PDA

View Full Version : Wiring over fiberglass insulation



Jon mackay
02-15-2011, 02:32 PM
This is the first time I have come across this.

The wiring was installed over the insulation at many areas of the attic and was also pulled tight at a couple other areas.

I was looking for a reference to see how to report this..

Thank you

Scott Patterson
02-15-2011, 02:53 PM
This is the first time I have come across this.

The wiring was installed over the insulation at many areas of the attic and was also pulled tight at a couple other areas.

I was looking for a reference to see how to report this..

Thank you

Outside of a reduction in the R value due to the compression of the batts, I do not really see it as an issue. Now if the NM cable is so taut that it is pulling and might be damaged by something like nails or staples that are securing it then you have another problem. I think I would note exactly what you found and tell my client that it the R value has been reduced by an known amount. I would then tell them that I really have no idea if this is going to be a problem or not as I have never seen it done like this.

It never hurts to say "I don't know" if in fact you really do not know!

Jerry Peck
02-15-2011, 09:24 PM
While that NM cable may be "supported", it is not "secured": (underlining and bold are mine)
- 334.30 Securing and Supporting.
- - Nonmetallic-sheathed cable shall be supported and secured by staples, cable ties, straps, hangers, or similar fittings designed and installed so as not to damage the cable, at intervals not exceeding 1.4 m (4½ ft) and within 300 mm (12 in.) of every outlet box, junction box, cabinet, or fitting. Flat cables shall not be stapled on edge.

Jon mackay
02-16-2011, 05:51 AM
Thank you Jerry and Scott,

The wiring may be secured but I can't believe that it would be an acceptable installation just strapped over the insulation like that.

Also there were 2 attic hatches and one of them (which is needed due to a vaulted ceiling at the middle of the attic) was obstructed by something above, I would guess wiring.

It certainly begs the question of how they could have installed other wiring in the house if they had no problem wiring over the insulation and an access hatch.

William Kievit
02-16-2011, 07:01 AM
The wiring appears to be installed unprofessionally (DIY).
The entire electrical system should be evaluated by a licensed electrician.