Should I overengineer my hearth's R value?

[sksmass]

After deliberating about whether to get a Hearthstone Equinox or a Woodstock Fireview I finally pulled the trigger to get a FV. However, I'd like the flexibility, if needed, to change to a stove with a bigger firebox (like the Equinox) if the FV won't adequately heat my space.

So the question is, do I build my hearth the FV specs or do I "overengineer" it to some higher R-value spec on the off-chance that I ever take out the FV and put in somethiing like the Equinox.

The FV only requires ember protection (no specific R value) whereas the Equinox requires R=1 insulation.

So, building to fit the FV I would do a simple Durock plus tile hearth (total height above floor ~ 0.75")
...for the "overengineered" hearth I would do 3/4" Micore, 1/2" Durock plus tile (total height ~ 1.5", R value ~1.8)

Obviously, it would be nice if the hearth was NOT any more of a trip hazard than it has to be. The abutting floor will be covered with carpet on a 1/2" pad and I would do some sort of tapered oak transition between the two finished heights to somewhat mitigate any difference.

 

[IndianaTech]

I suppose it is entirely up to you since your not required by your stove maker. I more then doubled my needed R value of 1.5, but I built an elevated hearth so I was not concerned with overall height.

 

[cmonSTART]

Personally, I think that if you don't mind an elevated hearth go ahead and build it to a higher R value. This will leave you with some flexibility in stove choice.

 

[BrotherBart]

And what about having more protection is wrong?

 

[sksmass]

And what about having more protection is wrong?

The only downside to going overboard on R value is a bigger disparity between the surface of the hearth and the surrounding floor. Frankly, I don't have a sense of whether a 1.5" bump is a trip hazard or not. Measuring a few thresholds in my house I notice that most are in the range of 1/2"-3/4" and they go unnoticed. Is there a "rule of thumb" or even a code that quantifies what degree of surface misalignment constitutes a trip hazard?

 

[Battenkiller]

I'm not an engineer, so I over-engineer everything. Makes me feel safer. Can't see the harm.

 

[begreen]

The location of the hearth may decide the best height. A shallow edge is more likely to be tripped on than a clear rise. If the hearth projects into a moderate traffic area, I would try to make it somewhat prominent and at least a couple inches high. If the hearth is out of the way, like a corner hearth, then this is less of an issue. Our hearth is 3/4" above the floor line and no one has tripped on it yet. But if it was in the middle of the room, I would have made it quite prominent.

 

[firefighterjake]

I suppose there are two ways you could approach this.

1) Build the hearth to the requirements for the stove you bought . . . and realize that should you upgrade and need to beef up the R values you will need to either tear out the hearth or build over the hearth (which personally is what I would do -- simply put down another cement board, level things up and build on top in the future.)

2) Build the hearth to the specs for a stove you think you might want someday . . . realizing that there is a chance that in another 5-10 years there may be another stove with completely different specs for a hearth that you want even more . . . or the stove you think you want for the future may be discontinued . . . or you may not want another stove and be perfectly happy with the stove you bought originally.

I can only speak to what I did . . . I only needed ember protection, but I over-built my hearth . . . not a lot . . . but a bit . . . my thinking was doing so would buy me some peace of mind and there is a possiblity that any future stove purchase may work on this beefed up hearth (although I suspect I would have to rebuild/add to my hearth knowing my luck.) I mainly added the R value just because I sleep easier at night knowing my floor protection is better than what I needed.

As for the height . . . my mindset is a lot like BeGreen . . . if the hearth is flush or a small rise in the floor I would think most folks would not find it to be a trip hazard (much like the 1/4 inch to 1/2 change in thresholds often seen when there is a transition from carpet to wood or vinyl or tile . . . if more of a rise was needed I think I would go up at least a couple of inches to make the potential trip hazard more eye-catching.

 

[Todd]

I say build the hearth to Woodstock specs. I don't think you will need a larger stove, the Fireview will heat your space unless it's a sieve. Keep your chimney at 6" it's cheaper and if you decide to buy Woodstock's new stove later on it will also take the 6".

 

[Slow1]

I say build the hearth to Woodstock specs. I don't think you will need a larger stove, the Fireview will heat your space unless it's a sieve. Keep your chimney at 6" it's cheaper and if you decide to buy Woodstock's new stove later on it will also take the 6".

