I see these metal strips installed perpendicular to the trusses on some of the newer houses that I inspect. When I was a framer a few years back, the rockers just hung it onto the bottom chord of the truss. What is the thinking or reasoning behind adding these, or is it just to make the ceiling a little flatter?

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Jim Robinson
New Mexico, USA

I think they are for noise isolation.

Furring strips.

As you may know they use to use 1x3 furring strips or strapping every 16 on center perpendicular to the joists.

These are used as furring strip, counter home movement in the home, noise reduction, vibration and such and yes to make a flatter surface and less seam cracks from twisting.

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Ted Menelly
Castle Home Inspection Services
www.inspectmycastle.com

SOUNDPROOFING WALLS ceilings USING RESILIENT CHANNEL AND ACOUSTICAL MAT

Try this

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Jim Luttrall
www.MrInspector.net
Allen, Texas 75002

I wouldn't think using them on the second floor ceiling would have much to do with reducing noise transmission, but it makes sense for flattening the ceiling and preventing cracks. They're not used consistently here, only on some of the newer houses.

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Jim Robinson
New Mexico, USA

The last thing I built in Florida was a 600 square foot addition on my home. All stick framed 16 on center and strapping on the ceiling 16 on center. 5/8 plywood on the roof and About 1 1/8 of plywood on the floor with durock and tile floor over the crawl.

I like the old way of over build that use to be done. By the time I finished with that addition with all the straps and ties and brackets and and and and, it would have been the last thing standing in a hurricane.

With all this 2 foot on center thing going on I would think strapping would be a big plus in the new homes. Tighter home, less likely for ceiling cracks and drywall sags and all the rest of the pluses it has with it. Even the channel on the ceilings would be a big help here in Texas with all the movement going on. Imagine having a well finished smooth ceiling like there use to be in all homes instead of all the knock down used to hide the bad drywall finish on everything today.

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Ted Menelly
Castle Home Inspection Services
www.inspectmycastle.com

Just need to make sure the channel hanging down below the joist does not open up the ceiling area to the spread of fire from a wall section.

Ray

Called "hat channel" here.

Steve,

That's a common name for something similar here too, however, "hat channel" has two "brims" (i.e., flanges), which, when viewed from the end, causes that to look like a "hat".

The channel in the photo only has one flange (like USG RC-1 channel), thus that is resilient channel as the single flange allows the drywall to be attached to the "floating" bottom flange.

With hat channel, the hat channel is securely attached on both flanges (sometimes attached on each flange opposite with a fastener opposite one another and sometimes attached on each flange staggered ever other truss - the reason for the staggered fastening is to allow for some flexibility, whereas if they had just used resilient channel that would have been solved), attaching on both flanges, even when staggering fasteners every other truss, severely limits its flexibility.

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Jerry Peck, Construction / Litigation Consultant
Construction Litigation Consultants, LLC ( www.ConstructionLitigationConsultants.com )
www.AskCodeMan.com

Thanx, Jerry. I thought something was wrong with that "front" flange - just didn't study it long enough.

So, now it looks like a "cap" channel.

Jim,

Around here, I see these above garage ceilings. The rockers that I have spoken to have told me that since the trusses are on 24" centers, the ceilings are more likely to sag. The channels are installed on 16 inch centers, reducing the probability of sagging.

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We have enough youth, how about a fountain of Smart?

Besides the reasons mentioned above resilient channels are also sometimes used for these reasons. I see them most often in apartment buildings where there is a garage above a bedroom.

• They are very common in commercial applications and sometimes the subcontractor who installs them are more comfortable with their use. The same goes for architects who do more commercial jobs than residential. They might include details showing the use of resilient channels in houses.
• They allow quicker installation of the drywall when there is unevenness of the framing. This could be due to unevenness of the lumber, misalignment of the jigs used to make the trusses, or differences in chamber between the trusses. It is common practice to use cardboard shims to account for unevenness of the ceiling plane.These can be tedious to install depending on how many are needed.
• It might be that there was an observation of drywall cracking on similar projects and the builder decided to use them. Their use can reduce cracking of drywall at the seams since there is less expansion and contraction due to the moisture cycles that all buildings experience. Metal does not absorb moisture like wood, hence it does not expand and contract.

There may be other reasons that I can not think of right now but, that's my two cents. Have a great day.

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Mike The Truss Guy
www.WoodTruss.org