brick type and lintels

[LSB]

Hello

We are converting a barn built with single skin block with existing window openings.

On the rear wall we are increasing the wall height by 1 block.  We need to put a lintel in place within the 1 block which equals 3 bricks height by 2 bricks long, so 6 bricks per block.

The lintel for this small ensuite window is 1 brick height.

 

My question is, do we go brick, lintel, brick or lintel brick brick or brick brick lintel.

This is the top row of the wall and the wall plate and roof will be directly above, this is a flat roof (4 degrees) and this is the low end.

 

As an existing single skin block wall the exterior is going to have EWI.

 

As the bricks will be totally hidden is there a particular brick we should use or is it just cheap and cheerful.

Also is it okay to use just one block either side of the window.

 

We were planning on 3 bricks to stagger the block, is that correct.

 

[Mr Punter]

A concrete lintel may be simplest.  The height of the lintel depends on the opening width.  They tend to be the equivalent of 1 or 2 bricks high.  You can just sort out the arrangement of bricks to suit the height you would like the lintel to be set at.

[epsilonGreedy]

Have you thought about the internal appearance? Brick Brick Lintel will give little drop from the ceiling which could look odd.

[Temp]

+1

Think about curtains. Do you want the rail on the wall or hanging from ceiling? I think if you want it on the wall you need at a few brick courses of height between top of window and ceiling/plasterboard.

[Temp]

6 hours ago, LSB said:

The lintel for this small ensuite window

 

If its just 1 block wide it will be quite narrow. Too narrow to escape through but I can't remember if a window in an ensuite has to be wide enough to be an escape window or not.  

 

The minimum bearing end for the lintle is 150mm but might be better to increase that to half a block eg so the lintel is two blocks/four bricks long like..

.

 

 

Edited May 2, 2021 by Temp

[LSB]

14 hours ago, epsilonGreedy said:

Have you thought about the internal appearance? Brick Brick Lintel will give little drop from the ceiling which could look odd.

In this wall we are very limited with height, it will only be 10 blocks which equates to 2100 with mortar max

 

[LSB]

12 hours ago, Temp said:

+1

Think about curtains. Do you want the rail on the wall or hanging from ceiling? I think if you want it on the wall you need at a few brick courses of height between top of window and ceiling/plasterboard.

This is an ensuite and will have frosted glass.  It looks straight at a bank which will have gabions at some point and is higher than the wall so I wasn't going to have curtains here.  There is then an agricultural field so no one passing.

But, that same wall runs the length of the house which will include 2 bedrooms.

This particular window is pretty small at only 800 wide, but the bedroom ones will be much wider so will have thicker lintels and will need curtains so I do need to consider that and, of course, I want them all to match.

This lintel is 1 brick high.

 

[epsilonGreedy]

4 hours ago, LSB said:

In this wall we are very limited with height, it will only be 10 blocks which equates to 2100 with mortar max

 

 

I make 10 blocks to be 10 x 225 + 50 wallplate minus 18mm skimmed plasterboard = 2282 which is a useful addition to what you calculate.

[LSB]

5 hours ago, epsilonGreedy said:

 

I make 10 blocks to be 10 x 225 + 50 wallplate minus 18mm skimmed plasterboard = 2282 which is a useful addition to what you calculate.

I thought the blocks were 210, sounds like I need to check my measurements in the existing blocks.

We have existing walls that we have to keep, I wonder if the sizes have changed since the barn was built in the 60's.

 

[Temp]

10 hours ago, LSB said:

This particular window is pretty small at only 800 wide,

 

Ah ok . I misunderstood and thought you said 1 block wide which really would be small.

[PeterW]

1 hour ago, LSB said:

I thought the blocks were 210, sounds like I need to check my measurements in the existing blocks.

We have existing walls that we have to keep, I wonder if the sizes have changed since the barn was built in the 60's.

 

Blocks are 440x215, so 450x225 with a 10mm mortar bed. 10 to the square meter. 
 

If the blocks are slightly smaller then they could be imperial but will only be 5-6mm 

[LSB]

11 hours ago, PeterW said:

Blocks are 440x215, so 450x225 with a 10mm mortar bed. 10 to the square meter. 
 

