building new chimney - sealing chimney where it meets siding?

[psychmike]

My builder is not sure about the best way to seal the chimney/chase where it meets the siding of the house.

We are building a new house and doing a wood-framed chimney with cultured stone exterior (and a zero clearance fireplace that you guys helped me choose), and the builder is unsure about something. Where the stone veneer/mortar meets up with the cedar siding, he says that he is unsure about how to get a good seal. He is thinking that he should just use some kind of caulk - (silicone?).

Does anyone have any experience with this? Know the best kind of caulk (if caulk is the answer)?

Thanks!

“No where is there
A more ‘appier crew
Than them wot sings
“Chim chim cher-ee
Chim cher-oo!”

 

[Sandor]

The only long lasting way is to flash behind the cultured stone and cedar.

Have him bend a 6 inch wide piece 90 degrees (so its 3 x 3 ) and it should be 10' long if he's using a standard brake. This should be put in the corner over the sheathing (and Tyvek) and under the cedar and stone. Make sure the bottom extends over past the sill plate, and if its a two story home, lap multiple pieces at leastl 4 inches.

Use 2" ring shank nails with a dab a silicone on the head where it meets the surface.

This will last the life of the house and will not leak. Spooging tubes of silicone at the joints from the outside is not the answer.

 

[psychmike]

Thanks Sandor. What I did not understand, I'm sure he will.

 

[elkimmeg]

Sandor is simply saying to bend metal flashing at least 3" /3" 4/4 better in the intersection behind the 90 degree bend the chimney chase and existing side wall and let it extend beyond the sill and over the foundation. Another way is to use a strip of ice and water barrier in place of the metal flashing Now that you have the sheething protected and have directed the water infront of the foundation. I would use a 1 by 2 PVC 3/4" called Assac instead of wood straight edge in the corner it will never rot, never need replacing

Caulking can be used to neeten up any joints but not the permanent water seal. In most cases caulk should not be the only line of protection and never used to substute for proper installation

 

[Sandor]

Sandor is simply saying to bend metal flashing at least 3" /3" 4/4 better in the intersection behind the 90 degree bend the chimney chase and existing side wall and let it extend beyond the sill and over the foundation. Another way is to use a strip of ice and water barrier in place of the metal flashing Now that you have the sheething protected and have directed the water infront of the foundation. I would use a 1 by 2 PVC 3/4" called Assac instead of wood straight edge in the corner it will never rot, never need replacing

Caulking can be used to neeten up any joints but not the permanent water seal. In most cases caulk should not be the only line of protection and never used to substute for proper installation

Elk, the only reason I do not like the Ice and water shield is that it can crack at the fold in cold weather, but I have alot of friends that use it with success.

I like the Assac suggestion. Never done it that way!

Nice to know I passed your "inspection", inspector.!!

 

[elkimmeg]

Good contruction practices allways pass inspections. True about ice and water barrier but carefully installed it will work. Not as good as your suggestion the metal flashing suggestion and application description is the best solution. If you are that concienceous, I doubt we would ever have those negative discussions