InterNACHI members, how useful would you find maps?

Hi all, I’m a researcher and technical writer for InterNACHI, and I have a question for all of you.

At InterNACHI, we’re always trying to come up with new educational resources for inspectors. One idea we had was to create, in addition to our graphics library ( and our article library ( a MAP library. Why would inspectors need maps? Well, we’re not talking about road maps, we’re talking about thematic maps based on inspection-relavent themes. Of course, inspectors are really only concerned with conditions in their area rather than those far away, so it’s a leap to think that thematic maps will be an indispensible tool. Still, I’d like to throw it out there and see if anyone would find them useful. So let me know - useful, or useless? Take a look at a few examples and ideas I found:

  • A map of radon across the USA

Or a detailed radon map of Virginia

  • A map of termite infestation across the USA

  • Mold growth potential across the US

-A map that shows how different jurisdictions or states handle different building codes. For instance, one state may require AFCIs while another might not, and it could be useful for the traveling inspector to have a map that explains this difference.

I think you’d be on to something.

I would/do find them useful. Sometimes difficult to find them, when I need them.

Meth . . . Chinese drywall . . . Wood chips (insect-laden) from Katrina . . .

Keep going - Great work so far, Rob!

Some of them would be useful, but site the source on every one. Many are missleading…

Like the one above showing radon levels.

If you look closely, the radon level in Missouri is in the moderate section, and it just magically follows the east and north boarder of the state. Naturally occurring phenomenon rarely follow arbitrary human borders. This map is in error because of politics and ignorance. And (at least) the north half of the state should be in the high portion.

I spent 15 years in the computer mapping industry, and I can tell you with expert confidence that you can (and people do) lie with maps.

I would use them, possibly on my website.


That is more info we can pass on to our clients. However, our state lists test results for individual counties and a link to the county look-up pagewould suffice.

Oh, we would be creating the maps, not taking them from other sources.

Yes, that Missouri example is a bit misleading now that I look at it. I think they probably just didn’t have enough information for that area so they guessed by using the state border. Still, I think it would have been better to color that area and represent it in the key as “unknown” rather than just guessing. Good point.

At the time the EPA was gathering info from the states, the guy in charge here in MO didn’t “believe” in radon. He mandated that no “elevated” test results would be passed to the EPA unless they were 10.0 or above. The EPA made the map with the data they had. So the number of tests that were considered to not be elevated were artificially large, this lowering MO’s overall values for the counties.

Once again… politics and ignorance.

BTW what software are you using? I spent 15 years teaching GIS for the world leader in the field. I’d be happy to consult with you if you have questions (It’s been about 4 years, so I’m a little rusty. But glad to help any way I can.)

I’d be using ArcView by ESRI, I’m sure you know what that is if you taught GIS for 15 years! I’m actually getting a degree in GIS, although I’m pretty rusty myself because I’ve taken off time to be Nick’s go-for boy hehe. I would certainly enjoy your help if we decide to go through with any of this.

Thanks for the responses guys, keep em comin

I worked for ESRI… and used ArcView before it was ever a real product. Call me if you have any questions.

I think they would be very useful at times. Canadian content would be greatly appreciated for us Canucks!

Thank you all. Can any of you think of specific instances where maps would be useful for you? The radon and termite maps were the first things that came to mind, but they are already readily available. We need some novel, useful ideas.


For me, I think the best use would be to be able to geocode addresses: I’d like to know where agent offices are relative to my inspection so I could make marketing visits. I’d like to geocode the addresses of the homes I’ve inspected to see where hotspots of work are, and where voids are. I’d like to geocode hotspots of agent offices to see who is recommending me and who isn’t.

I know you were thinking of generic maps. But for me the applications of geocoding and analysis would be the most valuable. And no, I’m not going to invest in ArcView to do that. But if there is a product that you could serve on the NACHI site that would be awesome.

I had never put a jpg of a map in my reports. I would if I had an InterNACHI map available. That would blow my competition away. It’s a sign of an intelligent, thoughtful report. I would incorporate an ENERGY map, a map telling my client what R-values are required/recommended in the ceiling, walls, and floors.

If I were doing an energy inspection, I would use an ENERGY map.

I’m using Google maps to keep track of where I tested for radon and what levels they were. Mark has some good ideas also.

Termite infestation in WA is “low”? :shock:

It would be helpful to find things and more…

I also like Mark’s idea.