Stand - pouring cores vs. mortar?

[Cheesehead]

I'm building an oven per the FB guidelines/"manual" - a corner oven, 64" wide stand, with a 30" corner using 45 degree blocks.

Because of the corner blocks, I can't get the blocks drystacked without leaving a gap between them. (The corner blocks are gauged for mortar joints.) This worries me - I'm going to mortar stone over the top, any gaps that could hold water would be a bad idea here where we freeze.

So - I'm wondering about thoughts on mortaring the blocks instead of pouring the cores. Expense, expertise required, labor, etc... I'd probably still pour the corners (with encased rebar) for strength, and I'm going to bond-beam the top layer with rebar.

FYI, I'm also building 5 courses high to get the cooking surface higher.

Thanks!

[dmun]

Re: Stand - pouring cores vs. mortar?

The reason for dry-stacking the block stand is that mortaring a block wall is surprisingly difficult. For an amateur like myself, most of the mortar ends up on the ground or in the voids. If you know how do it, then by all means do. If it is a skill set you need to acquire, you may see the benefit of a work-around.

By the way, with a bit of planning you can cut surprisingly complex angles on a concrete block using an angle grinder. The trick is to plan the cuts where the voids are. You can also fill any corner gaps with mortar mix.

[fxpose]

Re: Stand - pouring cores vs. mortar?

Because of the corner blocks, I can't get the blocks drystacked without leaving a gap between them.

Cut the corner blocks to angle the best you can and form the corner with lumber. Rebar the corner and pour concrete down into the corner form along with the other core voids. That's what I did on one corner of my 4' high concrete block patio build.

[SableSprings]

Re: Stand - pouring cores vs. mortar?

I struggled with how to create my corner installation without having to cut blocks and came up with an idea you might find useful. Playing with the blocks I settled on the design shown in the attached thumbnails. With the open bays on the left and right for storage, my working/usable space was greatly expanded. Take a look at my FB photo album (The Dragonfly Den - posted by sablesprings) or through the bottom photo link on www.sablesprings.com - the carts built for the bays have really proved to be functional.

When I got ready to do the top slab on my free-standing blocks, I had every other support block "hole" plugged with cement bags and poured both the slab and filled the open block voids at once. That filled enough of the block voids to secure the base, tied the blocks to the top slab so there would be no "future movement" of the stand and saved myself a few dollars in concrete costs. I started out thinking I'd mix the concrete for the top slab pour myself. After mixing two 80# bags in a small cement mixer I'd borrowed, I called the local cement company and scheduled a delivery/pour of a yard of concrete that afternoon. I should have done a better job on some of my concrete forms, but everything was done in one day.

Hope this helps...

[Cheesehead]

Re: Stand - pouring cores vs. mortar?

Thanks for the responses! Pour it is, with some "tuck-pointing" to fill the gaps. Plans right now are for the opening to be in the back...

and I'm really going to have to get some of the local college students to help me with a 1 yd^3 load of concrete, since I've got a 25' retaining wall to pour too. I'm thinking 50-60 bags of concrete might get a little tiring.