Help with my Hearth pad build

[Descending sparky]

Hello there folks, so today I took the day to go for a drive to the local stone supplier to get this project started! I was pleased with the massive selection he had, I had intended on just buying some flagstone and doing the project! However I was sent there by the fireplace people who are installing my stove and the stone guy showed me some stuff that the fireplace company buys for there pads! So black limestone is what I ended up getting! Looks real nice! So now the next step is to get cutting and lay it all out! I have the raised pad already framed with 2x4's on there side framed all up on 12" centers, and blocked up really well,topped off with 3/4" forming plywood! So once I'm ready to set the stone all in place what mortar/ thinset should I be using? Can I just lay it right on the plywood! I see some people use durrock then lay! I was told you could get special stuff to bond to plywood or just use steel lathe on top of the plywood! Also what should I use to make my "grout" joints In between stones! Also what did everyone else use for a stone sealer if anyone used one at all?

 

[ScotO]

Hello there folks, so today I took the day to go for a drive to the local stone supplier to get this project started! I was pleased with the massive selection he had, I had intended on just buying some flagstone and doing the project! However I was sent there by the fireplace people who are installing my stove and the stone guy showed me some stuff that the fireplace company buys for there pads! So black limestone is what I ended up getting! Looks real nice! So now the next step is to get cutting and lay it all out! I have the raised pad already framed with 2x4's on there side framed all up on 12" centers, and blocked up really well,topped off with 3/4" forming plywood! So once I'm ready to set the stone all in place what mortar/ thinset should I be using? Can I just lay it right on the plywood! I see some people use durrock then lay! I was told you could get special stuff to bond to plywood or just use steel lathe on top of the plywood! Also what should I use to make my "grout" joints In between stones! Also what did everyone else use for a stone sealer if anyone used one at all? View attachment 102349 View attachment 102350

That's going to be a beautiful hearth, Sparky! I do hearths two different ways. In my kitchen, I put down some tar paper. Then, I screwed down metal lath 8" on centers, and put an inch-thick layer of type "S" mortar down. In your install, you would want to "rake" the mortar with a scarifying tool, available at your local masonry supplier. Then, after that layer sets up for a couple of days, you can mortar your stones in place. Leave a gap between your stones for your grout. You can either get some colored grout and install it later with a tuckpointing bag, or just use the mortar that you are installing the stones with and grout as you install the stones.

The other method is to use durock and anchor the stones directly to it. But if you do use durock, for strength and longevity I'd consider putting down some lath and scratchcoat over the durock, as well. Makes a better bond.

When installing the stones, spritz some water on the substrate just prior to setting your mortared stone on it. This will prevent the substrate from sucking all the moisture out of the mortar on the back of the stone too quickly. I've installed literally TONS of natural stone veneer both inside and outside my house using the methods I just described to you with great success! Just remember to keep us updated with pics and descriptions of your progress!!

Some of my stonework can be seen in my NZ3000 fireplace build, in the link down below in my signature box.

 

[Descending sparky]

Ok sounds relatively straight forward, so do I just pre drill the durrock and ten use construction screws to fasten it to the plywood? Also what do I use to fasten the lathe to the Duroc, and is the lathe really needed!

 

[ScotO]

Ok sounds relatively straight forward, so do I just pre drill the durrock and ten use construction screws to fasten it to the plywood? Also what do I use to fasten the lathe to the Duroc, and is the lathe really needed!

The lath is a little bit "overkill" (you did notice my name, correct?)....but I do it so just in case the substrate would shift a little, that I won't get cracks in the hearth.....

You'd probably be OK with heavy duty construction screws, but there are screws made specifically for installing durock. you could use that to install the durock and also use it to install the lath. I also use a small fender washer under the screw when installing lath.

 

[Descending sparky]

Lol I didn't realize that your name was Scotty overkill till you said that haha! Ok so I am going to make a trip to the hardware store Tommorrow to acquire these goods! So type "s" mortar can be used to set the stone as well as grouting it as well! I have a grout float and notched trowel but you recommend using the mortar bag! So I should be able to set all the stone let it cure then go grout everything after its all cured!

