Recently Insulated --- Now too hot!

JMC · 07-15-2009, 01:52 PM

My bedroom walls had zero insulation so I opened the walls (drilled over 50 holes in the wall) and rented a machine to blow in insulation. All the wall holes have been patched and finished off.... Now the room is at least 5 degrees warmer than the rooms with zero insulation (even with two windows open and a fan running full time).

I was hoping for the opposite to occur. I thought that by insulating this room I would have a room that would maintain a balanced temperature.

What didn't I think of?

Thanks for your help.

Genhawk21 · 07-15-2009, 02:09 PM

Is this a house with an attic/pitched roof? My limted understanding of this is that if so, your heat would rise up to the attic and be vented from there (through the walls you just sealed up). You don't mention if these are exterior or interior walls or both.

Are you running any computers in that room?

concretemasonry · 07-15-2009, 02:20 PM

What kind or circulation do you have in the house?

Are you running AC? If so do you have a return in addition to a supply line?

In addition to heat from the attic/roof, it sounds like you are retaining the heat from inside (either generated by lights and appliances) or by sunlight heating the other areas of the house. That is good in the winter

Dick

stubits · 07-15-2009, 05:33 PM

We're actually having a very similar problem. This winter, we added insulation thinking it would help us both in the winter and the summer. The home is 75 years old and there was no insulation in the attic at all. It helped a lot in the winter and we were able to reduce our gas bill significantly. We were really hoping the summer would be good as well.

However, the summer has been much more uncomfortable, even though it has been a milder summer than last year, and the AC runs a lot more. What is the correlation between this and the insulation? We have a flat roof an absolutely no venting. How would the insulation make the no venting situation worse?

Scuba_Dave · 07-15-2009, 06:22 PM

Even if you only have soffit vents if you blocked them that will cause warmer temps in the winter & also hotter in the summer

If you have a roof where the 2nd floor walls are "roof" then you may have blocked venting also. And if you went to far up the wall you may have blown insulation into the soffit areas. Unusual that it's open from the wall - but ballon framing maybe?

stubits · 07-15-2009, 06:37 PM

Hmmm. Thanks for the info. In my particular case it is an old rowhome with a flat roof and there are not now nor have there ever been vents. Guess that wasn't how they built the 75 years ago. So, I'd imagine without the insulation the roof breathed better, no? Interesting to know that it could cause the problem.

So, how does one vent a flat roof? I am guessing a mechanical vent of some sort, perhaps solar powered? Any recomendations? How big? And the most important question, how can I install it without welcoming leaks. My roof is covered with rolled asphalt material. I will replace the roof eventually, but would love to solve the problem sooner rather than later. Any thoughts?

JMC · 07-15-2009, 07:20 PM

The roof is an attic pitched roof. There is a small crawl space only. Do you think this area needs to be vented to release the hot air....while before the walls vented the air?

TooledUp · 07-15-2009, 08:00 PM

Yeah, I definately agree with scuba_dave. There probably is no venting now. Do you have any vents on your roof??

Mike in Arkansas · 07-15-2009, 09:23 PM

MY WAG would be little or no attic insulation. You ceiling is a big radiator (especially in the evening and at night) and your insulated walls are now retaining that heat where before it could escape through convection or air leaks. Boost the attic insulation. just my .02

stubits · 07-16-2009, 12:41 PM

Hmmm. Thanks for the info. In my particular case it is an old rowhome with a flat roof and there are not now nor have there ever been vents. Guess that wasn't how they built the 75 years ago. So, I'd imagine without the insulation the roof breathed better, no? Interesting to know that it could cause the problem.

So, how does one vent a flat roof? I am guessing a mechanical vent of some sort, perhaps solar powered? Any recomendations? How big?

And the most important question, how can I install it without welcoming leaks. My roof is covered with rolled asphalt material. I will replace the roof eventually, but would love to solve the problem sooner rather than later. Any thoughts?

Chemist1961 · 07-19-2009, 08:18 AM

Try reading up on your roof type at this site
www.buildingscience.com

READ UP ON IMPROVING YOUR INSIDE VENTILATION AND AIRFLOW AS WELL TO BOOST THE EFFECT OF THE AC