Thread: icynene (foam) insulation and recessed lighting

I have a home that's been designed with a vaulted/cathedral ceiling in the living room. The ceiling in this room is literally at the level of roof decking.
It'll be Insulated with foam and then covered in drywall.

Plans call for recessed cans (4) to be installed in this area.
The roof rafters are 2x6 (5.5") - and the cans will obviously protrude into the area with foam insulation.

I can't find anything in terms of code that relates to foam insulation and IC (Insulation Contact) cans. My suspicion is that IC cans are designed for use with fiberglass batt or other insulation that is able to "breath". Icynene for all intents and purposes is air tight and I believe we'll have sigificant heat build up.

Removing the Icynene around the cans isn't a very "green" option and I believe that we'd still have the same problem - too much heat radiating in from the roof decking....

Anyone have comments or references to how it *should* be done? Will ICAT (Insulation Contact Air Tight) cans work with foam?

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Contact the manufacture of he light can. They should have information on this.

Well. Track lighting

Originally Posted by d ginther

IPlans call for recessed cans (4) to be installed in this area.
The roof rafters are 2x6 (5.5") - and the cans will obviously protrude into the area with foam insulation.

I can't find anything in terms of code that relates to foam insulation and IC (Insulation Contact) cans.

First, an IC rated can is, to my knowledge, tested such that the insulation type is not specific, otherwise it would be a nigh mare to manufacture, warehouse, stock, sell, and install IC rated recessed fixtures.

However, there are some other issues I see of concern, all of which may lead to design changes, making the IC rated recessed fixture in Icynene a moot point.

1) The 2x6 rafters, only being 5-1/2" in depth, may not leave adequate depth for the height of the recessed fixtures to be installed.

2) I would be concerned with the contact between the IC recessed fixture and the roof sheathing if within 3", although I suspect that is covered in the IC listing, may well have a zero clearance to combustible material.

3) Where the recessed fixture, IC rated or non-IC rated projects up into the insulation, the insulation will be non-existent, or, at a minimum reduced below the required R-value. There will effectively be 4 holes through the Icynene insulation.

Whether or not the 2x6 are all which is required for structural purposes, I suspect that going to 2x12 may well be required for proper insulation clearance above the recessed fixtures.

Another choice would be to use the 2x6 rafters, then fur down below that to a depth which will allow the recessed fixtures to not intrude into the required R-value depth of the insulation. This will also make wiring easier, and adding future circuits easier, as there is not a furred down space through which things can go, no need to drill through the rafters now.

Nice track lighting.

Hate to be short winded on the matter but the added expense as Jerry mentioned about building out framing of the entire ceiling will be quite costly. There is not enough room between the top of the can and the sheathing of the roof likery said.

Originally Posted by Ted Menelly

Nice track lighting.

Ted,

Some people simply do not like track lighting and would prefer recessed fixtures.

*I* am one of them.

Yes, it does depend on the cost involved, but at this stage of construction, furring down the ceiling is not going to cost *that much more*, and it will give a lot more flexibility to change things in the future by having that furred down space.

Granted, though, depending on the design of the house, there may be a headroom problem, but, with a vaulted ceiling, that is highly unlikely. The ceiling could start at the already planned height at the walls, then drop down at the ridge, making sure to allow more than enough room for the recessed fixtures at their proposed locations.

Granted, it will not be like our house here with 14 feet to the peak of the vaulted cathedral ceiling, and then there is another 7' to 8' above it in the attic, but it will still allow for changes and repairs, fishing wire, plumbing, duct work, etc., at any point in the future.

In fact, it will make running the to-be-installed (if not already installed) duct work easier to install, and offer more versatility in where it is possible to locate supplies and returns.

Simply put, it offers MANY advantages.

One of the things I was also thinking about was if they foam the underside of the roof and then leave a space between the drywall and the foam there is more to worry about as well like moisture concerns and things like that. Drywall, air space foam, hot or cold roof, hot or cold drywall. Ventilation will have to come into play as well. I have just so often seen concerns later with can lights in that situation with added foam sealing things up against a roof. I guess I would have to put the brain cells together to give better advise. Its been a while since I played builder.

Why not install LED lights? Long life (50k hours), very low energy consumption, very low heat output, and I think the can is a maximum of 4" in depth or less.

Changing the lights is an option. I'm needing some grounds to make that change - otherwise "choice" deviations from plan (and bids) incur time and financial penalities. I like the LED option myself, although these probably require a transformer and low voltage wiring (which would be OK).
I can't go to 2x12 rafters realistically - the house is already framed. I'm in Texas (no snow loads) and 2x12 rafters are structural and financial overkill.


Again, being in Texas I'm only aware of "recommended" insulation values (which are huge). I'm not sure that specific R values are required by building code. Also, traditional R values don't exactly apply 1:1 for foam.
We're spending a lot of money (300% of a traditional batt insulation budget) so we really don't want to hollow out the foam to fit a recessed can.


The question sorta remains - I don't hear anything in a building or electrical code preventing me from setting IC contact cans directly on foam insulation. It sounds like I'm left to contact the manufacturer of the recessed can. I believe the cans that are spec'd are "short" depth - so they don't protrude all the way down.
I also like the fur down option, but LEDs or track lighting would be easier.

what specific building, mechanical, and energy code are you building to?
Your design load is based on the U value of the building envelope not R value of a component.

Originally Posted by Richard Pultar

what specific building, mechanical, and energy code are you building to?
Your design load is based on the U value of the building envelope not R value of a component.

Which code we're adhering to is somewhat open for discussion. We're in an unincorporated area and Texas just started requiring inspections for registered builders in unincorporated areas.

