When mechanical equipment is in the attic...

When there’s mechanical equipment located in the attic space, it shouldn’t be further than _____ feet from the attic access.

What’s your answer? (Don’t look it up! Anybody can do that. Take a guess.)

20 feet

When did the 20’ rule take effect? Had a 1990 home that had equipment at least 40’ away. It was called out.

I had no idea there was a footage rule for mechanical systems in the attic, as long as there’s access. Let me guess…10 feet?


I’m in the middle of taking the advanced HVAC course, the answer is 20’. I did not know this before. Can anyone tell me why 20’? Why does it matter?

20 feet. UNLESS there is adequate headroom, then it is more. I can’t remember the headroom requirement but I believe the minimum is either 6 feet or 6 feet 6 inches because I can stand up.

I hate attic installations, especially in the summertime. Nothing worse than a 150 degree attic, furnace installation at the far end and a sheet metal cover on the work platform. :mad:

There must be a “passageway” at least 30 inches high and 22 inches wide and not more than 20 feet in length. Decking in front of the HVAC equipment must be at least 30x30 inches.

I call it out when there is no decking on the passageway.

0 feet from the attic access.

The Mechanical equipment should be made accessible from the attic access panel area or a catwalk provided to reach the area of the equipment, along with light switch and light and a service receptacle.

Am I close.??:mrgreen:

You’re 20 feet too close.

Well then, looks like you need to build me a catwalk to get there. :mrgreen:


Well, since you peeked and were not supposed too!

**Question: **[FONT=Arial,Arial][size=3]If a furnace or air-handling unit is installed in the space above a lay-in or drop-in ceiling, does Section M1305.1.3 “Attic Furnace” apply? [/size][/FONT]

**Section 1305.1.3 requires
**[FONT=Arial,Arial][size=3]a catwalk, access, work platform, electric outlet and light. The context of this provision of the IRC indicates that this section of the code refers to an attic space which is an area created between a [/size][/FONT][FONT=Arial,Arial][size=3]permanent ceiling [/size][/FONT][FONT=Arial,Arial][size=3]and the roof of the structure, not a space above a drop in ceiling. [/size][/FONT]
[size=3][FONT=Arial,Arial]Additionally, note the exception in Section 1303.1.3 of the IRC that states:
[/size][/FONT][FONT=Arial,Arial][size=3]Exception: A working platform need not be provided when the furnace can be serviced from the required access opening. [/size][/FONT]
[FONT=Arial,Arial][size=3]The furnace or air-handler may be accessed through the lay-in or drop-in ceiling and the supporting grid assembly. The grid is not part of the permanent structure and may be easily removed for servicing or for the removal of the equipment.
Therefore, air-handling equipment installed in the area between a lay-in or drop in ceiling and upper floor or roof assemblies need not comply with Section 1303.1.3. [/size][/FONT]

I just want to make a point here;

First of all, we are not Code Enforcement Officers (C0E) and the limitation of a 20 long walkway is based on the written fact that the minimum height is only 30” high.
A little common sense here has to be applied.

First, if this is an old house, there will be no catwalk. Watch your step. :slight_smile:
If this is a new House that applies to the IRC, well fine, if you want to enforce the code, go right ahead.

The mechanical equipment is either going to be readily accessible or it is not.
At 30” high, having to crawl more than 20’ would not be readily accessible.
Damn, I don’t think I could make it that far. :wink:

Most of the framing in attics is 24” on center, now to me that leaves 22&1/2” in between the framing, so 22” catwalk would not be economically feasibly to me if I were to frame it.

All I am trying to point out, is that these codes are minimum requirements and a little common sense should be used in calling out stuff. The codes will not apply to every individual variable out there.

I have had catwalks that are over 300 ft. long. But I could stand up and walk, and they were 24” wide not 22”.

Further more, if a Mechanical Contractor wants to install his equipment 20’ away from the access point at 30" clearance, he is crazy. :slight_smile:

Marcel, I’m inclined to agree. I’m not a stickler on the 20 foot rule and have never called that out. I do, however, call out the absence of a decked passageway and the absence of an adequate deck in front of the equipment. I also call out the absence of a light and outlet near the equipment (in attics and crawls).

I’ve seen furnaces jammed in trusses so tight a midget couldn’t get to it to work on it properly. I realize me calling out an ‘inaccessible’ furnace won’t change anything. But at least the buyer is made aware.

I agree, if I can’t get to it safely and without crampping out, I call it out also. :slight_smile:

I can’t count the times I’ve inspected attic units while balancing on ceiling joists.

Flooring in attic is definitely in my report.

If there is not walk to the HVAC or other parts of the attic, I don’t inspect it (the code is the justification as to why).

Just like crawlspace access. It is a violation of OSHA Confined Space.

OSHA doesn’t apply to you, David. And, just curious…how does the lack of a catwalk bring OSHA’s rule into play at all?

Violation, smiolation.

I complete all my home inspections as long as I’m capable of getting there. I do not allow a simple balancing act spoil my thoroughness of a home inspection. I’ve never fell through an attic and I do not plan on falling through an attic anytime soon. Ceiling joists are quite easy to locate when insulation can be kicked around. And that’s what I do.

I can see it now…Sorry Mr. Client, I can not and will not inspect your 26 year old attic HVAC system, because there is no adequate catwalk flooring to the unit. Because this is unsafe, I recommend you have this corrected and I’ll return for an additional fee to re-inspect.

That’s BS and (IMHO) very lazy.