Re: New Home Construction

["Robert L Bass" <robertlbass@xxxxxxxxxxx>]

>> Fishing wire in a US stick-built house is not as
>> hard as it would seem. So running everything
>> in conduit is probably not worth it. But do make
>> a conduit/chase from the basement to the attic
>> so (assuming a 2-story house with basement and
>> attic), you can get to the first floor rooms from
>> the basement and the second floor from the
>> attic.

Agreed.  Even retrofitting a multistory home is usually not difficult if the
construction is standard "platform" (aka "Western") framing.  When
installing an alarm or home automation system keypads and/or inside siren on
a second floor you can use the wall opening as a reach-in point to drill
down from one floor to the next.  This is a convenient way to create a
wiring chase from attic to basement if you select a location on the main
load bearing wall.

> I'll second this recommendation and note that the
> riser should be as large as you can accomodate.
> A 4" conduit would be good.  I ran a 3" and filled
> it much quicker than expected.  Either a larger
> one or a pair of them would be a VERY good idea.

Also agreed.  I prefer to run two or more conduits.  One is for 110/220 Volt
cables.  A 2" run should be sufficient for small to mid-size homes.  Go with
3" if the home is over 3000 SF.  Another run is for alarm/automation
cabling.  Check the manufacturer's instructions *before* you install the
conduit.  Some systems don't allow the keypad and expansion device cables to
be run in the same conduit as sensor (zone) wiring.  A third run should be
included for future audio/video cabling.  These services should generally be
kept clear of alarm/automation cables as well as 110/220VAC cables.

> As Marc points out it's really not all that hard to
> fish a wire up/down a wall in most modern US
> homes.  The wall cavities are generally pretty easy
> to get through.

Outside walls in modern homes are usually filled with Fiberglas insulation.
It's easy to get past the stuff without binding up the drill bit if you
wiggle the shaft around a bit before drilling through the bottom plate to
the basement.  INside walls, other than those surrounding the bathrooms, are
usually uninsulated so they're even easier to fish.

When installing mud rings in hollow walls, I like to tape a dental mirror to
the side of a Maglight flashlight.  This allows me to view the inside of the
wall cavity.  Also, when installing anything in a second floor wall you can
stick the Maglight in the hole and leave it on while you go to the attic.
Drill down through the top of the wall using a 3/4" paddle bit (aka "spade
bit" or "speed bore").  If you can see the light inside the hole you're in
the right place.

> Putting a hard conduit in the room itself locks
> you into running the wires to THAT location.
> As in, if you put it down at outlet level you're
> screwed for entrance area keypads.  Likewise,
> if you just ran it to the entrance area keypad
> you'd be stuck for PC, telco or ethernet hookups.
>  Granted, you can generally be sure that
> something setup near the door will always be
> 'useful' but it's hard to predict where on the
> other walls you'd want things placed.

Furthermore, it may be handy to run conduit to junction boxes for certain
applications, but I prefer to use mud rings for low voltage work.  These
make it much easier to fit box-filling devices like volume controls and
heavilt populated multi-service outlet plates without jamming the cables
into a tight box -- a major no-no for data cabling.

> For 1st floor rooms if you can get to the floor
> below via the space in the joists you're set.  For
> 2nd floor rooms you can usually go up to the attic
> space.  But if you've got spaces that aren't going
> to be accessible then some creativity is in order.
> Either by simply knowing the 'run' of the joists
> (front/back or right/left) or having access panels
> installed in places that will be known trouble
> spots.  As in, the closet under the stairs...

Under-stair closets make handy places to run alarm cabling, especially in
the "raised ranch" homes popular in southern New England.  Another place
that can be useful for retrofitting cable is the "wet wall" (plumbing chase)
to a second floor bathroom.  On older homes things can be more complicated,
but there is almost always a place where you can pull cables from level to
level.

> If you really know how the rooms will be used the
> most difficult thing to wire is ceiling speakers...

Here's a handy method I've used on hundreds of first floor ceiling speaker
installations over the years.  Place the speakers within a foot or two of an
inside bearing wall.  The joists will almost invariably run perpendicular to
the bearing wall.  The cutout for 8" diameter speakers will easily
accomodate your forearm and a right-angle cordless drill (available at HD or
www.coastaltools.com).  Using a 3/4" paddle bit, drill down into the top of
the bearing wall.  Drop enough cable in the wall to go about 2' past the
floor level.  Measure the horizontal distance from the cable drop to a
nearby outlet or side wall.  In the basement measure the distance over from
the nearby wall or the 110VAC cable supplying the outlet and drill up into
the wall with the paddle bit.  You can easily reach into the wall cavity
with a fish tape or bent coat hanger to pull the cable down to the basement.
Have someone on the mail level feed the speaker wire into the opening so it
doesn't mess up the sheetrock as you draw more out in the basement.

Another poster once expressed concern about using a paddle bit to drill
through a wall.  Note that this can easily and safely be accomplished if you
do the following.  Be sure you're standing on a firm surface -- not leaning
sideways off your ladder when drilling.  Drill at a moderate speed and do
not push on the drill.  Let the bit do the cutting.  When the bit starts to
come throuogh the other side of the wood it can bind if you're drilling at
an angle *and* pressing hard on the drill.  By using light pressure and
allowing the bit to do the job you will avoid problems.  Even if you do bind
the bit, unless you're using a really powerful drill you won't hurt
yourself.

> Having wire installed for them ahead of time, and
> fished to the entrance keypad area will save you a
> lot of trouble.  Most audio distribution systems
> these days suggest pulling the speaker wire to the
> keypad and then back to the central amp (when
> used).  This way you only run a single 4-conductor
> home run instead of two 2-conductor speaker wires.
> Just splice them in the keypad junction box
> (eurostyle terminal strips are good for this).

I prefer to do it slightly differently.  Run 14/4 from the amp to the volume
control location (preferably a single or double-gang mud ring).  Leave an
extra loop of 18-24" in the wall and continue the cable over to the
speakers.  Along with the speaker cable I like to pull a CAT5 cable and a
piece of 22/2, stranded, shielded cable for control and IR.  Leave 18-24" of
extra CAT5 at the volume control location so you can connect a control
system if you decide to use such at a later time.  Leave a similar service
loop in the shielded cable and continue it over to one of the wall or
cailing speaker locations.  It doesn't matter whether you go to the left or
right speaker but be consistent from room to room.  This will allow you to
install an IR receiver behind the grill of the speaker (really slick IMO).

> If you've not already hired one, seriously consider
> paying a local high-end audio shop for a placement
> plan for in-room speakers.  They generally have a
> bit more experience in the guess-work of placing
> them in the right locations.

On this I partly agree and partly disagree.  If you know the furniture
layout in advance it's easy to select stereo speaker locations for almost
any room.  If you're doing a home theater and the room is a complex shape,
go ahead and hire a pro to lay it out.  He might even give you a good price
on pre-wiring the place.

By the way, do NOT allow a hifi salesman to spec the cables.  Buy the cable
online or at an electrical supply house.  You'll end up spending a
"monstrous" amount of money on useless nonsense if you get it from most
stereo stores.

--

Regards,
Robert L Bass

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