Question-Strapping Ceilings for Drywall
Before I started reading JLC, FHB, and hanging out here, I’d never heard of strapping ceilings.
Now I am about to finish up this 2 story addition, 14″ BCI joists with about a 22′ span. I want to take a little vibration out of the floor. I have a bunch of extra 1×6.
My truss manufacturer / BCI salesman assures me that if I rip the 1×6 in half and strap the ceiling perpindicular to the span it will help a lot.
My questions: If the joists run North-South and the strapping runs East-West, does the drywall then run perpindicular to the strapping (North-South)?
Do I have to fill in the space on the bottom of the joist between the edges of the strapping with more 1x material?
Are there any concerns about creating a big open area for flame propagation (because fire can now get from joist bay to joist bay) in case of a fire?
Thanks,
DRC
Replies
Dave
Have I got this right - they said you should brace across the ceiling - this will lower the floor ceiling height and you should fill in between the strapping along the joists so that the whole ceiling is level for fixing the drywall too.
A better way ( and more traditional in our neck of the woods in England) would be to fix either herringbone strutting (steel or wood) or solid bridging in wood.This is what is recommended to stiffen floors and reduce the risk of twisting. Bridging should be solid and at least 3/4 the thickness of the floor - Spaced about 4'6". Herringbone strutting should be about 1 1/2 "x 1 1/2 "square.Strutting should be used where the spacing of the joist does not exceed 3 times the joist depth.
As for the fire protection that should not be effected as when its through - its through.
Although check with the codes and fire inspector.
Fine homebuilding I have heard of - what was the other magazine?
Phil
we strap ( furr ) every ceiling..
we never block at the joints...but it is a valid point about fireblocking.. and you will find SOME building inspectors who will insist on it..
the drywall goes on the furring just as if they were the joistsMike Smith Rhode Island : Design / Build / Repair / Restore
Run the drywall perpendicular to the strapping just as though the strapping were the joists.
Another advantage of strapping is that it helps isplate noise. Sounds are vibrations that travel better through solids than through air. With the strapping in place you have less solid contact to carry those vibrations and less sound follows through.
I read an article that pointed out that strapping placed at 16"oc does more to help stabilize joists and floor systems than solid blocking placed at four feet oc. Not only is the frequency greater but you are using a sandwhich effect.
Excellence is its own reward!
"The first rule is to keep an untroubled spirit. The second is to look things in the face and know them for what they are." --Marcus Aurelius
Thanks, guys. Y'all are a real blessing. I'm going to go ahead and try it.
Piffin, if you can remember where you saw that article, I'd like to get a copy of it to show my inspector. I doubt if he's ever seen this before, either. Thank you for that comparison -- I was actually wondering about that.
Phil, JLC (Journal Of Light Construction)used to be one of the most closely guarded secrets in construction education and training. As far as I know, the only way you found JLC was to know someone who already knew about it, and it was subscription-only. I would guess that since it's recently been bought by a big corporate-type publishing company, it's probably going to become more widely available. Anyway, you can find it on the web, jlconline.com. Despite the change in ownership, most of the old editorial staff is still there, and it is still a darn good magazine and a highly worthwhile resource for training your crew and yourself. But then, I'm a little prejudiced. <G>
Mike, thanks for the response. I always very much appreciate any help, ideas, and guidance I can get from you.
DRC
I don't remember for sure but would bet on JLC - in those series of update articles near the front of every issue.
Maybe 2-3 years ago. If you are a paid member over there or have the CD, it shouldn't be too hard to find.
Excellence is its own reward!
"The first rule is to keep an untroubled spirit. The second is to look things in the face and know them for what they are." --Marcus Aurelius