Splayed Bay Window Lintel

[haythorn_1]

I have 2 double height splayed bay windows that I will need to install 4 lintels. Wall construction is brick and block with 150mm cavity.

 

Is there any suggestion on the best lintel to use? I see catnic and others can make a custom lintel to order with posts, but they seem quite expensive.

 

There's a house being renovated on my street currently that has just used a steel plate cut to the shape, with no posts. Seems much simpler although I imagine is a significant thermal bridge.

[joe90]

With my splayed windows I use concrete lintels in the inner block skin and brick arches in the outer with no lintel, as your outers are bays arches may not do, why not use concrete lintels and cut bricks as slips on the outside (this is what I did with my patio doors.

[haythorn_1]

I’m not sure how concrete lintels would work, can you get them made to the shape of the bay?

 

my bay design doesn’t have the brick pillars that you sometimes see, which I guess you could then use normal straight lintels.

[Mr Punter]

It may work with bay poles.  I think you should ask your SE what they suggest as sometimes the bays are structural.

[joe90]

Does it not depend If the wall above the bay is also curved or straight (bay having a roof) ?

[haythorn_1]

Looks like this if it helps.

[haythorn_1]

9 hours ago, Mr Punter said:

It may work with bay poles.  I think you should ask your SE what they suggest as sometimes the bays are structural.

thanks. Will ask my SE.

 

I think it will be a lot of weight.

[Mr Punter]

I think this will be a big thermal bridge and could cost several thousand.  Better to put work in at the design stage to see the best solution.

[joe90]

24 minutes ago, Mr Punter said:

think this will be a big thermal bridge

Not if any insulation is carried around the bay surely, the cheeks look thin to give a decent cavity tho 

[Mr Punter]

13 minutes ago, joe90 said:

Not if any insulation is carried around the bay surely, the cheeks look thin to give a decent cavity tho 

 

I think this will need a hefty amount of steel above the ground floor windows to support both leaves of wall and posts to support the corners.  They will bridge the 2 leaves.  It may be that the upper part is in timber frame with cladding, which would help.  Either way it needs properly designing.

[joe90]

9 minutes ago, Mr Punter said:

Either way it needs properly designing.

👍

[Brickie]

Is it not hanging tiles on the bays?

[haythorn_1]

2 hours ago, Brickie said:

Is it not hanging tiles on the bays?

Yes it is

[Gus Potter]

22 hours ago, haythorn_1 said:

Will ask my SE.

Please do but a few general comments from me.

 

On 09/10/2024 at 20:43, haythorn_1 said:

I have 2 double height splayed bay windows that I will need to install 4 lintels. Wall construction is brick and block with 150mm cavity.

 

Is there any suggestion on the best lintel to use? I see catnic and others can make a custom lintel to order with posts, but they seem quite expensive.

 

There's a house being renovated on my street currently that has just used a steel plate cut to the shape, with no posts. Seems much simpler although I imagine is a significant thermal bridge.

 

22 hours ago, haythorn_1 said:

Looks like this if it helps.

For all @haythorn_1 photo is massively helpfull.

 

Big caveat but it looks like the roof loads are carried by the walls at the sides (standard girder truss arrangement for a peen end). I'm assuming the first floor loads are also carried by other elements and thus don't load the structure above the windows. You seem to have what is akin to a bit of light walling (even if mansard tiled the extra load is not large in comparison to roof and floor loads )above the windows and that is it.

 

Now what kind of windows are you installing? Are they timber, say hardwood, aluminium or pvc. Each different types are able to support loads from above if you beef up the mullions or use bay poles.

 

If hardwood you can just thicken every second  the mullion often, a lot of hard wood conservatory companies adopt this principle..and no special lintels required.. good for mitigating thermal bridging. With aluminium you can use a stiffening vertical plate. Pvc windows take a bit more effort as plastic bends like fury.

 

Some bespoke Catnic lintels may cost you £ 2.0k delivered.. they pull your trousers down! Get an SE and pay £300.00 for a consultation and say another £500.00 for a specification.. even if a little more you'll save money on the materials and labour costs etc.

 

 

 

[haythorn_1]

Thanks @Gus Potter Very useful.

 

Plan for windows is triple glazed aluclad - so they will be quite heavy!