both spaces are unconditioned, like the garage and the attic space above it, the insulation doesn't really do much because, in a short period of time, both unconditioned spaces will reach an equilibrium temperature. That is why builders do not insulate these areas.

Makes total sense. I guess a roof vent would be a better answer to help cool.

[MandoMan]

Originally Posted by villagetinker

Probably not worth the cost. Contact your electric supplier, most have free energy audits, and they can tell you if this would be a wise move. IMHO, unless your home is fairly old and the insulation has compacted, I do not think you will get much savings from the additional insulation.

My house was built in 1998, and people seem to have tramped around in the attic a lot, perhaps when the original owner was adding a lot of storage up there. In any case, I can see the bottom chord of the roof trusses in places, and those are 4” high. I think my heating and cooling bill isn’t too bad, but more insulation will definitely reduce heat transfer, whether or not it is cost effective. Also, I have a guest room that is always much hotter than the rest of the house in the day. I wonder if it was ever insulated at all. I need to get up in the attic and check. I thought it was morning sun, but I put up a big shutter that keeps the sun off, but the room is still hot.

[retiredguy123]

Originally Posted by MandoMan

My house was built in 1998, and people seem to have tramped around in the attic a lot, perhaps when the original owner was adding a lot of storage up there. In any case, I can see the bottom chord of the roof trusses in places, and those are 4” high. I think my heating and cooling bill isn’t too bad, but more insulation will definitely reduce heat transfer, whether or not it is cost effective. Also, I have a guest room that is always much hotter than the rest of the house in the day. I wonder if it was ever insulated at all. I need to get up in the attic and check. I thought it was morning sun, but I put up a big shutter that keeps the sun off, but the room is still hot.

The insulation can be checked with a machine that can measure the insulation value from below without going into the attic. A home inspector, such as Frank D'Angelo, has such a device which could be used to evaluate the insulation in your house. You may also be able to get an energy audit where they may be able to do the same thing.

[jdulej]

When we bought our second new house, this one in Lake Deaton village, we were concerned that it took hours to cool down the house a few degrees. Since the house had been stretched a lot, one thought was that the AC unit was not powerful enough. TV told us the unit was just fine and everything was as it should be. When we had our 1-year inspection, the inspector came down from the attic laughing - this was a new one for him. Apparently there are measurement sticks attached around in the attic to measure the depth of the insulation - the installer made sure the depth was correct at each measuring stick, but was a low as 1 to 2 inches in most of the space.
The Villages had it fixed - the truck pumping insulation was at our house all day. House heats and cools just fine now.

[spinner1001]

Originally Posted by Bay Kid

Just curious why not insulate above the garage? Wouldn't that help cool the garage?

The theory for adding attic insulation above the garage is to slow the heat transfer from the hot attic into the garage. With insulation, that certainly occurs in some degree. But the practical decision is whether that benefit is worth the cost of the insulation. The trade off is subjective.

I recently added insulation to the garage door and attic above the garage and can feel a noticeable difference in the garage temperature. I believe both have an effect on the garage temperature but I don’t know whether the door insulation or attic insulation has a bigger effect. My garage door faces the sun in the afternoon.

[retiredguy123]

Originally Posted by spinner1001

The theory for adding attic insulation above the garage is to slow the heat transfer from the hot attic into the garage. With insulation, that certainly occurs in some degree. But the practical decision is whether that benefit is worth the cost of the insulation. The trade off is subjective.

I recently added insulation to the garage door and attic above the garage and can feel a noticeable difference in the garage temperature. I believe both have an effect on the garage temperature but I don’t know whether the door insulation or attic insulation has a bigger effect. My garage door faces the sun in the afternoon.

Note that hot air rises, so I'm not sure how much benefit the ceiling insulation provides. I think that adding a ventilation fan to remove the hot air from the attic would provide more benefit.

Follow-up. To test your theory, I measured the temperature inside my garage about one inch from the ceiling. It was 92 degrees, which was the exact same temperature as the outside air. Also, there was only about a 2 degree temperature difference 5 feet below the ceiling (90 degrees). I think that is attributable to the hotter air in the garage moving up toward the ceiling. The attic temperature was about 10 degrees hotter than the outside air. There is zero insulation above the garage ceiling. So, I don't think there is much heat being transferred downward into my garage from the attic.