How do I work on the top of this chimney?

[fire_man]

I'm installing a chase cover and wonder if I should bother patching the old masonry crown ?

Right now the top row of brand new brick have no wash coat on top.

 

[bholler]

I'm installing a chase cover and wonder if I should bother patching the old masonry crown ?

Right now the top row of brand new brick have no wash coat on top.

I wouldn't bother

 

[fire_man]

Thanks I'll leave it. - just wasn't sure if it would add anything structurally.

 

[VirginiaIron]

I'm installing a chase cover and wonder if I should bother patching the old masonry crown ?

Right now the top row of brand new brick have no wash coat on top.

If I understand you correctly, you chase cover will shed the storm water and act as a concrete wash.

 

[bholler]

If I understand you correctly, you chase cover will shed the storm water and act as a concrete wash.

No it will act as a proper overhanging crown which directs the water down past the brick instead of making it run directly down the face.

 

[fire_man]

I could be wrong but i don't think concrete or mortar washes are bholler approved. I can see why based on my experience.

 

[bholler]

I could be wrong but i don't think concrete or mortar washes are bholler approved. I can see why based on my experience.

Nope there are just much better ways to do it

 

[fire_man]

Well I finally got the Stainless cover mounted and thank goodness my measuremts were right on for the cover dimensions and flue cuttout.

It was really hard to get the cover to sit properly. It kept twisting so the corners were popping up and down because the sheet metal was acting like a giant unstable spring. I would almost get it right and then SNAP the sheet metal twisted with a loud bang.

I used some long pipe clamps for it to rest on and all finally went well.

You chimney sweep guys have my utmost respect, this work has not been easy - at least for me.

 

[VirginiaIron]

Will the pipe clamps require periodic tightening or do you somehow have them permanently fixed?

What secures the cap to the chimney? The fabricator did a nice job with the metal. Nice job!

 

[fire_man]

The pipe clamps were a temporary solution. They were used as a foundation for the cover (ie cap) to rest on long enough for me to permanently install cement scews into the cap's skirt. The pipe clamps were used as a solid base so the cover would take on the same shape as though it were resting on say a cement floor in your garage - nice and flat so I could secure it with screws. Without the clamps it twisted and literally SPRANG into a contorted shape that was impossible to flatten even with two people working at opposite corners.

The cover still needs to be secured with Ten 1/4" cement screws around the side skirts. It's the top plate for my SS rigid liner and the liner's top clamp rests on it.

Rockford Chimney made the cap and did a fantastic job. I measured and it was exactly the dimensions I requested and was accurate to better than 1/8". That includes an offset hole for the flue pipe which I was most worried about.

I'll get a picture when its finished - if these thunderstorms ever end!

 

[VirginiaIron]

I was just having fun with the pipe clamps. Just remember that every hole in the flashing is a potential leak to assist/create freeze-thaw damage.

EDIT: Since the liner clamp rests on this flashing/cap-and depending on the gage- I would think one fastener on each side would be sufficient.

 

[fire_man]

I kinda figured the pipe clamp question was for fun but wasn't sure

The only hole in the cap is for the 6" liner to pass thru and that's covered by a storm collar. The cover has its own 1" tall collar that the storm collar rests on.

I propably could get by with 4 screws but Rockford suggested 3 on the long sides and 2 on the short sides. Its a 6' x 3' cover so pretty heavy and tends to want to sag on an uneven crown.

 

[VirginiaIron]

I kinda figured the pipe clamp question was for fun but wasn't sure

The only hole in the cap is for the 6" liner to pass thru and that's covered by a storm collar. The cover has its own 1" tall collar that the storm collar rests on.

I propably could get by with 4 screws but Rockford suggested 3 on the long sides and 2 on the short sides. Its a 6' x 3' cover so pretty heavy and tends to want to sag on an uneven crown.

***ALWAYS*** Go with what the manufacturer suggests.

 

[fire_man]

Yea except I'm not taking their advice that regular silicone sealer is ok to use on the storm collar. I'm using high temp silicone.
I think when the stove is getting fired up while the cat is bypassed, the top pipe temps get high.

 

[VirginiaIron]

Yeah, I used the higher temp silicone as well.

 

[fire_man]

One annoying problem i keep having is I drill the proper holes to accept cement screws but the screw sometimes strips the mortar threads. Its fresh mortar thats cured for about a month.

 

[VirginiaIron]

One annoying problem i keep having is I drill the proper holes to accept cement screws but the screw sometimes strips the mortar threads. Its fresh mortar thats cured for about a month.

Assuming you are drilling the verticle portion of the skirt, IMO, all you need is sheer strength and a blue-n- screw is sufficient. The integrity of the flashing APPEARS strong enough. I do not think you need the strength of tension and sheer that a tap-con will provide.
EDIT: One month old mortar is still pretty fresh but should be cured enough to provide sheer strength since the skirt is very close to the masonry. Maybe you do not need to tighten it so much.

 

[fire_man]

Yes I am drilling the verticle portion of the skirt. I never heard of a blue-n-screw. I have been using 1/4" tapcons. The cover is 24 gauge stainless.

The screws strip the mortar before they even get close to bottoming out - not when I wrench them tight. So far 2 out of 7 have done this. Could be operator error that I did not drill the pilot hole deep enough.

 

[VirginiaIron]

Yes I am drilling the verticle portion of the skirt. I never heard of a blue-n-screw. I have been using 1/4" tapcons. The cover is 24 gauge stainless.

Sorry, nylon/ plastic anchor with metal fastener. Not much tension strength but plenty of sheer strength- see my edit above.

https://www.mutualscrew.com/product...MImOLs2uH33AIVCtbACh3SOwB8EAQYASABEgImQ_D_BwE

 

[fire_man]

Yes those I am familiar with. I thought about using plastic anchors but always had good luck with Tapcons. So far i have been able to drill the pilot hole of the stripped thread deeper and use longer Tapcons with good success.

The biggest problem with the blue anchor is you would have to predrill all the sheet metal holes first with the cover on the crown, then drill pilot holes in the cement for the anchors using the predrilled holes as a guide, remove the cover, drill for the anchors, reinstall the cover - and install screws. And somehow the holes never seem to line up the same way twice !?!