How much weight will bottom chords of 2x4 trusses hold?

[k boeheim]

Our home is a 2 year old ranch. I am interested in running some speaker
wiring through the attic. Rear speakers will be ceiling mounted in middle of
room. my question is will the trusses hold me (220 lbs.)?

TIA

kb

[Harry]

Should be no problem. You may want to take a 3x3 piece of plywood to kneel
on while you work up there. Don't step on the ceiling -- you'll go right
through (you probably know that). And use a dustmask too.

Good luck.

H

"k boeheim" <kbo...@rochester.rr.com> wrote in message
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[Battleax]

walking in the attic, they certainly will support you. of course the
strapping and drywall between won't, but keep your feet on the chords of the
trusses and you'll be fine.
B

"k boeheim" <kbo...@rochester.rr.com> wrote in message
news:GP_o8.43055$v%.11623815@typhoon.nyroc.rr.com...

[db...@sprynet.com]

I looked in my Wood frame construction book and i think you are talking
about the ceiling joists.. the wood that runs ontop of the sheet rock or
whatever type of ceiling material you have installed.. No mention was
made of trusses(i think trusses are the members that go from the roof
rafters to the ceiling joists??? for support.. they do list as the
lowest (2 by 4 in celing joists spaces like this:
size spacing group A group B group c group d

2X4 12 in 9-5 ft/in. 9-0 ft/in 8ft.7in. 4 ft. 1in.
2X4 16 in 8 ft.7in. 8ft.2in. 7ft.9in 3ft. 6 in.

it does not say what each group(A,B,C,D) is but as you can see the
higher the group the more weight it will hold

the chart goes on with 2 by 6, 2X8, and 2 by 10 lumber
it says that the spans for ceiling joist, figured for a normal dead load
and a live load of 20 lbs per sq. fto-- permitting the attic to be used
for storage(national building code) thinking back my mother had a home
that must have been built right after WWII. the entire attic area was
made out of 2 by 4 lumber and it was all marked with nubers adn the wood
was bolted together(they must have cut up and shipped these housed to
location and then set them up and finished the houses(we did not own it
until years later(most of the houses in the area looked alike, match box
construction???).... I got up in the attic many times and never had a
problem(i was a kid, early 20s and skinny back then) never had any
problems jumping around in that attic going from one ceiling joist to
another, but reember that house was bolted together..... if the wood you
want to walk on is the 2 by 4 's that are laying down on the ceiling
then cut some plywood about 2 1/2 ft by 3 ft. and take it up with you to
put across two or more boards(ceiling joist) and sit on these when
working on the wiring... remmeber that you want to spread the weight
around as much as possible..... its PSI, pounds per square inch that
count.. keep the squares as large as possible and you will not have any
trouble... also when moving around up there try to be gentle, too much
force getting up too quickly is just like trying to kick a hole in the
ceiling(alot of force going to one area at one time)...
hope this helps.

[sciengmba]

You should be fine if before moving on the trusses you place a sheet of
plywood/OSB or some runners acrood the trusses. Most truss manufacturers'
engineers design them to take a minimum "worker" load (a hypothetical
individual plus tools, and keg).

k boeheim <kbo...@rochester.rr.com> wrote in message
news:GP_o8.43055$v%.11623815@typhoon.nyroc.rr.com...

[wizard4938]

Did the same thing a few years ago and offer the following:

If you're up there in hot weather take a bottle of water up with you. It's
much easier than I thought to get seriously dehydrated (attic in Dallas in
July). Damn near passed out without even realizing what was wrong.

If one end of the wire is going to the speaker, then the other end must be
going to wherever your sound system is located. Assuming that you're going
to the trouble of fishing the wire down through a wall to come out near the
floor, tie a string to the last wire that you fish through and pull it
through from the attic with the wire. Whatever sort of connector, wall
plate, or feed through that you intend to have at the wall, ball up a foot
or so of the string and tie it down. If you ever need to run any additional
wire up the same path, you'll have a pull string in place that'll save you a
lot of work.

Lastly, if it's practical in your installation, leave a drip loop somewhere.
Preferably inside the wall at the bottom, below your exit point. If there's
ever water in your attic, you don't want the wire to give it a path straight
into any electronics. A loop of wire, physically below anything electronic
can give water a place to "drip off" and prevent major damage.

Just my 2¢

Bob

"k boeheim" <kbo...@rochester.rr.com> wrote in message
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[Bill Hewitt]

<db...@sprynet.com> wrote in message news:3CA492...@sprynet.com...

He's talking about the chords of the roof trusses. They are where the
ceiling joists are with a stick built roof.

[k boeheim]

Thanks to all for your responses....and 2ข. I feel much safer now, I think.

kb

"k boeheim" <kbo...@rochester.rr.com> wrote in message
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