Stove leg length impact to required Hearth R value

[HarvestMan]

Can anyone here provide me the impact of changing stove leg length on the required hearth R value. In searching for this information, it appears it is addressed in NFPA 211, but I could not find the latest copy available for free.

Specifically, I would like to know if I reduce the leg length of a Woodstock Fv by 1.75 inches, how much would this increase the hearth R value requirements. I have not found a published R value requirement on the WS website, but when talking to them on the phone they tell me it is .59 for the Fv.

I have already inquired about them producing a custom leg length and they refuse as this will "invalidate their listing". I have not asked them this question as I suspect that they would not want to touch it because of liability fears.

I know this is an odd-ball question, but I am the odd-ball who would consider doing it if it can be done safely.

Thanks.

 

[begreen]

It cancels the testing certification. This is untested and probably an instant invalidation of the warranty. That's the question to ask them.

 

[rideau]

Yes, that's what Woodstock is telling you. If the stove has not been tested with a specific height leg, then the required R value has not been established, and the stove cannot be installed with that configuration if the leg length is less than the tested leg length. It would not meet insurance requirements, and might well not meet your locality's requirements. You'd be up the creek if you had a fire.

And you have not only a question of R-value, but also clearances. I'm sure your pad would have to extend further into the room in front of the window, and likely also further on the sides and back. But without testing, there is no way to know exactly how much further. The floor in front of a Fireview hearth pad gets quite warm with a legal install.

 

[HarvestMan]

Thanks begreen and rideau. You are both correct. It throws the stove into the "untested" designation for the standard and raises the red flags for home owners.

Just got this same information from conversation with WS.