Lintel Size/Type Advice

[thomp1983]

Good Morning All,

In the next couple of weeks I'll be getting ready to knock through from our small downstairs bedroom into the old single garage.

I'm going to knock out the section marked above, there will be 300mm to the left for a lintel to bear on and the right side will bear above that pillar, the pillar will be coming out, it's not tied into the outer leaf and will project into the new room too much.

The opening will be approx 2100mm.

The house is a chalet bungalow so that's the roof arrangement above the old garage, the outer leaf is supporting the flat garage roof, the inner leaf picks up the main house roof.

That's the old front door to the house, it's just to the right of the pillar the new lintel would bear on.

Would I be right in thinking I can just use similar size concrete lintels to those used for the original front door for the new opening as it is essentially supporting the exact same loads the new opening will support?

Is there a better type of lintel to use than a pcc for this job?

Thanks
Chris.

 

[George_engineer]

Its borderline but I don't like using concrete lintels - there is no masonry above to make it composite (although the timber wall plate will spread the load, that is not what they are supposed to be doing) so I'd be looking at either a small steel or a flitch beam.

Changes to load bearing walls is a building regs thing so they may want an engineer to spec something anyway.

 

[thomp1983]

Building inspector is aware of the changes and will inspect at the appropriate stages, he thinks a standard off the shelf size lintel will suffice I just need to provide the specs to him of what I'll use and how I propose to do it and then he'll agree or disagree.

So I just need to decide what size loads are involved and type of lintel will meet those loads which is where I'm hoping you guys can help.

Thanks
Chris

 

[SpecialK]

Catnic will spec it for you if you contact them?

 

[stuart45]

You need a non composite lintel if you want to use concrete.

 

[thomp1983]

I don't have to use concrete just thought as that's what's already there for the door opening it would be equally suitable for the new opening as they are similar in size.

Thanks
Chris

 

[thomp1983]

Catnic will spec it for you if you contact them?

So I decided to use catnic's scheduling service as you advised.

They needed me to provide a scale drawing of the joist sizes and layout and some information about the roof construction and came back suggesting I use 2x BHD100 lintels as shown below.

So that was fairly straightforward just needed a few hours with a tape and some pen and paper.

My next question is should I insulate inside the lintel before fitting, thinking the biggest piece of celotex I can get in there?

Thanks
Chris