Blockwork for windows and lintel

[acurachris]

Hi

I am doing the block work on my extension and I'm wondering the best way to continue around the ground floor windows.

I can run a full course of 75mm blocks on top of my wall now which leaves me at the correct height for the window and then the coursing is also correct for the lintel, or I carry on with the block work, insert 75mm under just the window and 75mm under the lintels. Hopefully the my pic will show you what i mean.

I'm thinking option "A" would be best although this means running a 75mm course all the way around the extension, can i cut my Celcon blocks to 75mm for this? They are lightweight blocks by the way.

Not to scale

Cheers for any input.

 

[Bonni]

The top picture means your coursing is out so it doesn't work for your cavity boards to wall ties.

Assuming a 6" (150mm lintel), then run 65mm cuts over it to keep the coursing. Bear the lintels 150mm minimum both sides.

Just close the cavities off with plastic Cavity closers.

https://www.toolstation.com/ybs-24m...feed&msclkid=d8cf3071459c1a1777236c4b686c4114

 

[noseall]

Bottom image. We (me) go to the trouble of cutting the shaped blocks that go beyond the window jamb.

Shaped1

• noseall
• 12 Jan 2019

Shaped2

• noseall
• 12 Jan 2019

 

[acurachris]

Cheers for your reply.

The top picture means your coursing is out so it doesn't work for your cavity boards to wall ties

That's a good point, I didn't think of that!

Assuming a 6" (150mm lintel)

I think it'll be 150mm although not got them spec'd yet.

We (me) go to the trouble of cutting the shaped blocks that go beyond the window jamb

I have a cutting saw, so could do this. They are lightweight (look at them and they snap!) blocks, do you reckon cutting them into an L would weaken them anymore?

 

[noseall]

And yes, I'm a cruel gaffer who makes the lads fill even the backs of the blocks too.

 

[^woody^]

Bottom image. We (me) go to the trouble of cutting the shaped blocks that go beyond the window jamb.

Shaped1

• noseall
• 12 Jan 2019

Shaped2

• noseall
• 12 Jan 2019

Al'right smudger

 

[noseall]

you reckon cutting them into an L would weaken them anymore?

They can't be any weaker than a block that has been deliberately cut. I do agree that for what strength you get from the more slender angled cuts, you may as well not bother. But for those with a bit of meat left - worth the effort methinks.

 

[noseall]

Al'right smudger

That is the back of the external course Woods.

 

[^woody^]

With new blockwork, you always follow a 225mm gauge for the block wall, and deal with openings by having cuts below, and cuts for the bearings of lintels or beams as necessary to get them to the required height, and then if necessary cuts above the lintel to get back to the 225mm gauge of the adjacent blockwork.

 

[noseall]

The 'face' is pointed even though its being rendered....

20181107_143453

• noseall
• 12 Jan 2019

 

[acurachris]

With new blockwork, you always follow a 225mm gauge for the block wall, and deal with openings by having cuts below, and cuts for the bearings of lintels or beams as necessary to get them to the required height, and then if necessary cuts above the lintel to get back to the 225mm gauge of the adjacent blockwork.

Cheers, makes sense!