Question for people that have laid block.. walls that aren't divisible by 8"

[NathanS]

Is something like this, where every course would need one block cut to 12" length going to be a major headache?

I am thinking about doing it this way because I am doing a slab 8" above grade, but I would like to run the block 2 courses above that to get all my framing above the splash / snow line. I would like to align the wooden framing with the inside edge of the CMUs.

[Redoverfarm]

Is something like this, where every course would need one block cut to 12" length going to be a major headache?

I am thinking about doing it this way because I am doing a slab 8" above grade, but I would like to run the block 2 courses above that to get all my framing above the splash / snow line. I would like to align the wooden framing with the inside edge of the CMUs.

Are you going to lay the block with mortar or dry stack and bond.  Your block are not a true 8" or 16".  Generally they are 3/8" off both ways to have a 3/8" mortar joint to make them the true dimensions.  If you have taken that into consideration and still have to cut a block just make sure that the smaller block is staggered in each course and not at the same location of each course.

The accepted practice is to bolt a sill plate onto the last course, rim joist and then floor joist.  There will be some difference in width with the sill plate and the block.  Setting the sill to the outside of the block with a foam seal.  Also you should allow for a drip edge/flashing to cascade over the exterior of the block and not run between the sill and the block.

[NathanS]

Are you going to lay the block with mortar or dry stack and bond.  Your block are not a true 8" or 16".  Generally they are 3/8" off both ways to have a 3/8" mortar joint to make them the true dimensions.  If you have taken that into consideration and still have to cut a block just make sure that the smaller block is staggered in each course and not at the same location of each course.

The accepted practice is to bolt a sill plate onto the last course, rim joist and then floor joist.  There will be some difference in width with the sill plate and the block.  Setting the sill to the outside of the block with a foam seal.  Also you should allow for a drip edge/flashing to cascade over the exterior of the block and not run between the sill and the block.

I'm laying with mortar. I have to do things a little different because I want the sill plate to be on the inside edge of the CMU, instead of outside. Also because I am doing a stem wall there is no rim joist/ floor joist.

Sounds like it shouldn't be too much of an issue - staggering joints won't be a problem. I am planning to use vertical rebar so I will just have to work around the one section of wall where the hollow cores may not line up.

The easiest way to cut a 16" long block to 12" is probably with an blade rather than mason hammer I'm guessing.

[Redoverfarm]

I'm laying with mortar. I have to do things a little different because I want the sill plate to be on the inside edge of the CMU, instead of outside. Also because I am doing a stem wall there is no rim joist/ floor joist.

Sounds like it shouldn't be too much of an issue - staggering joints won't be a problem. I am planning to use vertical rebar so I will just have to work around the one section of wall where the hollow cores may not line up.

The easiest way to cut a 16" long block to 12" is probably with an blade rather than mason hammer I'm guessing.

Little confused.   Is it not possible to build the stem wall off the block.  How do you plan to support the stem wall? Were you going to come off the concrete slab?  What are you planning on doing with the block adjacent to the stem wall perimeter.

Cutting is fairly easy.  Just pick up a couple of mason blades for your circular saw.  Yes they are generally on 7-1/2" but should cut the web from both sides.  You can use a speed square to rest your saw foot against with the offset distance or just mark with the speed square and saw.  Real accuracy is not that important as in wood because irregular cuts are filled with mortar but you will be close.

[NathanS]

Hopefully this helps explain..

Stemwall.. i just mean the courses of block I will lay above the slab. Then above that frame a 'pony wall.'

[Redoverfarm]

Just curious.  I know that is what killed the cat.  But why pour a concrete slab 8" above grade.  By raising the height of the slab typically 4" thick then you will need to fill 4" with stone or other material compacted to eliminate the possibility of cracking.  I found it best to leave as much undisturbed soil as possible and use a thin layer of stone to level it out.  How high will your "pony wall" be off of your block?  OK I think I understand what you are attempting to do in regards to the stem wall and using the slab as your floor.  I built a garage similarly and am about at the drywall stage.  Been trying to address the drywall attachment and baseboard to the block.

[NathanS]

Just curious.  I know that is what killed the cat.  But why pour a concrete slab 8" above grade.  By raising the height of the slab typically 4" thick then you will need to fill 4" with stone or other material compacted to eliminate the possibility of cracking.  How high will your "pony wall" be off of your block?  Is this going to be a basement/first floor or crawlspace? 

Might be a bit of confusion here because I'm not good with all the construction jargon. The top of the slab will be 8" above grade.. this is how just about all 'slab on grade' foundations are done as far as I know. I should have just said it's a slab on grade. I'm basically building the house like it's a garage. Maybe I'll just call it the garage house.

By code, we need to remove all the top soil and then backfill & compact with granular material. We will also be putting down 4" of XPS foam below the slab.

The full height of the downstairs will probably be 8' 4.5" (our lumber supplier only sells 96" studs), so the 'pony wall' will be 84.5" i believe.

[NathanS]

Haha yes, you edited your post while I was replying - I was saying that I'm building my house like most people build their garage.

[Redoverfarm]

Haha yes, you edited your post while I was replying - I was saying that I'm building my house like most people build their garage.

Yes I did. Sorry about that. 

[NathanS]

No apologies necessary. I just thought it was funny we both wrote the same thing.

Not the most conventional way of building a house but we spent a lot of time trying to balance cost with design and durability, and this is what we came up with.

[Redoverfarm]

No apologies necessary. I just thought it was funny we both wrote the same thing.

Not the most conventional way of building a house but we spent a lot of time trying to balance cost with design and durability, and this is what we came up with.

That is what threw me.  I could visualize it in a garage but not in a residence.  But it will work providing you can find a way to insulate the block below the framed wall. Maybe done from the outside.  Don't know about a vapor barrier