Insulation Code Changes (Proposed changes)

Cosmo_3 · August 2006

[Deleted User] · August 2006

As proposed by Guy McMann, CBO Jefferson County Colorado

Greetings Wallies,

My associate with the Jefferson County Building department here in Colorado would like to view your opinions on his proposed code changes regarding the requirement of thermal insulation in radiant heating systems. His proposed changes area as follows:

Proposal: Add new text as follows.

1209.5 Thermal barrier required. Radiant floor heating systems shall be provided with a thermal barrier in accordance with 1209.5.1, through 1209.5.4

1209.5.1 Radiant piping utilized in slab on grade applications shall be provided with insulating materials installed beneath the piping having a minimum r-value of 5.

1209.5.2 In suspended floor applications, insulation shall be installed in the joist bay cavity serving the heating space above and shall consist of materials having a minimum r-value of 19.

1209.5.3 A thermal break shall be provided consisting of asphalt expansion joint materials or similar insulating materials at a point where a heated slab meets a stem wall or other conductive slab.

1209.5.4 Insulating materials utilized in thermal barriers shall be identified in accordance with section 102.5.1 of the International Energy Conservation Code.

Note: Show the proposal using strikeout, underline format. At the beginning of each section, one of the following instruction lines are also needed:
Revise as follows
Add new text as follows
Delete and substitute as follows
Delete without substitution

Supporting Information (3.3.4 & 3.4): Many tens of thousands can be spent on radiant heat systems that do not work properly due to the lack of thermal barriers. Theres not much inspectors can do when they see piping laying in the dirt with no insulation beneath it. Radiant systems cannot operate as intended without a thermal barrier.
In the case of a slab on grade application, the ground will require a substantial charging of energy in order to hit a point of equilibrium where the thermal energy starts coming upwards instead of going downwards. Thermal energy flows from hot to cold, always and continuously. It substantially effects the over-all energy requirements and can seriously affect the performance of the system negatively and waste precious resources.
In the case of a suspended floor application, if the insulation is not properly applied, the lower floor (basement) will have a tendency to overheat and the floor that is trying to be heated will be under-heated. Once the system is installed without insulation its too late and balancing is virtually impossible. The end result is that energy bills are high, comfort levels are low due to the lack of insulation, which in most cases can not be retrofitted to appease the situation. The lack of insulation can drive the operating costs as high as 25% depending upon the application and exposure. The paybacks for the consumer are huge considering the minimal cost of insulating materials such as 1-inch foam, which costs approximately .48/sq. ft. The energy code does not provide guidance in this situation. It is appropriate for this text to be included in this document as this is what is used by installers for the installation.

Note: The following items are required to be included:
Purpose: The proponent shall clearly state the purpose of the proposed code change (e.g., clarify the Code; revise outdated material; substitute new or revised material for current provision of the Code; add new requirements to the Code; delete current requirements, etc.)
Reasons: The proponent shall justify changing the current code provisions, stating why the proposal is superior to the current provisions of the Code. Proposals that add or delete requirements shall be supported by a logical explanation which clearly shows why the current Code provisions are inadequate or overly restrictive, specifies the shortcomings of the current Code provisions and explains how such proposals will improve the Code.
Substantiation: The proponent shall substantiate the proposed code change based on technical information and substantiation. Substantiation provided which is reviewed in accordance with Section 4.2 and determined as not germane to the technical issues addressed in the proposed code change shall be identified as such. The proponent shall be notified that the proposal is considered an incomplete proposal in accordance with Section 4.3, and the proposal shall be held until the deficiencies are corrected. The proponent shall have the right to appeal this action in accordance with the policy of the ICC Board. The burden of providing substantiating material lies with the proponent of the code change proposal. A minimum of two copies of all substantiating information shall be submitted. (3.4)
Bibliography: The proponent shall submit a bibliography of any substantiating material submitted with the code change proposal. The bibliography shall be published with the code change and the proponent shall make the substantiating materials available for review at the appropriate ICC office and during the public hearing.
Referenced Standards (3.4 & 3.6):

List any new referenced standards that are proposed to be referenced in the code and provide a minimum of two copies. For ICC rules on referenced standards, see Section 3.6 of CP #28.
Cost Impact (3.3.4.6): Will increase cost.