 

[ScotO]

Lol I didn't realize that your name was Scotty overkill till you said that haha! Ok so I am going to make a trip to the hardware store Tommorrow to acquire these goods! So type "s" mortar can be used to set the stone as well as grouting it as well! I have a grout float and notched trowel but you recommend using the mortar bag! So I should be able to set all the stone let it cure then go grout everything after its all cured!

Yep.....
You can use the type "S" for grouting, but keep in mind that type "S" sets up quicker than type "N", which is what a lot of masons use for the grouting. You'll just have to "point your joints" as you go. I used a different color mortar to grout with, it was type charcoal colored and type "N".

 

[Descending sparky]

So type "n" may be best for the grout! Also when u say point my joints as I go, what exactly is pointing my joints? Sorry I'm new to the whole masonry thing!

 

[ScotO]

So type "n" may be best for the grout! Also when u say point my joints as I go, what exactly is pointing my joints? Sorry I'm new to the whole masonry thing!

pointing means to 'pack the mortar in' and smooth it out nicely. You'll have to go over the joints several times over the course of an hour or more, as the mortar sets up, to get the joint pointed smoothly. When the mortar is really wet, you'll have to wait til it starts to 'set up' a little. If you are new to masonry, look at some online tutorials to get a feel for what you are going to be doing. Some mortars come 'pre-mixed'. Some mortars, you have to add sand to. Make sure you know what you are doing. I got the mortar that I had to mix myself. I did 3 parts sand to one part type S or type N.....

One big trick is to get your mortar mixed right.
Get it to the consistency of mashed potatoes. Not too wet, not to dry.....

 

[firefighterjake]

Assuming the stove you are getting only requires ember protection or has a low R value requirement . . . if you haven't checked this should be done first before building any hearth.

I personally went with one or two layers of 3/4 inch plywood (I forget exactly how many layers) and then had Durock on top. My reasoning: a) it added some R value even though I didn't need it, b) the extra bit of fire protection at a cheap cost and c) it gave the Thinset (I used Flexbond or something to that effect) to get a nice grip. I screwed down the Durock with the special Durock screws to the plywood and then used the thinset to secure the stone (slate in my case) to the Durock.

To date I have had no cracked stone or grout . . .

As for stone sealant . . . I used the sealant they sell at either Home Depot or Lowes -- one year I went with a matte finish and another year I changed things up with a gloss finish. I think I like the gloss, wet stone look better.

 

[PapaDave]

My thought too Jake. I just looked it up (again) and the T5 only needs ember protection.
(broken link removed to http://www.pacificenergy.net/alderlea/pdfs/ALT5-081112-24.pdf)
Gooder to go, as long as the rest of the clearances are good.

 

[Descending sparky]

Hey thanks for the heads up guys, I did check and ember protection is all that is required! You seem to have noticed my stone to come in my signature! Pics to follow tonight! I spent 8 hours running around and planning / cutting stone all day! I am really pleased with the job I did! I can't wait to slap this stone down on the durrock tommrrow!

 

[Descending sparky]

After a long day I have completed all my cuts and made my " jig saw puzzle" ,first time ever doing stone work! Cracked and broke a few pieces I really wanted in certain spots, cursed and swore a few times! All and all it was a fun project and a great learning experience! Glad I opted out on buying one and looked for months for the right stone to make a custom one! Next step is to lay the stone on the framed up pad Tomorrow after i finish one more peice of durrock! Well I can honestly say that was a solid days work! Seems I'm working harder while I'm on holidays than at work lol! More images to follow when I load the digital camera!