But what will be the hearth size requirements for the new stove? I'd be generous with the size of the pad if nothing else... Then again I always tend to over-engineer things to some degree. Cost to add a bit during initial design/construction isn't generally very much compared to pulling it out and re-doing it (especially the time involved).

As to added thickness - the comment above about adding 1.5" making it more of a trip hazard: My thought on this is to go ahead and raise it a full 4-5" in any case (whatever r-value you are aiming for). My first pad was a pre-fab that was thin (maybe 1" or so) and I found it more likely to be a hazard of stubbing toes etc than our new one that is build on top of 2x4's on edge (about 5" once it is all said and done). Something about the substantial height that simply makes it much more obvious. Other pros/cons of raised pads have been discussed elsewhere of course.

 

[ChillyGator]

After deliberating about whether to get a Hearthstone Equinox or a Woodstock Fireview I finally pulled the trigger to get a FV. However, I'd like the flexibility, if needed, to change to a stove with a bigger firebox (like the Equinox) if the FV won't adequately heat my space.

So the question is, do I build my hearth the FV specs or do I "overengineer" it to some higher R-value spec on the off-chance that I ever take out the FV and put in somethiing like the Equinox.

The FV only requires ember protection (no specific R value) whereas the Equinox requires R=1 insulation.

So, building to fit the FV I would do a simple Durock plus tile hearth (total height above floor ~ 0.75")
...for the "overengineered" hearth I would do 3/4" Micore, 1/2" Durock plus tile (total height ~ 1.5", R value ~1.8)

Obviously, it would be nice if the hearth was NOT any more of a trip hazard than it has to be. The abutting floor will be covered with carpet on a 1/2" pad and I would do some sort of tapered oak transition between the two finished heights to somewhat mitigate any difference.

I CAN'T BELEIVE YOU FIREVIEW OWNERS DID NOT CATCH THIS: The FV DOES require more than ember protection (or I would already have one)

WOODSTOCK FIREVIEW BROCHURE:
Floor Protection
Your floor needs protection against two hazards:
• radiation from the bottom and sides of the wood stove
• sparks and hot coals that may fall out during ash removal and reloading
Do not install your Woodstock Soapstone stove on a combustible surface (wood floor,
carpet, or vinyl floor for example). Even if you have a stone or tile overlay on wood, it is
still considered combustible since the surface materials will not protect the floor from
radiant heat.
Your Woodstock Soapstone stove must stand on either:
1) a hearth of solid masonry (brick, stone, or tile supported by concrete),
2) a prefabricated hearth pad listed to UL standards. These pads can be placed on
top of a wood or carpeted floor. (Woodstock Soapstone Company carries a
selection of these pads.)
3) a custom designed pad made up of approved non-combustible materials which
will protect the floor from sparks, hot coals and ashes; and prevents heat from
being radiated onto the floor underneath.
If you decide to build your own hearth to go over a combustible floor, start with a
plywood base. Over this apply:
1) a layer of 24 gauge galvanized sheetmetal,
2) a 1/2 inch layer of an approved non-combustible insulation board (such as
DUROCK cement board or WonderBoard Backer Board),
3) decorative non-combustible material such as tile, slate, stone or brick.
The hearth for a Fireview Stove must extend 16” beyond the loading door side. The
hearth should extend 16” beyond the back of the stove and 8” beyond the front of the
stove and beyond the side opposite the loading door. A hearth size of 48” D x 60” W will
meet the safety requirements and be more pleasing.
Hearth Sizes: Minimum Recommended
44” D x 50” W 48” D x 60” W

 

[sksmass]

I don't think we are in disagreement. According to WS's own "plan your hearth" guide (p.4), they suggest 1/2" Durock plus tile as adequate underlayment. Which is the first option I describe. Perhaps "ember protection [only]" is not the proper term, but I have not found any specific R-value spec for a Woodstock stove.

 

[ChillyGator]

It does appear that the installation guide for Woodstock has been updated (since I last looked earlier this spring) and the floor protection specs are more generic. When I looked previously, the R value for floor protection for the Fireview was higher than the Keystone but now no R-Value is given. You are correct and I can now proceed with a more builder friendly hearth project for my future Woodstock stove.

 

[webbie]

A sloping piece of wood around a slightly raised hearth - picture a threshold - might help if tripping is a concern.