Note: The proponent shall indicate one of the following regarding the cost impact of the code change proposal:
1) The code change proposal will increase the cost of construction; or
2) The code change proposal will increase the cost of construction.
This information will be included in the published code change proposal.

END OF PROPOSED CHANGES.

What thinks ye wallies? Any and all comments are appreciated. He has a very short time in which to prepare his final recommendations and wants to make sure that it is right the first time before submittal.

Thank you in advance for your comments, pro or con.

Bear in mind for our friends to the FAR north (Weezbo et al), that these are MINIMUM insulation standards. As the code usually dictates, local code enforcement can be equal to or greater than, but not less than the precriptive code.

Thanks in advance. I am going to invite Mr McMann to visit this site frequently to view your comments.

ME

Brad White_111 · August 2006

With all due deference to those

who write the codes, here are a couple of modest suggestions:

1) In general, the R value stipulated should be proportional or relatively so to the Delta-T encountered.

2) 1209.5.3 A thermal break shall be provided consisting of asphalt expansion joint materials or similar insulating materials at a point where a heated slab meets a stem wall or other conductive slab.

Here is where I would state a definite R value. Just any thermal break can be construed to have an R value greater than the adjacent material. I would vote R-5 minimum at any perimeter where against a conductive wall. R-10 would be my performance ideal if the detailing could be worked out. This to me is the largest loss. The earth may eventually come to equilibrium but the air is so volatile it just sucks the heat away; so if you are insulating the under-slab to R5, why not the perimeter to at least that?

Perhaps they could allow the nominal thermal break (joint filler) if it can be demonstrated that the exterior of the concrete vertical wall is also insulated to a given degree (R5, R10 if you can.) Nothing wrong with the joint filler in addition, I just do not call that insulation.

1209.5.2 In suspended floor applications, insulation shall be installed in the joist bay cavity serving the heating space above and shall consist of materials having a minimum r-value of 19.

In this paragraph, is there some wiggle room such as including or not including an air space or a radiant reflective barrier? (We all know how they dust over, but still....)

Further thoughts: I hope the materials approved are real bona-fide R-values, not the "bubble-wrap is good" BS. Do they have well-defined and enforcable standards I guess I am asking. Does bubble wrap with all of those labels still have any credibility?

Anyway, my $0.02.

The person here in MA who chaired the Energy Conservation Committee for the Massachusetts State Building Code is a good friend of mine, so my appreciation for the work that goes into this is strong.

Christian Egli_2 · August 2006

Looking for loopholes, but I'm no lawyer

For installs involving a gypcrete type of pour over the floor but with insulation added in between, perhaps a separate paragraph is appropriate. It is neither below grade nor between joists.

Also, the important expansion joints in poured systems should be related to the slab size, if that's manageable.

Just loose thoughts

Larry Weingarten · August 2006

At some point...

... someone is going to ask why it is important to have nearly four times as much insulation under a suspended floor than called for under a slab. So, I'll ask ;~)

Yours, Larry

Brad White_111 · August 2006

My understanding

is that in addition to driving heat upward where you want it, it minimizes downward heat to where you do not; prevents a radiant ceiling at the floor below. I think it is a "standard" and for that reason alone, worth challenging it- I for one am glad you did.

[Deleted User] · August 2006

Delta T = driving force

Larry, the delta T below a staple up or suspended system is much greater than the delta T between a slab and the ground below it, hence a higher R value. Remember, this is MINIMUM standard. If the designer/architect/contractor desides to go with R 20 foam below their slab, than so be it. It meets the minimum standard.

