Chimney bracing question

[UPswede]

From the ceiling support box my class A Duratech goes up through the attic to just below the roof. Another 4 ft section penetrates the roof and extends about 44 inches above the roof. There is a metal strap that makes one wraparound and attaches to the rafter on each side in the attic just below the roof flashing. The only other bracing/stabilizing point is where the chimney makes contact with the top of the flashing/siliconed storm collar intersection.

The chimney seems rigid when lightly pushed on from the roof. Do you think this is adequately braced? Thoughts and ideas are appreciated. Thanks.

 

[DougA]

You don't need a brace unless it extends more than 5' from the roof according to code. If it feels secure, I would leave it.

 

[Typ0]

I was going to ask a question about this too. Mine actually moves. So if I bump my stovepipe or something a little I know the whole chimney will move a little and I get some water coming back down the chimney. I haven't done anything with it yet but if my chimney is not rigidly installed do you think that will be a problem? I am not saying the pieces together aren't secured ... I figured the water that came in was because the top of the chimney jiggled when the bottom did.

 

[begreen]

Typ0 how is the chimney supported? Can you describe the flue system in detail? It should not wiggle a lot. Pics are always welcome.

 

[Typ0]

I will take some pictures and provide an explanation in a few days ... it's got strapping supporting it basically. I had someone else do the work he was just putting it back in after it had been removed a few years ago. I figure I need to fix this but it's OK for now. chit that's "put together" can't really move around the joints eventually pay a price....it's got screws in each connection and then is taped properly.

 

[UPswede]

The plumber's strap that encircles the chimney just beneath the roof seems like a Freddy Flintstone way to secure it. I don't think it contributes much to my set-up other than some lateral restriction to movement. Is the connection to the support box and then the storm collar pushed onto the flashing the accepted way to do this ? Seems like any movement at the sc/flashing contact point would put stress on the support box connection.

 

[DougA]

If you don't want to pay the high price for the chimney mfg bracing, here's some photos of what I just did. My chimney was 5' 6", so bracing was required by code but not really required for strength. I already had some 3/16" aircraft cable, the bolts, etc, so my only cost was about $10 for the metal strapping at HD. I formed it into 3 sections to go around the chimney without any tools other than pliers and vice grips. You should only need to have adjustment on one of the cables but you can do all 3 if you really want to. The cable ends still need to be taped. I ran out of time that day.
Do you think I could get any closer to the ridge???

 

[UPswede]

Thanks for the reply, ideas,and pics. My situation is a little different in that I have less than 5' on top of the roof, so I think I will try to come up with a more rigid brace of some type just beneath the roof ( to replace the existing plumber's strap ). It is very helpful to see what you did as I can incorporate some of your ideas into a plan for my bracing of the pipe. I may be over thinking this but it seems like it should be more secure than it is currently.