Unfortunately I hate to say I think I know the answer to the question. My new home is now at drywall stage. I caused some big waves between the builder and the city of Airdrie. Because the builder says that this method of insulating the cantilever was fine and they did it that way in all their homes. (Mike Holmes You can Come to Airdrie and Fix all the cantilevered homes in this subdivision.)The city inspector put on her deficiency that it should be vapor barierred but then told the contractor it was not required? She also told me that they have had issues in the past because of moisture getting trapped under the vapor barrier. Not sure if I got what she was talking about. She also said that spray foam was the best way and so did the sub doing the insulating but the cost was too much for most of the poor builders to handle. So I guess my question is how concerned about this should I be? Should I be ripping up the floor in the bedroom above in a couple of years and dealing with this or is this something that is really some what the common practice in alberta? Note, for some reason their was vapor barrier under the insulation and above it (That would be under the floor in the room above) What real purpose this served I am not sure. And as you can probably guess I am no-longer allowed in the house until walk through time. Thanks for any help or reassurance on this matter.

What insulation material did he use? Was it rigid foam board?

It was a batt not the pink fiberglass but a white batt r20.

You will likely get condensation and mildew. You contractor isn't as smart as he thinks or he is just lazy. You need a vapor barrier

I know I guess I will have to rip open the floor and get it spray foamed myself. I know all the other houses in my naibourhood are done this way because the builder told me so. Fed up getting ripped off by idiots. I will have to wait until my house is complete at this point as I don't want to make life worse for myself by causing grief with the builder. I already tried that and even the City building inspector let me down. Actually it's the contractors fualt as this is the way they choose do things. I am sure once people on my street find out about this someone may have some explaining to do. Not sure what else I can do at this point? Thanks for you help.

"cause the builder told me so" , come on they lie just like anyone else. You builder is your general and the insulation contractor is his sub. The general reports to you and you need to just crab your head off at this guy and make a lot of noise. Ask the inspector which code they follow. Not all codes are the same but a vapor barrier is LAW in most. Vapor Barrier Required in Building Code - Tips for Homeowners

I already tried all that and at first the city inspector told them to install vapor barrier. I even saw her report saying it should have vapor barrier. But when the contractor called her to complain about the fact that she let it pass in the other homes. She told him he could leave it as is. I think she may have missed this in all the other homes and is covering her behind."?" I don't know. She also told me that the city had no clear code on how cantilvers are to be insulated? She stated that the best way to insulate them was to spray foam them but "some" builders don't want to pay the extra cost. You have to realize that I am going to be homeless in two weeks ( my home is sold and my family and I are asking friends to put us up until the house is complete) and I don't want to delay things at this stage. I have a year warranty and what I have going for me is the fact that I work for a plumping company with a recording snake camera that I will stick in the floor through the heating boot. I will have to wait for some cold weather next winter but the ice will be there I am sure of that. The threat of going door to door with the evidence may get things fixed by builder. They should be around by then as they have been in buiseness for at least 15 years. I have also emailed the City of Airdrie building dept. for clairification on this code. It's to bad building inspectors have zero acountability. Not sure what else to do at this point. Hopefully I at least get an email from the city. I would like something in writing.I will let you know how it goes.

"the city had no clear code " my guess that this is a bold faced lie. Ask the city which code did they adopt. There are only 2-3 major codes and cities adopt one of them and insulation is covered.

I have the response e-mail from the city inspector . This is what she said...


The 2006 ABC Article 9.25.4 for Vapour Barriers states:
 
1)       Vapour barriers shall be installed to protect the entire surfaces of thermally insulated walls, ceiling and floor assemblies.
2)       Vapour barriers shall be installed sufficiently close to the warm side of insulation to prevent condensation at design conditions.
 
These sentences require that a vapour barrier be installed in your floor assembly and should be installed as close the warm side as possible to prevent condensation.  A vapour barrier shall have a water permeance not greater than 60 ng.  Cantilevers are not an easy area to insulate and vapour barrier, as there are many other issues that also need to be addressed, like ventilation and cold spots.
 
Floor sheathing can be considered to be a form of vapour barrier.  So, this does help reduce the amount of moisture getting into the cantilever space. 
 
Putting the vapour barrier right in front on the warm side makes it impossible for the warm air to travel into and out of the cantilever area, making these floor areas very cold and reduces the airflow that we want for removing any condensation that does occur. 
 
