Boring Sizes: Joists, Beams and Rafters (IRC 2006)

Started by manhattan42(Guest), April 09, 2006, 11:36:51 PM

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manhattan42(Guest)

Found this in another forum:
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INTERNATIONAL RESIDENTIAL CODE 2003 & 2006:

BORING OF JOISTS, BEAMS, AND RAFTERS AND PVC DWV PIPE SIZE

Section R502.8.1 Sawn Lumber subsection to R502.8 Drilling and Notching in solid lumber :

"The diameter of holes bored or cut into members shall not exceed one-third the depth of the member."

Lumber Size and Nominal Depth:
-------------------------------------
2x4 = 3 1/2" nominal depth
2x6 = 5 1/2" nominal depth
2x8 = 7 1/4" nominal depth
2x10 = 9 1/4" nominal depth
2x12 = 11 1/4" nominal depth

Maximum Bored Hole Size (D/3) R502.8.1
------------------------------------------------
2x4 = 1 3/16"
2x6 = 1 7/8"
2x8 = 2 3/8"
2x10 = 3 1/16"
2x12 = 3 3/4"

Outside Diameter of PVC Drain Pipes
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1 1/4" PVC = 1 11/16" OD
1 1/2" PVC = 1 7/8" OD
2" PVC = 2 3/8" OD
2 1/2" PVC = 2 7/8" OD
3" PVC = 3 1/2" OD
4" PVC = 4 1/2" OD

Approximate Bored Hole Sizes to Fit PVC Pipe in Dimensional Lumber
-------------------------------------------------------------------------------
1 1/4"PVC = 1 7/8"
1 1/2"PVC = 2"
2" PVC = 2 1/2"
2 1/2"PVC = 3"
3" PVC = 3 3/8"
4" PVC = 4 5/8"

Maximum Size PVC Pipe That can be Used in Dimensional Lumber (Joists, Rafters, Beams)
---------------------------------------------------------------------------------------------------------
2x4 = No PVC DWV Pipe. All PVC Exceeds D/3 boring limits
2x6 = 1 1/4" PVC only
2x8 = 1 1 /4", 1 1/2", & 2" PVC permitted
2x10 = 1 1/4",  1 1/2", 2", & 2 1/2" PVC only
2x12 = 1 1/4", 1 1/2", 2", 2 1/2" & 3" PVC only

4" PVC pipe cannot be bored through dimensional lumber at all under the IRC 2003 or 2006.


The problem is that designers, builders, and plumbers still think that boring for a 3" drain pipe is ok in 2x10 joists.

It is not.

You cannot even bore a hole for a 1 1/4" vent pipe through a joist, rafter or beam smaller than 2x6.

Okie_Bob

Great information Manhattan!! Thanks for all your posts, you are a great addition to this site!
Okie Bob