Thimble install with cinder block

[bayshorecs]

Still trying to get my head around the thimble install I will need to do.

I have cinder block (8x8x16) on the outside of the house which my 18" long, 6" DuraTech will need to pass through. The thimble has an inside tube shield, front cover and back cover. I know the drywall side will need to have the front half of the thimble up to the block. But, do I need the back half of the thimble going through the block?

Reason is the diameter of the thimble, diameter of the 6" DT pipe, and the size of the block. If the thimble does not need to pass through the block, I can just remove an 8x8 piece of cinder block for the 6" DT pipe.

Not sure what should be done and if I only need to remove the 1 part of a block for clearance.

Thanks!

 

[begreen]

Yes, I think you'll want the outside part of the thimble. This is what you are going to seal to stop water from entering along the pipe. The outside collar will also provide a more finished look. It shouldn't take too much to bust out the additional clearance required for the outside wall collar. You can pre-drill a line of holes to make the edge cleaner when breaking it out.

 

[bayshorecs]

Spoke with Simpson and they said installing a thimble through cinder block is the same as any other wall.

guess I am busting out a bigger hole then

 

[Brian VT]

Spoke with Simpson and they said installing a thimble through cinder block is the same as any other wall.

guess I am busting out a bigger hole then

The same as a combustible wall ? I was planning the same as you. Just busting one block out and framing 12x12 on the combustible side.

 

[bayshorecs]

That is what they said. To make a 12x12 on the cinder block side. I missed the call and they left a voice mail.

Maybe you should call and get a second to verify?

 

[Brian VT]

The email response I got was as if written by tech support in India or generated by a computer program.
It said nothing more than "The cutout for a 6" wall thimble is 12x12."
They didn't address the fact that it was non-combustible or give an explanation. :shut:

Anyway...I've got my 12x12 framed inside, centered between 2 studs which are 16" o.c.
There's a wire running up the side (stapled to) of one of the studs.
It is outside the 12" cutout but I feel like I should do something extra to protect the wire like wrap it in tin foil or something. lol
Am I just being paranoid or is this a legitimate concern ?

 

[bayshorecs]

I would think that as long as the wire is 2" away (which it is if outside of the thimble) you are fine.

 

[Brian VT]

My parts showed up today. I had framed out 12x12 inside and an 8 1/2" hole in the cinderblock. No go. You need 12x12 through the block unless you're not going to use the thimble.
The inside part of the thimble is just a square black cover plate. The outside plate has a 12x12 flange that goes into the block and an attached 10" round sleeve that goes through the wall.
I'm taking pics of every step and will make a "how to" post after I (hopefully) finish this weekend.

 

[Brian VT]

I figured I'd post some relevant pics here. There is a gap where the tee goes into the thimble. I guess I'll have to seal it with high temp. silicone ?

http://www.vermontel.net/~cournoyer/Stove/1.jpg

http://www.vermontel.net/~cournoyer/Stove/2.jpg

http://www.vermontel.net/~cournoyer/Stove/4.jpg

http://www.vermontel.net/~cournoyer/Stove/5.jpg

http://www.vermontel.net/~cournoyer/Stove/6.jpg

http://www.vermontel.net/~cournoyer/Stove/7.jpg

 

[bayshorecs]

Nice work! Do you plan to fill the hole around the thimble/webs with cement or just leave it?

 

[Brian VT]

I hadn't given it a thought. Should I ?

 

[bayshorecs]

Don't know. I was thinking is possible problems with air draft through the hole during the winter. I have no clue though.

 

[Brian VT]

I plan to seal the outside plate to the wall and seal around the pipe where it goes through the plate.
I wasn't planning on filling in the cinderblocks. That's what I thought of when you said "webs".

 

[bayshorecs]

That is what I meant.

I didn't know it that was a problem or not without seeing it first hand. Sealing should be ok I would think.

 

[begreen]

Thanks for posting the pictures. Nice clean job. Was making that opening was a lot easier than you thought?

 

[Joey Jones]

I would seal the hole with a mortar mix and add rocks to reduce the amount of mortar needed,,,This is the best possible job you can do, and when you are dealing with fire....Always do the best job that you can do, and then you can forget about it.

 

[Brian VT]

Was making that opening was a lot easier than you thought?

Nope. lol
I made an 8 1/2" hole originally. I did that with a wimpy 3/8" hammer drill I have using 1/4" masonry bit. That was no fun. Buzzy, loud, and slow. Then I had to hammer and chisel it all out by hand.
When I realized I had to go 12x12 I borrowed my buddy's Bosch. That is the tool for the job ! Like buttah. :coolsmile:
I hammer/drilled with a 3/8" bit at the corners and a few other spots. Then power-chiseled it all out. 20 minutes.
That was at 8:00 last night. I'm sure my neighbors were pleased. lol

 

[Brian VT]

I would seal the hole with a mortar mix and add rocks to reduce the amount of mortar needed,,

Why do you think I should do that ? You're talking about filling up the blocks and also around the 10" diameter thimble tube ?

 

[begreen]

Was making that opening was a lot easier than you thought?

Nope. lol
I made an 8 1/2" hole originally. I did that with a wimpy 3/8" hammer drill I have using 1/4" masonry bit. That was no fun. Buzzy, loud, and slow. Then I had to hammer and chisel it all out by hand.
When I realized I had to go 12x12 I borrowed my buddy's Bosch. That is the tool for the job ! Like buttah. :coolsmile:
I hammer/drilled with a 3/8" bit at the corners and a few other spots. Then power-chiseled it all out. 20 minutes.
That was at 8:00 last night. I'm sure my neighbors were pleased. lol

Nothing like the right tool for the job. You did as clean an opening as any pro could. Now on to the next step.