If the blocks are slightly smaller then they could be imperial but will only be 5-6mm 

Thanks, I will measure later to confirm, I know the new blocks we have ordered are hollow 440 * 215 and 140 depth, the new blocks for some of the internal walls and external are 100 deep and not hollow.

 

Another question.  A few of the old blocks are split through the middle so we are going to remove and replace.  The SE said it is long standing and not an issue.  These broken blocks are at ground and first level, nothing split higher up.

But, as well as that quite a few show the vertical mortar joint is cracked.  We were planning to also replace these rather than try any sort of repair.  Is that the right thing to do.

Insulation on all these existing walls is EWI with plasterboard inside.

[PeterW]

Just leave the old ones alone - they won’t go anywhere. 
 

Any reason for using 140mm hollows ..? 

[LSB]

1 hour ago, PeterW said:

Just leave the old ones alone - they won’t go anywhere. 
 

Any reason for using 140mm hollows ..? 

because that is what the existing wall is built from and we have to make a few changes for the new roof.

This is one block height increase for the 24.5m back wall.

 

The old ones with cracks, either in the block or the mortar, won't that cause problems with cold bridges?

 

[LSB]

Next question re the hollow blocks.

I can't find any details on how much mortar it will take to fill each block, I know each side and level is 10mm * block depth, but how do I calculate the middle.

I've done lots of googling, but can only find details for H blocks which are 200 deep whereas these are 140 and have 2 ovalish holes.

 

[LSB]

More about these lintels.

 

I've been looking at lintel calculations, which takes into account the weight above.

But, these lintels will have one brick above, to make it level with the blocks, but it is then the roof.

 

How do I calculate what I need in the scenario.

Yes, I am getting an SE, but I'm just looking at designs and wondering how it works.

 

 

[PeterW]

Are the lintels taking the load from the roof or just spanning a gap and taking the brickwork load only ..?

[LSB]

11 hours ago, PeterW said:

Are the lintels taking the load from the roof or just spanning a gap and taking the brickwork load only ..?

 

The roof is technically flat @ 12 degrees and this wall with 6 windows is the low side, so I guess it is taking the load.

 

[epsilonGreedy]

Roof weights vary a lot, what type of tiles are you using?

 

How wide is the window aperture?

 

What type of lintel are you using?

 

A two brick high 140 concrete lintel with two steel reinforcement bars running through it should cope.

[Temp]

 

15 hours ago, LSB said:

But, these lintels will have one brick above, to make it level with the blocks, but it is then the roof.

 

I think metal lintels are meant to have more than one brick course above them? Minimum of 3 courses I think.

[LSB]

3 hours ago, epsilonGreedy said:

Roof weights vary a lot, what type of tiles are you using?

 

How wide is the window aperture?

 

What type of lintel are you using?

 

A two brick high 140 concrete lintel with two steel reinforcement bars running through it should cope.

The roof will be raised seam zinc or steel.

Windows vary in width as follows.

1. 1175

2. 1870

3. 1000

4. 1860

5. 1500

6. Not measured yet, but probably 1860, it's still a shed for storage and won't be cleared until we have an outside workshop.

 

I haven't decided on the type of lintel yet, I was going to use steel, but not for any particular reason except they weigh less to lift up.

Do the lintels already have steel bars running though.

 

I also wondered about BC, do they just allow whatever is there.

 

These windows are all for existing openings in the barn along one side.

 

The North & East side will all be new ones in a new wall.

The West side will be new openings in existing walls.

 

[LSB]

1 hour ago, Temp said:

 

 

I think metal lintels are meant to have more than one brick course above them? Minimum of 3 courses I think.

So, that will work for the high edge of the roof, but not for the South side as we are very limited with the height of the roof and the windows will be right at the top of the wall as this is how the openings already are in the barn conversion.

[Temp]

Sorry I can't really remember why they say three courses. Might be due to the lintel deflecting or might be to do with preventing it twisting? Hopefully someone else will know.

[PeterW]

3 course is standard but these - if they are supporting the roof - will need to be “garage door type” or XL cavity type. I would in this instance use steel - I’d also go for a full length steel end to end and pin it either side of each opening with resin bolts.