Strapping a vapour barrier tight to the floor sheathing does not allow for any moisture to escape the floor. 
 
Putting the vapour barrier on the bottom side of the cantilever, behind the insulation is not technically on the warm side of the floor, but it does allow for air movement and does get the vapour barrier in the floor.
 
I would recommend that you email Alberta Municipal Affairs and ask them your questions.  As I mentioned on the phone the other day, this issue is something that comes up all the time and as of yet I have been unable to get a solid answer on how I should be calling these installations as there is not a perfect installation method that addresses all issues.
 
When I inspected your house for the insulation and vapour barrier installation I was satisfied with the installation as it was done with a few minor corrections.  IF you have any other questions feel free to contact me again at any time.
 
Regards,
So I spoke with the site supervisor and he said He would have a look at it . I am starting to feel sick to my stomack about this whol deal. We will have to see what happens.

The city should not allow cantilevers if they can't find a way to insulate them. My next Question is how should I GET THEM TO FIX THIS NOW? The drywall is up,, he mentioned removing siding and outside sheating and getting at it that way. Would filling the whole cavitiy with sprayed in foam fix things once and for all? Thanks. Mike M

Foam would be a great solution but you can't just pump it through a hole. It is sprayed from a spray gun much like paint, it expands to moment it hits the surface. However that same building code states this about Foam "The product is not exempt from the requirements for vapour barrier and dampproofing (interior below-grade walls) as required in Subsection 9.25.4. and Article 9.13.3.3. of the NBC 1995, respectively" so you still have a problem

I have in the past put solid blocking between the floor joist where the cantilever begins separating that part from the rest of the floor then installed fased insulation in the cantilevered area paper side toward the living space the paper is considered a vapour barrier and put round pop louver vent at both end of each bay.to my knowlegde every thing is still fine with those jobs.I still work in the same area and get call backs for new projects with some of those costomers.

carpenter-t's use of venting will also help. Good call

The builder said the will remove the aluminum soffit and re-do the insulation and vapor barrier from underneath the cantilever. As to what they will do I don't know. Probably I will have to rip un the carpet and subfloor in the future and get it spray foamed. There are other issues with the rest of the vapor barrier in the house. Like no seal between overlapping sheets of poly. No seal at the ceiling rafters. They did use acoustical caulking in a lot of places but not enough. Staples used to hold the poly have no tuck tape. Only tuck tape is around boxes, Where they did use boots and around other plumbing pertrusions. They did spary foam (from a can) holes for wiring. No tuck tape on the outside home wrap.Not sure if that is really requiered but other builders in the area did use tape. I did go into the house in the evening after the contracors left for the day and caulk and tape here and there but not enough to make a huge difference. Over all I would never buy a new house again without asking some very specific questions about construction methods and getting it in writing. Minimum codes don't always cut it, if they even met minimum code. I think the city inspector that was at my home may have some explaining to do to her boss at Alberta Municiple Affairs. Not that it does me a lot of good at this point. There are other things that are not to code that are not difficult issues to fix which I will bring up during my final wald through. Not sure what else I can do at this point as drywall is, up mudded and ceiling is sprayed. I tried my best to keep from becoming one of those people you hear about getting hosed with some builders and in the end I still kind of got it.

If your that worried about the insulation in the cantilever area why not pay the extra to have it sprayed when the contractor opens it from out side.and if you do it down the road a bit still do it from out side it will be easier and lest costly,not to mention keep the mess out of you house.as far as duct tape I have never seen any body tape over the staples or seams.besides duct tape doesn't stick well to poly it usually falls off over night.

Because the builder will not let me do that. Something about voiding my warranty if I have work done myself. And I meant tuck tape that red tape.

Tuck tape I've only used out side on tyvek and only if the siding was'nt going on for a while.

Neither tuck tape or duct tape is the right product to use. There is a red Tyvek tape or http://www2.dupont.com/Tyvek_Weather...20Bulletin.pdf

Foam would do it -from underneath so no interior finishes need to be disturbed.
But you don't need to fill the whole thing with foam. Installers only spray on a couple of inches at a time to allow it to 'cure' properly. And you'd only need the amount required by Code for floors (Floors above unheated space -in Manitoba- must be R-28), and at R6.5/in.(spray polyurethane), 4 1/2" of sprayfoam (polyurethane) would be needed.
I'm an architect and I'm facing the same problem myself on a project. Opinions vary, but from my research, this should work. I stand to be corrected if any 'experts' out there have other opinions.
James