Thermal Imaging and Home Inspections

We’ve been using an infrared camera at random home inspections for the past several months, and we’ve decided that this is by far the coolest home inspection tool in the world.  It’s also pretty useful.  Today I’m going to share some of the problems we’ve been able to identify with this camera that we might not have identified without.

Roof Leaks

With all of the ice dam inspections we’ve done in the last month, we’ve looked at a ton of leaking houses.  For each photo in the series below, I made a duplicate of the original image, then overlaid the thermal image on top of the original.  It’s pretty easy to identify the wet areas in the thermal images, but they’re not apparent in the original photos.

All of the homes shown below had roof leaks from ice dams.

I could share more, but I’m pretty sure I’ve made my point.  Thermal imaging can be used to find roof leaks.  The one caveat to finding roof leaks is that the conditions have to be right; if it’s a hot summer day and there hasn’t been any rain for a week, forget it.

Hot Spots In Attics

Warm attics cause snow to melt, which is what causes ice dams.  I’ve found an infrared camera to be invaluable while troubleshooting the causes of ice dams.

The photo below shows a warm spot in an attic that I never would have identified without an infrared camera.  The culprit was a flush-mounted light fixture with light bulbs that had too high of a wattage.  I don’t make a habit of taking apart light fixtures to check the wattage on light bulbs, but I’ll do it if something tips me off.

Uninsulated ductwork in an attic is also a problem; the heat loss is quite obvious with an infrared camera.  The photo below came from an attic with an insulation value of R-60.  Who would have thought it?

Recessed lights are a huge contributor to warm attics, whether they’re airtight or not.  I’ll be writing a blog about this soon.

Improper Insulation

This is one of the most obvious uses for an infrared camera.   The photo below shows an attic access panel that wasn’t properly insulated.

This next image shows an interior wall that was very cold, because there was a missing section of insulation in the attic behind this wall.

The photo below shows the same section of wall, as seen from inside the attic.

In the photo below, there is an obvious cold spot where the insulation was missed or improperly installed.

Heating Systems

If a radiator doesn’t heat up properly, it will be quite obvious with an infrared camera.  The photo below shows a radiator working properly; while I’m not demonstrating a problem here, I just thought this was a cool image to include 

If there are voids or leaks in heating tubes for in-floor, in-wall, or in-ceiling heat, an infrared camera will probably find them.  The photo below shows an inconsequential gap in the tubing at this heated ceiling.

I’m sure I’ll have plenty more interesting photos to share as the months go on, but these photos should help to answer the question everyone asks: “Why would I want an infrared scan with my home inspection?”

For the record, one thing we don’t offer and never will offer is infrared scans on stucco homes in lieu of invasive testing.  I’ll have more on that topic another day.

Reuben Saltzman, Structure Tech Home Inspections - Email - Maple Grove Home Inspections

    

Do We Have Chinese Drywall In Minnesota?

A few times each year, I have a friend or family member ask me about Chinese drywall.  Drywall imported from China during the big building boom after hurricane Katrina had high levels of elemental sulfur, which caused problematic hydrogen sulfide emissions.

What?  You don’t know what that stuff is?  That’s OK, I don’t either.

What I do know is that these emissions have a very strong rotten egg odor, cause major damage to homes by destroying copper, and cause health problems in the form of allergy-like symptoms, as well as headaches and nose bleeds.  Homes that have Chinese Drywall are being completely gutted, because the repair requires replacement of the drywall and replacement of the copper in the home – plumbing pipes, electrical wires, electrical panels, air conditioners… etc.

Most of the tainted drywall ended up in Florida and the surrounding states, but wasn’t limited to just those areas.

Do we have Chinese drywall in Minnesota?

Should we be worried about Chinese drywall in Minnesota?

To my knowledge, no.  As of 1/7/11, the Consumer Product Safety Commission (CPSC) has received two reports of Chinese drywall in Minnesota.   There are no confirmed cases of this stuff in Minnesota, and I don’t think we’ll get any.  Why?  Because it’s so bulky.

I don’t think it makes sense to import drywall from China, then transport it all the way to Minnesota.  At the time I’m writing this post, a 1/2″4′x8′ sheet of drywall is selling for $4.40 at Home Depot.  This sheet of drywall weighs 54 lbs.  That comes out to about $0.08 / pound.  I’m no expert on transportation, but I do know that the heavier and bulkier something is, the more it costs to transport.

So what about those two reports of Chinese drywall in Minnesota?  All it takes to file a report with the CPSC is to fill out a form on their web site.   I sent the CPSC an email asking about this, and they responded by sending me a 1.3 megabyte text file that contained database information of every case reported since 2005, along with a few other documents I assume were supposed to help interpret the data, but I found them to be quite useless.  If you’d like to see the files yourself, I’ve posted them at my web site here.

Both reports for Minnesota were received by the CPSC in 2009; one was in Orono, the other in Burnsville.  I wasn’t able to figure out how to interpret the data, but a helpful person at the CPSC informed me that neither one of these were confirmed cases.

In other words, there hasn’t been a single confirmed case of Chinese drywall in Minnesota.

