Lintel question

[MarkW1979]

Perhaps someone could just keep me right on quick lintel related question just to set my mind at rest.

 

The Structural Engineer (who unfortunately I don't place to much faith in anymore!) has specified the following lintels for the outer skin of the 1.75 storey timber kit which will be 100mm blockwork:

 

1. Unless noted otherwise on the drawings, lintels in blockwork cladding to be ‘Robeslee’ prestressed concrete lintels type E (100 x 100mm deep) with 150mm end bearing.

 

I have a couple of patio doors 3m in length so a 3300mm lintel. 100mm x 100mm doesn't seem a lot to me, but maybe I'm overthinking things?!

 

Many thanks,

 

Mark

[Mr Punter]

It really depends on the loads above, but 140mm high will be a lot stronger.  You need to get the engineer or the lintel people to confirm.

[MarkW1979]

Thanks Mr Punter

[Dave Jones]

no way would i use a conc or off the shelf lintel above a bifold. They always flex in the centre which could pinch your door and make it not open smooth. A 3 m section of steel rsj will guarantee it wont.

[Big Jimbo]

I think Building control will want to see some sort of calc . I would if i saw a 100mm concrete lintel that wide holding a load of blockwork up.

[joe90]

In my build we used concrete lintels over bifolds about 3m long but they were more like 150 deep and brickwork above.

[MarkW1979]

Thanks guys - i spoke to my brickie who says use a K9 (100mm x 215mm). The Structural Engineer has been useless from start to finish...