First time stove install - need advice on chimney lining and hearth material

[contortionst]

Currently renovating my first house and putting in a Morso 04 stove for space heating.

Have a few questions...

We were told by a stove installer that we would need a new chimney liner, as it's always best practice in a house of our age (1940s). However he didn't actually look at the chimney itself and we felt he might have been trying to sell us as much as possible, as his overall price for stove and installation was very high.

We subsequently had the chimney cleaned, the guy who did so said it was in excellent nick, hadn't been used that much (fireplace was covered with plasterboard when we bought the house), and we shouldn't need a liner.

My feeling is that the chimney sweep had nothing to gain and therefore may have been offering the most honest appraisal of the situation - but I'm still unsure. What do you think?

Secondly, for the hearth, I'm looking for a piece of local, natural stone, and limestone seems to be the most obvious choice. I'm in Ireland so Welsh slate, my first choice, is just too expensive to ship. Have people got experience with using limestone as a hearth? Any issues with cracking, cleaning?

Kind regards from a first time stove owner.

 

[begreen]

The 04 is a small stove. If the chimney throat is large or short it may not draft sufficiently. What is the throat dimension of the current flue? If it's more than 250mm it's cross-section could be too large for good draft.

 

[pen]

Welcome to the site! What is the diameter of the current chimney? For best performance, the liner size of the chimney (in square inches) should match the square inches of the flue collar of the unit you are installing. A chimney that is too large will not draft as strongly as an appropriatly sized unit, which means that a modern stove will not operate as well as it others should. With that said, if your chimney is 7x7 or larger, I'd definately be putting a liner in.

Additionally, that chimney has some age on it. Even if it's in good shape now, it hasn't been heated or cooled in years. Who knows how long it will stay in good shape. Also, we've seen some amazing (flammable) framing members burried in old chimneys and fireplaces that definately do not meet clearances to combustibles. That said, a liner (insulated if you can) is really the safest thing to do.

As for the hearth, you can use most anything noncombustible that you wish so long as it meets any r-value requirements that is listed for the stove you are using. Also, make sure it has a large enough footprint to cover your required size with room to spare. I like to look at the next stove larger than the one I am interested in, and pick a hearth that would be big enough to accomodate that, so if I ever need to replace the stove with something larger that I'd be set already.

Also, if you are new to burning, the largest rookie mistake is not having seasoned firewood on hand. To be warned, the vast majority of those selling "seasoned firewood" are selling wood that is no where near ready to burn. Having wood that is truly dry makes the experience so much easier and safer as well.

pen

 

[contortionst]

Thanks for the replies. Current chimney diameter is roughly 8 inches, and the flue for the 04 is about 5 inches.

As for the limestone, does it need to be sealed regularly, or at all? Do you know any good links discussing the benefits of various materials for use as hearths? I've searched far and wide online but so far to no avail.

 

[pen]

here's a chart that lists the r-value of limestone per inch of thickness http://www.chimneysweeponline.com/horvalue.htm

I can't speak to the sealing it part.

pen