Maximum Hole Size through Bottom Plate

mvdyk03August 22, 2007

I cannot for the life of me find the answer to this question. I am undertaking retrofitting/converting my first floor family room into a home theater room; to keep it "clean" all wiring will be "in wall" (coming "out") only at the wall-mounted TV, the wall-mounted speakers, and the A/V Rack.

The "video run" from the A/V rack to the TV presents somewhat of a problem since I need to run SEVERAL (component, composite, HDMI, coax, etc.) low voltage cables from my A/V rack to a box behind where the TV will be mounted. This will be accomplished by going down through the bottom plate in the wall behind the A/V rack, over in the basement (between the floor joists and the drop ceiling) and back up through the bottom plate of the wall behind the TV.

Now, here's the question. Since I'd like all of the wires to terminate in the one multi-gang box on each end, how big or how many holes can I put in the bottom plate of one construction bay (i.e. the space between two adjacent studs) before I need to worry about causing a structural integrity problem? Both of these walls are weight bearing, standard 2x4 construction.

Thanks in advance!!


Thank you for reporting this comment. Undo

Load bearing means that the wall is probably over double joists or similar support. Drilling them needs to be minimized. Drilling the smallest possible holes in the upper portion of the joists does minimal damage. Coax will fit easily in a 3/8" hole. Drilling at an angle so that the hole comes out on the side of the joists about 2" or 2 1/2" from the top should be OK. Typically, 4 such holes would be the most I would do without reinforcing the joists. I suggest getting a good framing carpenter to look in person and make suggestions. Can you go up or laterally? Can the holes be placed nearer a support for the joists? Limiting drilling to the upper third of the joist height remains important.

    Bookmark   August 22, 2007 at 2:22PM
Thank you for reporting this comment. Undo

I'm not sure I follow. I don't need to go through any joists since I'm going to run them laterally *under* the joists (but above the drop ceiling) in the basement. I'm really questioning how many (or how big) holes I can put in the bottom plate of the wall in which the cables will be run.

That is, here's the "run": (1) wall outlet box --> (2) vertical run down through stud/construction bay to base plate --> (3) through base plate --> (4) horizontal run down *under* floor joists but *above* drop ceiling in basement --> (5) through another base plate --> (6) vertical run up through another stud/construction bay --> (7) wall outlet box on other side of room.

How big can the holes for (3) and (5) be?



    Bookmark   August 22, 2007 at 4:26PM
Thank you for reporting this comment. Undo

I'll go out on a short limb for you as I do not know the 'official' answer since this is actually a building code question; not an electrical one.

However, assume you take worse case scenario and completely remove the whole bottom plate between the studs (e.g. essentially what happens when oval ductwork is installed, right?) Are you left with a significantly less structurally sound wall? Not likely as long as it isn't in the last cavity of the wall or you don't have to remove any lateral blocking. The vertical loads are transfered along the sole plate evenly into the floor underneath. Therefore, drill them as big as you want since anything less than the full width of the stud is still transfering the minute horizontal shear loads - just use strike plates as required.

    Bookmark   August 22, 2007 at 4:43PM
Thank you for reporting this comment. Undo

What is under the shoe "baseplate"? A load bearing wall sits on more than the subfloor. Lets head downward. Stud cavity, then the shoe plate, then the subfloor, then ?, then basement. What is between the subfloor and the basement directly under that wall? How was it determined that it is a load bearing wall?

    Bookmark   August 22, 2007 at 6:00PM
Sign Up to comment
More Discussions
Wiring in a 1 1/2" thick wall cavity
I need to run 12/2 wire thru an existing thin wall....
Wireless light switch for switched outlet?
So we have no overhead lighting in any of our bedrooms,...
Garage florescent light flickering - bulb or fixture problem?
I replaced the GE F40 RES garage lights with a GE F40...
bibbus 7b
Two fans on same circuit in different rooms, can't get wiring right
So here's the situation. I have two ceiling fan/lights...
Installing 220/240V. 50/60Hz appliances from Europe
I hope to install a "Domino" modular system...
Sponsored Products
Artemide | Mongura Table Lamp
Pink & Black Dot Ribbon Plate
$19.99 | zulily
Gemini Sr. Hand Truck Multicolor - GMK81UMB-1030 KD
$329.99 | Hayneedle
Single Lever Bath Shower Mixer with Square Spout and Pull-Out Hand Shower
Promenade Dining Side Chair in Gray
$79.00 | LexMod
Shower Curtain Artistic - Whale Mermaid
$89.00 | DiaNoche
Knoxville Pull Plate
Signature Hardware
Bayou Classic Outdoor Charcoal Starter
People viewed this after searching for:
© 2015 Houzz Inc. Houzz® The new way to design your home™