Question About Reducing Clearances With a DIY Heat Shield

[yelrado]

Hi everyone,

I'm trying to reduce the required clearances on my setup and want to make sure I'm doing it safely. My stove requires at least 10" to combustibles, but I’m hoping to bring that down by half. My stove is a TH-100

My current plan is:

1. Leave a 1" air gap off the wall

2. Install cement board

3. Cover it with tile on the top and sides

4. Leave a 1" gap open at the bottom for air intake

5. Maybe drill don't holes in the top

Would this be enough to reduce the clearance from 10" down to 5", or do I also need to leave ventilation openings (holes or a slot) at the top to allow full air circulation? I’d rather avoid openings on top to keep things from falling into the gap, but of course safety comes first—definitely don’t want to risk a fire.

For reference, here’s where I found the reduction percentages based on shield type:

A non-commercial service in support of responsible home heating with wood - Installation Clearances For Wood Stoves

The Wood Heat Organization was formed to support the public in the responsible use of wood energy in the home. We fulfill our mandate by providing reliable information, by conducting research into wood heating-related issues and by representing the public interest in discussions of policies that...

www.woodheat.org

And here’s another resource I came across regarding custom heat shields

https://www.tinvwoodstove.com/clearance-requirements-shields/

Any insight or experience would be greatly appreciated. Thanks!

 

[bholler]

Hi everyone,

I'm trying to reduce the required clearances on my setup and want to make sure I'm doing it safely. My stove requires at least 10" to combustibles, but I’m hoping to bring that down by half. My stove is a TH-100

My current plan is:

1. Leave a 1" air gap off the wall

2. Install cement board

3. Cover it with tile on the top and sides

4. Leave a 1" gap open at the bottom for air intake

5. Maybe drill don't holes in the topView attachment 342328


Would this be enough to reduce the clearance from 10" down to 5", or do I also need to leave ventilation openings (holes or a slot) at the top to allow full air circulation? I’d rather avoid openings on top to keep things from falling into the gap, but of course safety comes first—definitely don’t want to risk a fire.

For reference, here’s where I found the reduction percentages based on shield type:

A non-commercial service in support of responsible home heating with wood - Installation Clearances For Wood Stoves

The Wood Heat Organization was formed to support the public in the responsible use of wood energy in the home. We fulfill our mandate by providing reliable information, by conducting research into wood heating-related issues and by representing the public interest in discussions of policies that...

www.woodheat.org

And here’s another resource I came across regarding custom heat shields

https://www.tinvwoodstove.com/clearance-requirements-shields/

Any insight or experience would be greatly appreciated. Thanks!

What does the manual say about clearance reduction?

 

[begreen]

If the stove needs a heat shield to reduce the clearance then it must be open, top and bottom, by at least an inch. The framed design shown has the air captive behind it. The top horizontal bar would need to be removed

 

[begreen]

The TH-100 corner clearance of 10" is already below the 12" minimum for an NFPA wall shield. In this case, any greater clearance reduction would require written approval by the inspecting authority. Note that if single-wall stove pipe is used, it has an 18" clearance requirement. Double-walled stovepipe is 6".

 

[yelrado]

What does the manual say about clearance reduction?

The following

> To reduce flue clearances from combustible materials,
contact your local safety department.

Here's the manual: https://www.usstove.com/wp-content/uploads/2025/06/TH100-Owners-Manual-2025.pdf