So last night was pretty brisk, being 52 at my house this morning.

I have some additional insulation to put in my attic but I have been waiting for the cooler weather.
So I just got out of the attic, it is already over 100 degrees up there from just 2 hours of direct sunshine. Compare that to it's still only 60 outside.
When you can't see because the sweat is dripping in your eyes it's time to quit.
I think I need to improve my venting as well.

gotta go buy some evacuation fans.

 

Do you have dark colored shingles? 'cause that'll do it.

The first year I lived in my condo, we realized the upper level was all on the same 15A circuit, and there was no way I could run the air conditioners in both bedrooms in addition to computers and televisions. So I unexpectedly had to wire a new circuit in the attic in June. I brought the digital thermometer up there, and it got up to 130

 

not black at least but a dark brown.
yep at this time of year it's about a KW per sq meter.
so that would be about a 64KW heater running, just on the front side.

 

too bad we couldn't harness all that heat and pump it back into
the house in January when it's really needed!

 

My roof is slate and it literally turns my attic into an oven.. Maybe a month ago, the alcove at the top of the stairs leading up to the attic got so hot, that it set off the smoke alarm! The attic has ventilation fans so it wasn't nearly as hot in there.

 

I did the attic insulation last year. I found if you put up aluminum foil ($20/500 ft at sam's club) up first, you rellect up to 25 degrees (ie 85-90 degrees instead of 125) before it hits your insulation...a very surprising result from just a layer of foil.

Get a laser thermometer gun from ebay for $30ish, then you can see where you compare before/after, and also see where you need to reinforce your efforts.

You will find if you do a graveyard shift, you can get more done because it is much cooler.

If you are really inclined, use tyvek to keep your batting pillowed up to the wall and also put as heavy as insulation around your vent tubes as that is your interior living air as well and it will conduct heat into your house...I used the tyvek to surround the tubes and then stuffed the r30 insulation between the tyvek and tube.

Goodluck

 

How well does the Aluminum do regarding trapping moisture against the ceiling? I'd think that could be an issue down the line.

 

I actually doing a foil-foam-foil hybrid to create a marginal conditioned space in the attic. and yup,very concerned with the moisture/condensation issue.
If I can get a 25 degree shear I'll be in fat city though.
If I get condensation I'll need to do two layers with dead air space between, which will yield almost R-40.
Hard part will be installing in the scissor jack area. The master ceiling rises at a 30 degree angle and the roof line rises at a 45 degree angle. this means I''m installing into a 15 degree wedge from above while lying above insulation.... yeeehaah with a bum knee in 100+ temperatures.
WTF was I thinking.

 

My roof has slats as the first layer so any moisture above it is vented. You will find that as you staple the foil up, you don't get a perfect barrier so there is lots of ventilation.