Electrical boxes

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Eagle126

Member
I live in massachusetts, someone told me that starting this year all electrical boxes on the outside walls of a residential home must must a gasket around the outside of the box for the prevention of air flow, has anyone heard of this? Is this in the national code, or mass code?
 

kwired

Electron manager
Location
NE Nebraska
I understand the principle of reducing air flow but almost all new construction is done in a way that makes this unnecessary IMO. They seal bored holes for cables and often spray foam on the interior side of sheathing for better sealing of any holes, cracks etc. Where is any air infiltration going to come from to enter around a switch or receptacle box ? If you have an exterior receptacle it is sealed off by the spray foam also, unless it is not cut in before the spray foam was applied.
 

tkb

Senior Member
Location
MA
I just took our code update course a couple of months ago and don't remember hearing about this.
 

Steviechia2

Senior Member
Location
Massachusetts
I seen the boxes with the rubber gasket set back 1/4 of an inch at a job I inspected last month. I meant to ask the building inspector about this. I will ask about this next week
 

Eagle126

Member
Exactly what i am talking about, i saw the same boxes at the supply store 2 weeks ago, i will also look into this a little further. If anyone else has seen or has installed these boxes i would like your advice or input. thanks again.
 

dwellselectric

Inactive, Email Never Verified
I ran into this for the first time today. However I see it being an issue somewhat. The building inspector had the contractor fill the holes being used in the boxes with hole filler. Yeah well as you can guess alot of the filler got into the boxes and it is somewhat a pain to dig the wires out. My question is so they want all the holes filled that are in use. What do you do about low voltage boxes? Do you fill the wall :lol:
 

kwired

Electron manager
Location
NE Nebraska
I ran into this for the first time today. However I see it being an issue somewhat. The building inspector had the contractor fill the holes being used in the boxes with hole filler. Yeah well as you can guess alot of the filler got into the boxes and it is somewhat a pain to dig the wires out. My question is so they want all the holes filled that are in use. What do you do about low voltage boxes? Do you fill the wall :lol:

Have them fill building inspectors mouth with the foam filler while they are filling holes. Filling holes where cables run through framing members as well as any other holes is sufficient to stop drafting through the box.
 

George Stolz

Moderator
Staff member
Location
Windsor, CO NEC: 2017
Occupation
Service Manager
I recently witnessed a GC that had to literally suck all the insulation out of the attic of a new apartment, seal every penetration again they could spot, caulk every crevice they could think of or find, to bring their CFM down from 1700 to the required 500. You can bet they'd wished they'd foamed every hole they could see before the drywall went up. :eek:
 

kwired

Electron manager
Location
NE Nebraska
I recently witnessed a GC that had to literally suck all the insulation out of the attic of a new apartment, seal every penetration again they could spot, caulk every crevice they could think of or find, to bring their CFM down from 1700 to the required 500. You can bet they'd wished they'd foamed every hole they could see before the drywall went up. :eek:

Some people need to learn things the hard way.

I could never fully understand making a building so air tight, then turn around and install fresh air ventilation systems. Spending more money to accomplish the same thing. Conditioning the air before bringing it in does not matter. Same temperature of air is coming in and needs conditioned eventually.
 

M. D.

Senior Member
It is commonly referred to as the Stretch code.. as it is now it is an opt in thing but I'm told it will be state wide next year...
http://www.cityofboston.gov/Images_Documents/EOEEA q_and_a_stretch_code_tcm3-21504.pdf


"5. What is the anticipated cost of the stretch
code?
Construction costs are estimated to rise approx-
imately $3,000 for a typical single family home,...."
So the market cost will be higher and less people will be able to afford to buy .. or lending will get stupid again
 

M. D.

Senior Member
Here is another link with a map ,.. it is 7 months old so maybe more towns/cities
have accepted it . I was told that the HERS inspection can cost as much as $1,000 to $1,500.. I have no idea of the validity of that cost .. just something I heard at the job site

http://gordonharris.blogspot.com/2011/01/massachusetts-stretch-energy-code.html

"independent certification by a HERS rater. Submission of a copy of the HERS report, a completed Energy Star Thermal Bypass checklist, and posting the relevant energy data on the electrical panel in the home are required and must be submitted to the local building inspector prior to receiving a certificate of occupancy."
 

renosteinke

Senior Member
Location
NE Arkansas
"Not an NEC rule" What's your point? I bet it's not in the Fish & Game regulations either.

We're not limited to complying with only the NEC. I weary of this 'tunnel vision' where electricians pretend that the NEC is the only code. It's not, and we get to comply with ALL codes. When we get our Masters' we are expected to do design work as well - and then we can't pass the buck to the 'stupid architect.'

I recommend watching "Holmes on Homes." Many are the episodes where they expose electrical work that was otherwise done in a competent manner- but the sparky completely ruined the "membrane" when he installed his boxes.

Think about that the next time you are asked to add a few pot lights to a kitchen. How many here even know what 'tuck tape' is, let alone have a roll on the truck? How many have used any form of putty pad ot ductseal to seal the backsides of boxes for air infiltration?
 

iwire

Moderator
Staff member
Location
Massachusetts
"Not an NEC rule" What's your point?

Why must you always make a big deal about this?

I think the point is that he is asking the question at an NEC training website in the Forum specifically titled "NEC" so he was just suggesting to expand the horizons.

As much as many, many other codes effect our work this site is for the most part about the NEC.
 

Bigrig

Member
Location
Dayton, OH
I could never fully understand making a building so air tight, then turn around and install fresh air ventilation systems. Spending more money to accomplish the same thing. Conditioning the air before bringing it in does not matter. Same temperature of air is coming in and needs conditioned eventually.

There are several reasons to air-seal walls. With a HRV/ERV much of the energy used to condition the air can be recovered. The idea is to only bring in as much outside air as required, something you cannot control through natural air exchange. It is also to prevent moisture problems within the walls. Water in warm, moist air filtering through a wall can condense in the walls. Then you get mold/rot.
 

kwired

Electron manager
Location
NE Nebraska
There are several reasons to air-seal walls. With a HRV/ERV much of the energy used to condition the air can be recovered. The idea is to only bring in as much outside air as required, something you cannot control through natural air exchange. It is also to prevent moisture problems within the walls. Water in warm, moist air filtering through a wall can condense in the walls. Then you get mold/rot.


How many ERV's fail and never get repaired? Like anything else mechanical they are going to fail at some time.
 
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