Opening up wall with existing beam

[MidsTW]

We want to open up our lounge and kitchen/diner. The wall which we plan to open has what looks like provisioning from the initial build ( some of the new builds of this house type had the doors as standard ).

I’m no expert, but is the beam on the left wall likely to be correct by design, looks like with 220mm either side it would allow a 1300mm opening.

 

[MidsTW]

Can anyone help explain how I should approach this with building control please?

Would I need them to inspect the beam in situ?

Would I need a structural engineer to complete some calcs to verify the beam installed is adequate?

 

[tony1851]

Is it a patented 'box' lintel, or a steel 'I' beam?

 

[MidsTW]

Looks like a box lintel to me. Haven’t stripped the plaster back but from the photos I have pre plaster.

 

[tony1851]

If its a standard box lintel (possibly Catnic?) it will be in their catalogue, giving the maximum load-bearing capacity for any given span. Its actually quite easy to work out the loads - your beam will be carrying part of the floor load, and possibly a wall above. There are standard tables with loadings for things like floors and walls etc.
You would only need a bearing length of 150mm each end, so your clear span could be a littl more than 1.3m.

 

[MidsTW]

I guess I won’t know what manufacturer it is until I get some plasterboard off. I assume it would be marked too?
Asking Taylor Wimpey would likely be useless…
I’m happy to go around the calcs myself but would building control accept this? It is a 2.5 story house but there are no load bearing walls upstairs.

I’ve asked BC for pre application advice as obviously the main work is already in place.

 

[MidsTW]

Also worth adding that there are no brick walls on either the 1st or 2nd floor above this. So I think it is only supporting the joists above and not any other internal masonry walls as there are none…

 

[stevie888]

If you're on an estate then it's quite possible that this has been done elsewhere and BC will be clued up. It looks like a 150 deep box lintel: they are pretty strong

 

[JohnD]

...and you can probably scan the applications on your council's website.

You could copy some.

 

[MidsTW]

Building control have advised that,

If it’s a non-structural alteration with no impact on fire safety, then an application for Building Regulations is not required

Question is.. who is responsible for determining these 2 points?

 

[MidsTW]

Think I’ve found another issue… looking at a photo from the other side it looks as though the lintel would be on half a block of the leveling course which would mean it is effectively on a cut block (builder having to cut it in situ.

I understand this is not correct?

So the builder would need to prop the beam and swap out that cut block for a smaller parsons/engineering brick?

 

[MidsTW]

Or does it mean that that there shouldn’t be a cut in the 150mm bearing length? And we can chop the leveling course bricks back.

 

[stevie888]

The cut isn't an issue so long as the masonry is sound, which it sertainly appears to be.