Reuben Saltzman, Structure Tech Home Inspections - Email- Minneapolis Home Inspections

    

Ice Dams, Pantyhose, Salt

Ever since I was a teenager working at a hardware store, I've heard of people filling up pantyhose with salt and tossing them on their roof to create drainage channels in ice dams.  After hearing about this so many times and even seeing this method of creating drainage channels in ice dams on the news, I began to believe this actually worked.

Nevertheless, I tend to question everything, and last year I finally got around to testing this method on my own.  Instead of laying the pantyhose perpendicular to the ice dam, I laid them parallel to the ice dam in an attempt to get rid of the ice dam entirely.  As I mentioned in my blog about how to remove ice dams, this didn't work well at all.

Several readers suggested I place the pantyhose the way everyone else does (does everyone else really do this?), perpendicular to the ice dams.  The whole idea of placing them perpendicular to the ice dams is to create drainage channels for water, so water doesn't back up in to your house.

I tried this on a cold January day at my neighbors house (thanks for being a willing participant, Jonathan).  I was also curious as to what magical properties the pantyhose possessed.  How do pantyhose make salt so much more effective than salt alone?   Wouldn't it work a lot faster to just put salt directly on to the ice dam?  As it turns out, yes.  This works way better.

The photos from my little experiment are below.  I filled one of the pantyhose up with "Ice Melt", which contained a blend of calcium chloride and rock salt.  I filled the other pantyhose with an ice melting salt that didn't have the contents labeled - I suspect it was just rock salt.  I also poured the Ice Melt in a perpendicular line along the ice dam, using far less salt than I used in either of the pantyhose.

10:00 AM (Start Time)

 

2:00 PM

 

4:00 PM

 

Hmm... it looks like we have a winner.  If you're going to put salt on your roof, I don't understand what the purpose of using pantyhose is.  The obvious thing here is that salt applied directly to an ice dam is far more effective than salt in a pantyhose.  So you can run and tell that.

Reuben Saltzman, Structure Tech Home Inspections - Email- Minneapolis Home Inspections
    

PREVENTING ICE DAMS FROM THE EXTERIOR

I’ve been doing a lot of attic inspections for Minneapolis homeowners with water leaking in to their houses, and in almost every case I find obvious problems in the attic that should be addressed to either prevent or significantly reduce ice dams.  I mentioned most of the stuff that I look for in last week’s blog about preventing ice dams.

Occasionally I’ll come across a house with no attic space in the areas where heat loss is occurring, or there isn’t access to the attic areas.  In these cases, it probably isn’t cost effective to fix the problems that are causing the ice dams – the ‘repairs’ would outweigh the costs of controlling the ice dams.  In those cases, I recommend ice dam control from the exterior.

Remove The Snow

If you rake the snow off your roof, you’ll keep ice dams to a minimum.  This becomes a constant chore, but it’s better than dealing with water leaking in to your house.  Just raking the first several feet of snow from the eaves is usually enough to prevent the formation of ice dams, but in some cases, this will cause ice dams to form higher up on the roof.

I have one very low-sloped section of roof at my own house where even closed-cell foam wasn’t enough to prevent the formation of ice dams, so I get out there with a roof rake and pull the snow off my roof.  This is a perfectly safe way of removing snow, as long as you don’t get too close to your overhead power lines.

This is also a very effective way of preventing ice dams, but it won’t work 100% of the time.  This year,  for the first time ever, I actually had another ice dam begin to form higher up on my roof just past where I had stopped raking.  That was crazy.  I ended up removing almost all the snow on my roof with a super-long roof rake, and that worked very well.

For owners with two-story homes where using a roof rake from the ground isn’t practical or possible, the options are to risk your life getting up on an icy roof to shovel the snow off, hire someone else to risk their life, or install roof de-icing cables as a preventative measure.  I say go with the de-icing cables.

De-Icing Cables

Roof de-icing cables, also known as heat cables or heat tape, should be a last resort when it comes to preventing leakage from ice dams.  De-icing cables themselves aren’t cheap, it’ll cost money to have them professionally installed, and they’ll cost money to operate – between five and eight watts per foot.  On the flip side, they’re very effective; it’s pretty much a guarantee against leakage from ice dams.  They won’t prevent ice dams, but they’ll keep enough ice melted to create drainage channels for water, if installed properly.

If you choose to install roof de-icing cables yourself, here are a few tips:

• Measure the areas where you need to install your de-icing cables first, and buy appropriately sized cables.  For a simple 15′ section of roof with no overhang, a gutter, and one downspout with an extension, you will need a 60′ heating cable.
•  The cables should extend 6″ up the roof past the exterior wall line, through the gutters and downspouts, and 2/3 of the way up the valleys.
• Don’t bother removing the snow from your roof; you could damage your cables, and you could potentially create another ice dam higher up on the roof, defeating the purpose of the heating cables.
• Don’t expect the snow and ice to melt the way it does in the promotional photo above.  The photo at right, which I took at a real house, is what this stuff is going to look like.  Don’t worry, this is normal.

If fixing the causes of your ice dams isn’t a possibility and you can’t safely remove snow from your roof, install some de-icing cables or de-icing panels.  This is oftentimes the most cost-effective way to prevent leakage.

Reuben Saltzman, Structure Tech Home Inspections - Email- Minneapolis Home Inspections