Dense concrete block or breeze block?

[Joe87]

Hi all, 

 I'm building a workshop at the end of the garden. I was planning to build it with single skin dense concrete blocks with a timber frame inside for a small amount of insulation etc. Which type of block would be better though, the dense concrete block or dense hollow breeze blocks? 

 

My second question is, the back wall will be about 9 meters long. Do I need to set columns into the wall for strength and if so what is the distance I would need between them? 

 

Thanks for any help. 

Joe

[PeterW]

9m I would put a pier at both ends and then with 5 blocks in between piers - basically build it with any blocks and every 6 along and lay the piers on flat with the returns on the flat also. You could then just infill between the piers. 
 

Mediums would be fine too - heavies are a bit overkill.  

[joe90]

My garage rear wall is 9m built with mediums and two piers, also 2 piers on gable walls (7m).

[Joe87]

On 06/07/2020 at 07:51, PeterW said:

9m I would put a pier at both ends and then with 5 blocks in between piers - basically build it with any blocks and every 6 along and lay the piers on flat with the returns on the flat also. You could then just infill between the piers. 
 

Mediums would be fine too - heavies are a bit overkill.  

 

On 06/07/2020 at 08:21, joe90 said:

My garage rear wall is 9m built with mediums and two piers, also 2 piers on gable walls (7m).

 

Thanks guys for the info. Ive seen two ways of doing the piers, one where a course is just put against the wall one block on top of the others edge and the second where two blocks are laid on their face on top of each other and two on top of them edge ways side by side....(i hope that make sense). Is one way better then the other?

 

Also another random question. For the corners i notice a lot of people cut 100mm block to create a stretcher bond corner. What is the purpose of this? Is it structural or is it just for looks. I plan on having the outside rendered so the blockwork wont be seen so if i don't need to do a stretcher bond corner i wont bother.

 

Finally when you say medium do you mean medium blocks?

 

Cheers for any help again.

Edited July 7, 2020 by Joe87

[joe90]

7 minutes ago, Joe87 said:

Finally when you say medium do you mean medium blocks?

yes.

 

i would always tie the pillars in, blocks on their side then blocks upright, corners are always better tied in (blocks overlapping).

[PeterW]

If you build a pillar in each corner it really ties in as you get a 225mm overall rather than 100mm

 

I would cut to fit into the corners properly - it’s not difficult and the inside will be invisible anyway when you line with insulation etc 

[epsilonGreedy]

1 hour ago, Joe87 said:

Finally when you say medium do you mean medium blocks?

 

 

Medium = something around 14kg per block @100mm thick e.g. Hemelight https://www.tarmac.com/blocks/hemelite/hemelite-standard/ 

 

1 hour ago, Joe87 said:

Also another random question. For the corners i notice a lot of people cut 100mm block to create a stretcher bond corner. What is the purpose of this? Is it structural or is it just for looks. I plan on having the outside rendered so the blockwork wont be seen so if i don't need to do a stretcher bond corner i wont bother.

 

 

It is just the common sense way to interlock blocks at a corner, you need to have a strong argument for doing anything else. Then having decided on stretcher bond and properly bonded corners the 90/100mm blocks are just a consequence of how the maths works out.

Edited July 7, 2020 by epsilonGreedy

[Declan52]

We don't cut blocks over here for the returns at a corner we just use a standard concrete brick. 

If you don't use a stretcher bond then your joints will be too close and the wall will be more prone to movement and will crack and ruin your render.

Plus try to build a few blocks on top of one another straight up and see how high you get before a butterfly knocks it over. 

[epsilonGreedy]

4 hours ago, Declan52 said:

We don't cut blocks over here for the returns at a corner we just use a standard concrete brick. 

 

 

I have done that a few times when it was too hot to cut a block, the problem is that in the OP's case of a single block wall the brick will either protrude a bit being wider than 100mm or if turned the other way there will be a dip to fill.

[Declan52]

2 hours ago, epsilonGreedy said:

 

I have done that a few times when it was too hot to cut a block, the problem is that in the OP's case of a single block wall the brick will either protrude a bit being wider than 100mm or if turned the other way there will be a dip to fill.

How hot does it have to be to not be able to cut a block??

It's being plastered over so keep it flush to the outside face that you plumb. If the lip if the brick is slightly bigger it will be hidden by the scratch coat.

[PeterW]

1 hour ago, epsilonGreedy said:

 

I have done that a few times when it was too hot to cut a block, the problem is that in the OP's case of a single block wall the brick will either protrude a bit being wider than 100mm or if turned the other way there will be a dip to fill.

 

Not sure I follow here - solid concrete coursing  bricks are 65x215x100. On the corner that would mean the corner comes out 185mm to then next block, or just shy of half a block which is fine for bond. 

[Declan52]

34 minutes ago, PeterW said:

 

Not sure I follow here - solid concrete coursing  bricks are 65x215x100. On the corner that would mean the corner comes out 185mm to then next block, or just shy of half a block which is fine for bond. 

The bricks I used on my house where 103mm wide. The mould must have worn away over time resulting in a slightly wider brick.