Attaching aluminum flashing to Durock?

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Pinehrst

New Member
Oct 12, 2021
8
Harrietstown, NY
I have been lurking here for months and soaking up all the knowledge I can. This weekend, I am going to try and construct heat shield walls. Size and spacing is set (NFPA 211). But, could use some advice on construction. Plan: 1/2” Durock using 1.5” electric fence ceramic insulators as spacers. Never worked with cement board. Would like to add aluminum flashing to Durock. Considering drilling and riveting to achieve that. Any advice? Many thanks.
 

begreen

Mooderator
Staff member
Nov 18, 2005
89,791
South Puget Sound, WA
What is the purpose of the aluminum flashing? Is this for looks or ...?
 

begreen

Mooderator
Staff member
Nov 18, 2005
89,791
South Puget Sound, WA
Just visual. I don’t want the weight and cost of tile. Off grid cabin
In that case, skip the cement board. It adds nothing. Just use a sheet of heavier gauge aluminum or painted steel. 22 or 20 ga would work well.
 

Pinehrst

New Member
Oct 12, 2021
8
Harrietstown, NY
In that case, skip the cement board. It adds nothing. Just use a sheet of heavier gauge aluminum or painted steel. 22 or 20 ga would work well.
Will definitely consider your advice Begreen. However, I have already purchased the Durock and flashing. I just don’t like the appearance of plain Durock. The flashing was an attempt to dress it up a little. I will build 4 shield walls (rear and one side for two stoves).

I really appreciate your recommendation.
 

MongoMongoson

Member
Feb 6, 2021
173
Wisconsin
I can't say I have ever tried to attach anything to cement board. Normally, I attach cement board to other things. If I were doing this, I think I would try a truss head screw like this...

But it is likely if you try to run those in with a power tool they will just strip out. You will only need a very low seating torque to attach flashing. A small pilot hole and a hand screwdriver would work.
 
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Pinehrst

New Member
Oct 12, 2021
8
Harrietstown, NY
Cement board appears to qualify as an NFPA non combustible material. All by itself, with a 1.5” airspace next to my cabin wall should work. But, admittedly, I never worked with cement board. So, I really appreciate your review and advice. I plan to go slow, and have the screws you recommended, rivets and some appropriately sized bolts, nuts and washers. We’ll see what works.

If it turns into a mess, and a waste of time and resources, I will likely buy 18 or 20 ga sheet metal as Begreen suggested. I will report back on the result.
 

Pinehrst

New Member
Oct 12, 2021
8
Harrietstown, NY
I tried the 3/16 x 5/8 blind rivets. First worked, but dug into mastic side of Durock pretty deep. Added a small washer to that side on second rivet. It worked like a charm.

Very grateful for the advice. Reassuring for guys like me learning, to know knowledgeable people like you will share their hard earned experience.

Certainly, not a tiled beauty. But I am happy with it.
DB9A8CF5-ABA8-48E9-9C38-DF141B05A38C.jpeg
 
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brenndatomu

Minister of Fire
Aug 21, 2013
6,428
NE Ohio
I tried the 3/16 x 5/8 blind rivets. First worked, but dug into mastic side of Durock pretty deep. Added a small washer to that side on second rivet. It worked like a charm.

Very grateful for the advice. Reassuring for guys like me learning, to know knowledgeable people like you will share their hard earned experience.

Certainly, not a tiled beauty. But I am happy with it. View attachment 283456
That has a "1.5" airspace" behind it? Looks tighter...much tighter.
For a cabin I've always liked the look of an old piece of corrugated tin roofing for a heat shield...especially if it has a little "character rust" on it :)
 

begreen

Mooderator
Staff member
Nov 18, 2005
89,791
South Puget Sound, WA
Thanks for the update. Did the wall behind the stove get the same treatment and is the stove at 12" from the wall shielding?

What is the hearth made up of?
 

Pinehrst

New Member
Oct 12, 2021
8
Harrietstown, NY
That has a "1.5" airspace" behind it? Looks tighter...much tighter.
For a cabin I've always liked the look of an old piece of corrugated tin roofing for a heat shield...especially if it has a little "character rust" on it :)
It is 1.5 inches. I used electric fence porcelain insulators as spacers. Haha. Beauty is in the eye of the beholder.
 

Pinehrst

New Member
Oct 12, 2021
8
Harrietstown, NY
Thanks for the update. Did the wall behind the stove get the same treatment and is the stove at 12" from the wall shielding?

What is the hearth made up of?
I was gifted an old 48x48 copper covered piece of cement board. That is what’s behind the stove. The stove measures 13 inches from back wall, and 16 inches from side wall.

The hearth pad is porcelain flooring mortared to 4” cored concrete blocks. The blocks were placed so an airflow occurs from front/back.

I will now repeat the process for the vintage cook stove in the cabin.

Ray
 
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begreen

Mooderator
Staff member
Nov 18, 2005
89,791
South Puget Sound, WA
I was gifted an old 48x48 copper covered piece of cement board. That is what’s behind the stove. The stove measures 13 inches from back wall, and 16 inches from side wall.

The hearth pad is porcelain flooring mortared to 4” cored concrete blocks. The blocks were placed so an airflow occurs from front/back.

I will now repeat the process for the vintage cook stove in the cabin.

Ray
Clever. It's good that you are thinking safety all the way. I am going to move this to the classics forum seeing it is for pre-EPA stoves.