At present, there is NO requirement for insulation below a RFH panel, unless said floor is over an unheated crawl space...

I for one am tired of the constant complaint from mega million dolar home owners telling me they can't get their main floor rooms above 60 degrees F, and oh by the way, the basement won't cool down below 85 degrees F and do we do air conditioning...

Or, the other regular complaint whereby the boiler ran for 30 days straight heating the basement, and it was in the middle of the summer!!

Time for a change, and this in my opinion is a move in the right direction. Is it the "perfect" answer. No, it wasn't meant to be perfect for every application. IF a person has an "engineered" system, i.e. the earth link was taken into consideration in the design, then it could be exempted at a local level from this aspect of the code as it pertains to the core insulation requirements.

IMHO, a minimum standard would go a long ways toward helping this industry. At present, due to the lack of a minimum insulation standard, the industry is being hurt by the bad mouthing of RFH from customers who DON'T have ANY insulation where it should be.

Please, continue the conversation and thanks in advance for your valid input.

ME

Ron Schroeder · August 2006

Larry

Both Brad and Mark are right but let me try to put it in another way, in slabs your heating the slab and just need to make it easier for the heat to go up rather than down, same in staple up but now now we have an insulating medium on top the wood, carpet etc and now inorder to drive the haet up we must overcome that insulating factor. So the tighter and higher the R value the more heat will traansfer up not down or out the sides.

Bruce

Weezbo · August 2006

i like insulation.

under slab i would like to see even thicker than R-10 .that might slow radiant downward loss and increase the lateral direction,,,i think the heat would be wanting to go to the plattes of walls and partitions...so sound insulation would be a good thing also plus that might tend to stop losses into the wall and thru the framing and out the plates into the trusses...

Eric_25 · August 2006

Brad - ? the reflective barrier

You mention the reflective barrier below tubing, I have been involved in this debate for years with others regarding the refecting of radiant heat. I was taught years ago that you can not reflect radiant heat, I heard this from Wirsbo and from ME's a lot smarter than me ( I think, or so they claim). What is the opinion today? Has it changed in the last 15 years since I took classes on installing radiant systems?
Next subject - I have found that R-5 is more than adequate on in-slab installs on two different jobs we installed probes under the R-5 Dowboard or it may have been R-6 and found no difference in the ground temp. directly below the Dowboard and 12" below the Dowboard. The most important insulation is the thermal break from the slab to the outside walls and the 8' perimeter of the slab.

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Brad White_9 · August 2006

Reflections...

Eric, Hi.

Radiant heat by definition can be reflected, any radiation can. The key is that the foil-faced "reflectors" dust-over after not long a time (as was demonstrated here some time ago). Hence the effect is short-lived. A thin coating of dust kills the emissivity. I still see value in foil in that it helps seal the airspace, defines it and allows the temperature to spread for more even coverage at the floor level. This as opposed to squishing it all up against the tubes. Plates of course, rock.

We agree on the thermal break between slab edge and wall. The delta-T you measured is very helpful to know. I consider R-5 a minimum and it is code here in MA. R-10 at perimeters I think is worth it especially when above grade. But R-5 is code minimum there too.

Cosmo_3 · August 2006

we need this

I am sick and tired of listening to builders complain about my adamant refusal to use the tarps, bubbles, and barriers on every job.

There should be a standard that we have to follow based on R-value. I think that most inspectors still do not know how important the moisture barrier is. I can no longer count how many times I was about to start laying out tubing when I noticed the concrete guys didn't bother putting down a poly sheet before the foam. There is a reason the concrete guy does the insulating for a better price, 9 out of 10 times he doesn't care.

Lets just say bare minimum on residential work should be 2" foam under, at least 1" perimeter. 2" perimeter better.

Good thread ME, how are ya buddy

Cosmo

Insulation Code Changes (Proposed changes)

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