Roof Melt can tell you a lot

It’s the most wonderful time of the year.  The season of giving outward information about your thermal resistance.  Roof Melt season.  So what is roof melt season.  That is the time of year when we get light snow fall and the opportunity to visualize surface temperatures. 

What am I talking about.  Well, Insulation is the resistance to thermal energy transmission. Think about that practically. How does heat sneak out of our houses? It escapes the exterior surfaces of our house.  How do you tell that heat is escaping an exterior surface? It is warm. Or at least warmer than the surfaces around it. So you could use an infrared thermal imaging camera to take a picture of the surface temperatures, but those are very expensive and you get pictures like this.

Snow 1.jpg

So what do you learn from this? The chimney is warm. Windows are warmer than the wall, or specifically the siding.  Knowing the surface temperatures is great, but that alone is not enough to calculate the effective R-value.  It does give us an impression of where the greater heat losses are.  So does roof melt.

Now for the cost of going out and looking, you can learn about the insulation effectiveness of your roof.  Snow on a roof is an indication of surface temperature. Snow is most common between 20°F and 34°F.  Since we are only dealing with a few degrees between frozen and melting, the differences show up quickly.

This roof has 3 different stages of melt.  There are 3 things to learn from this roof.  The roof was clean before this snow. The snow fall was about 2 inches. 

The lower portion of the roof is un insulated.  The area physically under the roof is not heated but the ceiling underneath is heated.  That is melting some of the snow off the roof.

The next section of roof is probably a sloped ceiling that is insulated. None of the snow melted because the roof is the coldest in this range.

The top of the roof has the most melt.  This means that the roof is the warmest.  This would indicate a change in the ceiling to roof construction.  Given the window on the end of house, I would assume that there is a small portion of flat roof that connects to the dormer that extends out the other side. My guess is that the insulation is not on the ceiling.  If the insulation is against the roof and not air sealed from heated space the air will churn between the roof and the ceiling. Insulation is the most difficult and important at the transitions in construction.   

This roof looks good except for 2 specific spots.  The first spot is the where the lower parallel roof joins the main roof.

The spot outlined in orange is the warmest spot on the roof.  The heat is either coming from the ceiling transition or the end wall between the main house and the addition.

There is a small spot in the middle of the roof.  The 2 suspects for that is the alignment with the perpendicular peak of the lower roof.  Warm air pools at the top of a compartment, so any leaks will fill the top of the framing first.   There could be another source on the other side of the roof or just from the compartment below.  Chimneys are commonly located in the center of these houses.  A chimney could be heating this small portion and just not visible in this picture..

This roof has a few obvious issues. The roof compartments connected to the lower roof have the most melt.  There is a ling across the roof of isolated melt. The melt appears to be where the wall or ceiling of the interior meets the roof structure.  Also the framing is showing up in the snow, which means that the framing is colder.  The cold means that the framing is colder than the bays.  This means the bays are uninsulated or the insulation is compromised.

This roof have melt on the lower roof. This means that the insulation is well installed in the most of the upper portion of the roof.

This specific melt is due to leaks from the walls.  The heat leaving the wall hits the roof and melts the snow with an isolated warm spot.  This is commonly due to poor sealing of the ceiling to the wall or penetrations in the walls, like electrical wiring.  Changes, like framing where walls meet or around windows, can cause paths of heat to escape.  As with all snow melt, it is also an indication that the roof ventilation is insufficient to maintain outdoor temperature on both sides of the roof decking.

There is a quick sermon on using roof melt to diagnose you roof insulation situation.  Often fixing these is much more expensive on their own.  Noticing these problems should help give you ideas of what to pay attention to you when you are doing projects in these areas. Fixing the air sealing or insulation while drywall is removed is fairly low cost and low time commitment. Say a few hours and maybe $100 in material.  Always talk to a professional to get some “local” answers. A perfect wall in Alaska can be a nightmare in Arizona. 

I am Mick Lane and thanks for giving a watt.

Starting to gain some steam

I have been hard at work.  Well podcasting and doing home work. The home work is the utility  bill analysis.  Listen to the podcast, check us on twitter. Do your home work and Tweet me your home work?  Sum up 12 months of utility bills.  Take a picture of that sheet and tweet it to me with the has tag #DoThatSheet.

This exercise will help you determine the cost per square foot.  Take the total cost for a year of electric, gas, fuel oil or whatever you use to power your house.  Then divide that by the square footage of the conditioned space of your house.  For the rest of the details, listen to the full podcast.  For those of you who will just listen to the last 2 minutes I will tell you how it ends.  If you are about $1/SF you are doing pretty good.

Find the Podcast here.

Find us on twitter here.

Podcast is up

So finally got things in motion.  First Podcast is up.  And it is about. . . . . Showers.  Energy and water costs.  The good new is a shower should cost less than a stamp.  The bad news is if you listen to this podcast, you will have one more thing to think about while you wash your hair.  It wont keep you from showering, but may limit how far you sing through the Barry Manilow Catalog.

If you don't have the time or care to listen to the whole podcast, then listen to the snippit.  It give you enough to think about changing your shower habits with out enjoying the whole podcast.  This week is actually pretty short at 15 minutes but save your iphone's battery by listening to the snippit.

Podcast

Snippit

Getting Closer to Launching

Hello to those of you stumbling on to this page.  You may have been informed about it by me or through reckless browsing.  The site is a little light on content.  This will be an ongoing effort to add information to the site for people to use in making decisions about energy uses, choices, improvements or just trying to save a few bucks. 

The first entry may be my most recent presentation I did for a group of "energy professionals".  It included the thought process for correcting overheating and even some real equations and math.  It is a little bit over the traditional home owner but the savings math does not require any magical software or bizarre weather data.

If you have a question about a specific energy topic send us an email addingenergy@gmail.com or tweet us at @addingenergy.

I look forward to talking to you soon.

Mick Lane

In the beginning there was

Glad to finally be moving on this venture to share my wealth of energy knowledge with you all.  Don't look for endless blog posts or sustainable shaming.  I would rather have you make your own educated opinion, than have you agree with me today.  Feel free to change you opinion as often as you like.  

Energy, sustainability, green, have become buzz words.  Obviously we want to be good stewards of the planet and resources, but we also want to be stewards of our homes, cars, families and money.  Let's shuffle this deck and put people at the top of this list.  Now you may order all those other things in whatever order you wish.  I hope that the information I provide will help you to do that.

The last thing is I want you to understand some of the terms and technologies that are part of energy usage, energy efficiency and energy issues.  The worst that could happen is you buy a hybrid to get 50 miles per gallon and end up with 20 because you didn't take the kayak rack off the roof and the 6 cases of water out of the back seat.

Again, this is site is not meant to save the planet.  It is to make you aware of you energy usage and help you add energy to your dollar decision making.

Thanks for giving a watt.

Mick Lane