Dryer duct joint connection methods

[klarenbeek]

The dryer duct sections between the IMC, IFGC, IRC chapter 15 and IRC Chapter 24 is absolutely maddening because they are not the same. As stated above, IRC 1502 has 12' support intervals and joints mechanically fastened. There was a code cycle or two where the IMC was that way also but they at least fixed that one. The IFGC and IRC Chapter 24 have always had 4 foot intervals and secured in place and doesn't mentioned mechanically fastened except that you can't use screws or anything projecting in more than 1/8". We amended ours locally so they all said the same thing the IFGC and now the current IMC does.

 

[Inspector Gadget]

Because I'm *that* guy ..... Note temperature limits.

 

[Inspector Gift]

How many require nail plates under the IMC or IRC?

504.6.7 Protection required.

Protective shield plates shall be placed where nails or screws from finish or other work are likely to penetrate the clothes dryer exhaust duct. Shield plates shall be placed on the finished face of all framing members where there is less than 11/4 inches (32 mm) between the duct and the finished face of the framing member. Protective shield plates shall be constructed of steel, have a thickness of 0.062 inch (1.6 mm) and extend a minimum of 2 inches (51 mm) above sole plates and below top plates.

Every jurisdiction I've worked in the past 20 years requires nail plates for Dryer ducting where ducting is too close to face of framing.

 

[klarenbeek]

Because I'm *that* guy ..... Note temperature limits.

Shouldn't be an issue to use on residential dryer ducts for sealing. They get nowhere near 248 degrees. That's getting close to the temp of a water heater or 80% furnace vent.