I know that for electrical, my nearest locality requires that we build to the 2005 version of th NEC. Because we're not in the city there is ongoing litigation trying to determine which version of which code builders have to adhere to. Per the county attorney, the builder is required to adhere to the 2008 NEC. Mechanical / Energy code - to be honest, I'm not sure.

I'd call the building department and ask for a partial or courtesy inspection. You paid for a permit and you want to be assured that what you are getting is ok.
It will give the guy something to do. If something is wrong you fix , if it's ok you can think about other stuff.
Some people hate inspectors and some people appreciate the input. As long as the guys not a nut you should be alright. It's a chance you take but I would take it.

I have recessed lighting and have switched to florescent lamps. The draw back for me is that they are slow to achieve max output, more so when it is cold. Once warmed up they are very close to incandescent in the lumen output.

I don't think you have any problem with the foam and the IC type light cans. I can't tell you much about the headroom issue without seeing the framing, but it's pretty straightforward if you're using light cans. You need enough space to fit the can into the area. Make sure that they spray around the cans.

My friend is a GC and we were just talking about the use of the spray in foam. He said it sells as a great product, but if you go back and look after the insulators are finished, there are lots of air gaps around penetrations, wiring, light cans, etc. This is exactly the spots that you would think it would pay off to use the foam. They went back in behind them with Great Stuff and sealed a lot of areas.

The main problem he thought was that it came out of the nozzle so fast that the installers didn't have time to work it into some of the smaller areas. Other installers may be better, but keep your eyes open. After it's sheetrocked there isn't a whole lot you can do about it.

From the TRRC and the Texas Legislation: (B) for residential construction located in an unincorporated area not in the extraterritorial jurisdiction of a municipality, the version of the NEC applicable to electrical aspects of residential construction in the municipality that is the county seat of the county in which the construction is located and which is effective on the date of commencement of construction of the home; and

(C) for residential construction located in an unincorporated area in a county that does not contain an incorporated area, the version of the NEC that existed on May 1, 2001.

(8) The International Residential Code (IRC)--substantial compliance with the non-electrical standards contained in the version of the IRC for One- and Two-Family Dwellings published by the International Code Council (ICC) as follows:

(A) for residential construction located in a municipality or the extraterritorial jurisdiction of a municipality, the version of the IRC applicable to non-electrical aspects of residential construction in the municipality under Local Government Code §214.212 and which is effective on the date of commencement of construction of the home;

(B) for residential construction located in an unincorporated area not in the extraterritorial jurisdiction of a municipality, the version of the IRC applicable to non-electrical aspects of residential construction in the municipality that is the county seat of the county in which the construction is located and which is effective on the date of commencement of construction of the home; and

(C) for residential construction located in an unincorporated area in a county that does not contain an incorporated area, the version of the IRC that existed on May 1, 2001.

Whether you are in an incorporated area or not. The entire State of Texas has adopted the IRC-2000 version.

Yes, I know that it is 'older' and many AHJ's are using IRC-2006 as well as NEC-2008.

The builders 'out in the county' may not even realize that they are "supposed to" be building under the IRC-2000. I encounter and have encountered that many, many times over the past number of years.

The TRCC requirement (as of this past fall) for the phase inspections has just brought reality home.

Nolan, from what I understand, the prevailing code would be that of the municipality of the county seat (i.e. McKinney for Collin county) unless the county does not have a municipal code in which case it reverts to the state code.
Am I reading this right?

Jim,

Yes. If (for example) McKinney has adopted 2006 IRC and 2008 NEC, etc., etc. that is what is the guide for their span of authority.

If (for example) Dime Box, TX (Yes ... it does exist) does not have a defined AHJ, etc., all residential construction defaults to the State of Texas accepted standards which are currently the 2000 IRC.

BTW - no disrespect intended to Dime Box, TX.

Originally Posted by Nolan Kienitz

If (for example) Dime Box, TX (Yes ... it does exist) does not have a defined AHJ, etc., all residential construction defaults to the State of Texas accepted standards which are currently the 2000 IRC.

Nolan,

Is Dime Box, TX the county seat?

If not, then what is the county seat and what code do they have?

That is what Jim asked and you said yes to, so I am just clarifying it:

Nolan, from what I understand, the prevailing code would be that of the municipality of the county seat (i.e. McKinney for Collin county) unless the county does not have a municipal code in which case it reverts to the state code.
Am I reading this right?

EC Jerry,

Don't know if Dime Box is the country seat or not, but you are correct as is Jim ... it would/should default to the 'standards' adopted by the county seat.

Didn't mean to muddy the clarification ... but I had to get Dime Box in there

Personally, I have always liked the town called No Trees, Texas. What a great name. Well, there are some trees there now, if you call a 7 foot Mesquite a tree.

Bill

I'm actually in Travis County (near Austin). We're unincorporated, but technically within an extraterritorial jurisdiction of Lago Vista.

Lago Vista does not and will not inspect or permit homes within it's ETJ.

The county seat, is, of course Austin.. And I believe Austin subscribes to the 2005 NEC.

Apparently there is pending litigation on the issue of NEC and unincorporated areas, we've been advised by counsel that we need to adhere to the 2008 NEC - which is significantly more painful to my wallet.

I have an EE degree and some of the changes 2005-2008 simply make marginal (if that) sense to me... Regardless.

The cans in the vaulted ceiling area were completely pulled. Per foam insulation insdustry best practices, they're having foam installers build drywall boxes around IC light cans, which would have put big insulation holes in my ceiling.. Some are suggesting the use of fiberglass to also distance the foam from the cans. It seems that most inspectors can't address these issues in my area - foam is too new and at a cost of 300% compared to bat insulation, it's not going into a lot of houses...