How to lay a concrete lintel?

[Simplez]

This is the job of the builder but I want to make sure he hasn't missed anything. Its the first time I have had any building work done in any property I have lived in.

The wall is a single leaf internal brick wall supporting the floor and wall above. I believe the wall above also supports the ceiling joists - the loft is not habitable and is empty

He has suggested the following

1.1500mm span to use 1800mm concrete lintel 100x 145 is the R15a orientation (this has been confirmed by the lintel supplier)

2. Use 4 acro props spaced out no more than 1m apart and Timber needles as well as Timber support for props which will be on solid wooden floor.

3.The lintel will be placed on bedding mortar (4:1 mix) and if required engineering brick - padstone is not required.

4. Once the lintel is placed on bedding mortar to leave it a day to cure. Then to mortar up the gap above the lintel - about 10mm with a 2:1 mortar mix.

5. Leave the mortar another day to cure again before removing the acro props and then cutting out the bricks below.

I have seen online that some people use slate as packing? Why would you need packing. I have some old blue slate from my roof - could that be used for packing or is there a special kind for lintels?

 

[^woody^]

Always slate/dry pack as mortar will shrink. Do this as soon as the lintel is in, not the next day. Then you can remove the props on the same day.

 

[Simplez]

Always slate/dry pack as mortar will shrink. Do this as soon as the lintel is in, not the next day. Then you can remove the props on the same day.

Thanks Woody. Really appreciate your help.

So they lay the lintel in place. Put the mortar mix ontop of the lintel and then raise it up and compress the mortar mix so its no more than 10-15mm.

Then place slate wedges and drypack where the lintel will rest.

Or

The lay the lintel on a bed of mortar and then wedge in slate and drypack on the top side. So squeezing the lintel from the top down.

Then remove the acro props and chisel out the bricks below to make the opening.

 

[^woody^]

The lintel can be laid without a bearing bed, or with just a smidgen to level or hold it, or with a bed and a small piece of slate to prevent the bed compressing.

Then hammer in slate above the lintel in sections to for a tight fit but not to lift the wall or push the lintel down. Then infill between the slates with mortar.

Then be careful not the bang the wall about too much when forming the opening.

 

[Simplez]

The lintel can be laid without a bearing bed, or with just a smidgen to level or hold it, or with a bed and a small piece of slate to prevent the bed compressing.

Then hammer in slate above the lintel in sections to for a tight fit but not to lift the wall or push the lintel down. Then infill between the slates with mortar.

Then be careful not the bang the wall about too much when forming the opening.

Woody you are a credit to this forum.