Home with intensive green roof

[Kenton H. Shepard, CMI]

First one I've gotten to do! Of course I disclaimed the roof, but it was a very interesting house.

To learn the difference between "extensive" and "intensive" green roofs, take the InterNACHI Green Building course, or go here.

[Nick Gromicko]

That is wild. Did you get some video of it?

[Mark Nahrgang]

I had one something like that recently. A Realtor who recommends me every once in a while, was a contractor about 20 years ago and built about 200 of these in the area. He needed an independent inspector to write a report for him for his refinance. He showed me the whole house, the design, the engineering papers, etc. The education was more valuable than the fee. Pretty cool stuff. BTW, He has no AC unit. He doesn't even have a furnace, only a single wood stove in the living room. According to him, it takes about a week of a blinding snow storm for the house to drop below 50 degrees without even using the stove. (Heat sink, etc.) It's an amazing technology.

[Kenton H. Shepard, CMI]

Originally Posted by gromicko

That is wild. Did you get some video of it?

You bet! Both video and still photographs. We're building a visual library for our energy courses.

[Kenton H. Shepard, CMI]

Originally Posted by mnahrgang

I had one something like that recently. A Realtor who recommends me every once in a while, was a contractor about 20 years ago and built about 200 of these in the area. He needed an independent inspector to write a report for him for his refinance. He showed me the whole house, the design, the engineering papers, etc. The education was more valuable than the fee. Pretty cool stuff. BTW, He has no AC unit. He doesn't even have a furnace, only a single wood stove in the living room. According to him, it takes about a week of a blinding snow storm for the house to drop below 50 degrees without even using the stove. (Heat sink, etc.) It's an amazing technology.

What about the potential for moisture intrusion? What things did you disclaim or alert your client to? These homes are great if built right, but many, many were built wrong. I see these as a big liability for a home inspector!

Charge a ton, disclaim everything

[Mark Nahrgang]

Originally Posted by kshepard

What about the potential for moisture intrusion? What things did you disclaim or alert your client to? These home are great if built right, but many, many were built wrong. I see these as a big liability for a home inspector!

Charge a ton, disclaim everything

It wasn't a full inspection. I just had to write a letter to his lender giving an opinion on if the current wood stove would be sufficient.

The owner was the builder. Like I said he had done a couple hundred of these in the area (actually all over the country).

I've enlisted him, in case I get a full inspection on one, to help me with any future inspections of them.

If any of them were built right, I would surely expect his to be the one out of all them.

[Kenton H. Shepard, CMI]

Mark, it was an intensive green roof and what the lender wanted to know about was the wood stove? Not the roof?

One of the things about structural green roofs is that it has taken a while to figure out how to build them correctly, and no one is sure that they've done that yet.

A contractor can make the same mistake in each one of several hundred houses built using alternative methods, and in many cases ... they have. As an inspector... you're liable.

InterNACHI has developed methods for inspecting these homes, but it takes time to produce that information.

Protect yourself.

[Mark Nahrgang]

Originally Posted by kshepard

Mark, it was an intensive green roof and what the lender wanted to know about was the wood stove? Not the roof?

One of the things about structural green roofs is that it has taken a while to figure out how to build them correctly, and no one is sure that they've done that yet.

A contractor can make the same mistake in each one of several hundred houses built using alternative methods, and in many cases ... they have. As an inspector... you're liable.

InterNACHI has developed methods for inspecting these homes, but it takes time to produce that information.

Protect yourself.

I'm sorry, I inadvertently misled you. I don't know if it was an "intensive green" roof as you state it or not. It was a concrete building that was buried. Only one side of it was open to the air.

Like I said. I didn't do an inspection. Only a letter stating that the wood stove was sufficient to keep the pipes from freezing in the winter.

AND it was just for a re-fi.

What do you mean... as an inspector... your liable.

[Kenton H. Shepard, CMI]

Originally Posted by mnahrgang

I'm sorry, I inadvertently misled you. I don't know if it was an "intensive green" roof as you state it or not. It was a concrete building that was buried. Only one side of it was open to the air.

Like I said. I didn't do an inspection. Only a letter stating that the wood stove was sufficient to keep the pipes from freezing in the winter.

AND it was just for a re-fi.

What do you mean... as an inspector... your liable.

Sorry Mark, I think I misunderstood.

[Dan J. Payne]

Kenton, I am new to NACHI (3 Weeks) very interesting message board.
This subject really interests me. I notice only 1 layer of membrane for roof waterproof design, very questionable. One minor failure and woops. Suggest looking into PAHS design studies on the subject (my next house design)

[Kenton H. Shepard, CMI]

Welcome Dan!

In this particular home the waterproofing was thick enough to be installed with a trowel. I'd prefer to see multiple layers, but it's been there since the mid-early 80's with no sign of leakage at all. This was a kit home and the original company is still in business with some homes that have been around for quite a while with no problems.

That's a pretty good achievment. It's been my experience that builders specializing in home built using alternative building methods have a significantly higher attrition rate that builders using conventional methods.

I thinks that's because "alternative" actually means "experimental" which actually means "we don't know if we have all the bugs out yet".

[Devin Bolduc]

If you are inspecting such structures you need to be familiar with the types of surrounding vegetative growth. As a brief example, one common and extremely invasive plant is quack grass. The roots of quack grass are powerful enough to penetrate concrete and asphalt. Fortunately the rhizomes do not generally grow deeply in the soil but are/can be an issue at grade, plane and elevation changes.

[Kenton H. Shepard, CMI]

Good point Devin. I don't think we need to identify plants, but there should be language in the disclaimer stating that we don't identify plants as part of the inspection and describing root invasion as a possible source of damage or deterioration.