What kind of morter to use to replace some stones on stone fireplace

[JimA]

I Just purchased a new Quadrafire 5100 wood insert to replace the old obsolete unit that I had in the fireplace before. When I removed the old one I had to remove some of the stonework to get the old one out. Just wondering what kind of morter to use to replace some of the stones. I need to fill in about a foot gap over the top of the opening. The old one had a large open box on top of stove that left a big gap in the stone work when it was removed. Any help on the proper mixture and type of morter to use would be of great help. Thanks

 

[webbie]

I Just purchased a new Quadrafire 5100 wood insert to replace the old obsolete unit that I had in the fireplace before. When I removed the old one I had to remove some of the stonework to get the old one out. Just wondering what kind of morter to use to replace some of the stones. I need to fill in about a foot gap over the top of the opening. The old one had a large open box on top of stove that left a big gap in the stone work when it was removed. Any help on the proper mixture and type of morter to use would be of great help. Thanks

Standard mortar mix should be fine for that - the same stuff you would use for laying bricks, etc.

 

[elkimmeg]

Most of the premixed stuff is a weak mixture Not enough mortar and tends to fall apart prematurely.
What I suggest if you buy premixed buy aanother bag of mortar and mix an additional shovel of mortat in the mix ever forth shovel.

 

[berlin]

elk what r u talking about?? add another bag of mortar to premixed? do you mean another bag of portland cement??

the best mortar for the poster's needs is premixed type S mortar mix ( available at home depot and lows- quickrete calls their's "type S mason's mix").

 

[elkimmeg]

the pre mix is a low containt motar to sand they thinned the mortar part out.. One has to add pure motar to the pre mix or portland cement either or to strenghten the mix. Or purchase sand and motar and not use premix


Berlin recomends the s type premix motar he is right. The common mix is what I was talking about is a warterdown version

 

[HarryBack]

or type N, more commonly known as light mortar (lighter in color). Mortar cement is made up of Portland cement, usually type I, II, or type I&II, plus some hydrated lime. The mortar mix contains, portland cement, hydrated lime, and sand. Most of the masons we deal with completely shun "premixed" mortar and will either buy type N light mortar, or Portland and Hydrtaed lime, preferring to mix the sand, portland, and hydrated lime in their own "secret" recipes.

 

[elkimmeg]

this formular has worked for me 3 heaping shovels of mansory sand for every shovel of motar
or 15 shovels for every 74 lb bag. Some also add lime to increase the tackieness to the mixture

 

[JimA]

Thanks for all the info. Plan on picking up the stove on Saturday so I have to get to work with the cement work.

 

[wg_bent]

What's the recipe for making it refractory morter?