 

[raybonz]

pointing means to 'pack the mortar in' and smooth it out nicely. You'll have to go over the joints several times over the course of an hour or more, as the mortar sets up, to get the joint pointed smoothly. When the mortar is really wet, you'll have to wait til it starts to 'set up' a little. If you are new to masonry, look at some online tutorials to get a feel for what you are going to be doing. Some mortars come 'pre-mixed'. Some mortars, you have to add sand to. Make sure you know what you are doing. I got the mortar that I had to mix myself. I did 3 parts sand to one part type S or type N.....

One big trick is to get your mortar mixed right.
Get it to the consistency of mashed potatoes. Not too wet, not to dry.....

Is your last name Flintstone by any chance? I have a friend Fred Flintstone and he talks a lot like you

Ray

 

[raybonz]

View attachment 102440 View attachment 102441 After a long day I have completed all my cuts and made my " jig saw puzzle" ,first time ever doing stone work! Cracked and broke a few pieces I really wanted in certain spots, cursed and swore a few times! All and all it was a fun project and a great learning experience! Glad I opted out on buying one and looked for months for the right stone to make a custom one! Next step is to lay the stone on the framed up pad Tomorrow after i finish one more peice of durrock! Well I can honestly say that was a solid days work! Seems I'm working harder while I'm on holidays than at work lol! More images to follow when I load the digital camera!

That's gonna look great sparky!

Ray

 

[Descending sparky]

Yes it shall look good! Finished up the durrock and got everything all prepared for laying the stone! Was a bit sore today so I had someone help me bring them into the basement at 7:00am after he got off his night shift! The friend who helped me said he would be back after he slept! He didn't return lol! Guess he got sick of helping me move them as he also unloaded them with me! Guess I will man handle them into place Tommorrow! Just gonna have to work fast I case I wanna shift one a bit I hope the mortor doesn't set before I make my way to the last stone!

 

[raybonz]

Yes it shall look good! Finished up the durrock and got everything all prepared for laying the stone! Was a bit sore today so I had someone help me bring them into the basement at 7:00am after he got off his night shift! The friend who helped me said he would be back after he slept! He didn't return lol! Guess he got sick of helping me move them as he also unloaded them with me! Guess I will man handle them into place Tommorrow! Just gonna have to work fast I case I wanna shift one a bit I hope the mortor doesn't set before I make my way to the last stone!

When I did my hearth I dissected the hearth into 4 quadrants and did one section at a time.. Give yourself enough time to finish what you start then move onto the next section..

Ray

 

[Descending sparky]

Yes yes, I have all the stones layer in front of the pad now! When I had them all cut and placed together outside I took several photos and labelled them with numbers 1-13! So I will start in the back corner and slowly work my way to the front sweeping from left to right down the stone rows till I reach the outer perimeter

 

[begreen]

You are building this in place right? The hearth will be pretty heavy and not too portable when finished.

 

[Descending sparky]

You are building this in place right? The hearth will be pretty heavy and not too portable when finished.

Yeah! It will weigh about 1000lbs once it's done so I I'm not moving it anywhere'! It's being built where it will be for the remainder of my life!

 

[Big Donnie Brasco]

UPDATES!

 

[Descending sparky]

Funny, I just woke up and decided that I have some time this weekend to tackle the ledge stone for behind the stove. Been really busy lately and just haven't had the time to complete the rest of the project, that's life I guess. So off to get some stone and start laying all this stuff out!

 

[ScotO]

Here, I'll adjust it for ya..........



BTW Sparky, it's looking really nice! Can't wait to see it finished. The color of your room is the exact same color of our living room, we love that antique green color!

When putting your pictures on the site, rotate them in your computer before uploading them......it will make it easier to look at them that way!

 

[PapaDave]

Thanks Scotty, my mind could NOT figure that one out this morning.
Ok, what's the blue stuff?

 

[ScotO]

Thanks Scotty, my mind could NOT figure that one out this morning.
Ok, what's the blue stuff?

That looks to be a barrier for water seepage. I'm guessing he's doing a basement install here, and that is to keep it off of the cement pad for condensation/leakage.......just my guess.

 

[Big Donnie Brasco]

That is BEAUTIFUL ... I may have to copy