Blocks for Base

[tallkenny]

Have dug a hole....created my form for the foundation slab, taken delivery of gravel, rebar, cement and concrete mix to make some progress this weekend.

Problem I'm having is sourcing hollow blocks - apparently suppliers in Scotland have to take these by the truck load so noone stocks them.

I can get 7n blocks 440x215x100. Would these be stable enough to hold the weight?

Should I double up and put them on their sides or could i Get away with a sort of m shape base with some support down the middle?

Any thoughts would be appreciated.

[nissanneill]

Re: Blocks for Base

tallkenny
any solid brick that is used for construction of houses or buildings will be more than adequate.
The reason alot of people use the 8 or 9" hollow cement blocks are that they can be dry stacked and then pour some concrete through the layers with some reinforcing rod as extra strength.
Mortar the bricks as you would in a house or fence and you will have no problems at all. How much weight is carried on your outer house wall even if only have a single story and single brick veneer construction with the roofing and ceiling weight on it? A lot more than a cement slab 4' square and a max of 150 bricks!

Neill

[Archena]

Re: Blocks for Base

Um, Neill, I'm pretty sure brick load bearing walls aren't built the same as brick veneer. Brick veneer is actually brick over balloon with the balloon construction doing the actual load bearing. You're right that a brick wall can more than support an oven but it needs to be two courses thick instead of one. I forget how they're tied together - I think it was alternate bands of parallel and perpendicular. Seems like there was another way as well.

I will hunt around and see if I can find the link I had about it that explained the difference.

[Tscarborough]

Re: Blocks for Base

4x8x16 solids should work just fine, other than being a pain to lay plumb and level. You could also double them up and use wall ties between the wythes. Just be sure not do do a stack bond, which means you will have to cut a few into halves.

[Archena]

Re: Blocks for Base

4x8x16 solids should work just fine, other than being a pain to lay plumb and level.

Oh, sorry, I misunderstood the size - I thought he meant a much smaller brick.

Never mind...

You could also double them up and use wall ties between the wythes.

That was what I had in mind.

Just be sure not do do a stack bond, which means you will have to cut a few into halves.

Awww, come on. We were planning on watching him get finished just to have the base collapse. Why'd you go and spoil it?

[tallkenny]

Re: Blocks for Base

thanks guys - gives me a couple of options to think about.

Might go with a single stacking with an additional supporting wall down the middle.

Using facing bricks so could use wall ties between the bloks and standard bricks to give a bit more strenth

[paulyboy]

Re: Blocks for Base

Built my base out of 400x200x90 single blocks. You'd need to ram it with a Mack truck to knock it down.
Paul

[Neil2]

Re: Blocks for Base

"7n blocks 440x215x100. "

These will be fine. Don't lay them on their sides - they are designed to take load only in one direction.

[nissanneill]

Re: Blocks for Base

Archenea,
it doesn't matter which wall (the brick outer or timber stud inner frames) carries the weight, the outer bricks carry plenty of weight. The lower courses carry all the ones above them, some 30 courses for single story and double that for 2 storey. Count the bricks and add the weight for a total.
When I was apprenticed, we watched them build a 7 storey building with suspended concrete floors with double brick walls. Seven times 30 courses and then a hundred tons of concrete, then another 30 courses and another 100 tons of concrete. Do the sums. Standard fired clay bricks have phenominal compression strength, so a little piddly 150 brick oven sitting on a 4' X 4' X 4-6" concrete slab is nothing in comparison.

Neill

[tallkenny]

Re: Blocks for Base

Foundation poured today - bad day for rain today so hopefully won't affect things too munch. Should have checked the forecast before hiring the mixer...
Arms and hands pretty sore!

[ThisOldGarageNJ]

Re: Blocks for Base

Might go with a single stacking with an additional supporting wall down the middle.

sounds like a good plan,,,,, If it isnt overbuilt,,,,, It isnt built.....
Welcome, Good luck with your build and enjoy
Mark

[Tscarborough]

Re: Blocks for Base

I plan on using 6x8x16 for mine, for cost and ease of laying.