Beams and Lintols

[Georgie73]

Hi

I've submitted some drawing to the building control for various works. They have now come back and asked for engineers calculations for structural beams and lintols.

I don't have any structural beams going in (I'm not having any walls taken out).

I am having a doorway created through the hallway wall. Also I am having a window opening made wider. Do I need engineers calculations for new concrete lintols for window openings?

Many thanks
George73

 

[garyo]

Did you detail the doorway/window lintels as off-the-shelf Catnics or equivalent - normally that would satisfy them - e.g. "Catnic CG 50/100 x 1200mm" for the doorway, and similar for the window, or "prestressed concrete lintel 100mm x 65mm x 2100mm" etc

 

[Georgie73]

Thank you Garyo - no, I hadn't list the lintels. I've just emailed informing of the off-the-shelf Catnics etc.

Many thanks and fingers crossed building control will be happy.

 

[Georgie73]

Thank you Garyo - no, I hadn't list the lintels. I've just emailed informing of the off-the-shelf Catnics etc.
Many thanks and fingers crossed building control will be happy.

Update: Council are happy with the Catnics etc. Thanks Garyo - you have probably saved me a small fortune on getting unnecessary engineers calculations.

 

[garyo]

Update: Council are happy with the Catnics etc. Thanks Garyo - you have probably saved me a small fortune on getting unnecessary engineers calculations.

Good stuff. Did you tell them the exact lintel you intended using in each place, or just say "off the shelf" ?

 

[Doggit]

Add 300mm to any opening (150mm support required at wither side of the opening), and if you can buy it off the shelf, then it should be sufficient for the job. It's when you can't buy it off the shelf that you have to start getting calcs done. BC are just making sure that you're actually going to use a lintel, as a lot of double glazers work on the assumption that it's not their job to do lintels, and they just change the window over regardless of whether there's sufficient support or not.

 

[tony1851]

Did you detail the doorway/window lintels as off-the-shelf Catnics or equivalent - normally that would satisfy them - e.g. "Catnic CG 50/100 x 1200mm" for the doorway, and similar for the window, or "prestressed concrete lintel 100mm x 65mm x 2100mm" etc

One would hope you are not using a 100 x 65 x 2100 prestressed concrete lintel for widening a window opening!

 

[Doggit]

Just how wide are you making the window opening, and is it a solid brick wall, or a cavity construction. Can we assume you know how to support the wall above the window (inside and out) when you widen it.

 

[garyo]

One would hope you are not using a 100 x 65 x 2100 prestressed concrete lintel for widening a window opening!

I was just copy/pasting any old stuff from a Condell site. I did wonder why they made such a wide/short lintel? Presumably to cut up on site or something?

 

[Georgie73]

Not to worry about the lintels now. I spoke with the planning officer and he advised I would be better off with the steels and the engineer calculations. He said CATs can fail.

 

[tony1851]

You reported that the council had said they were happy with Catnics?

 

[noseall]

Add 300mm to any opening (150mm support required at wither side of the opening), and if you can buy it off the shelf, then it should be sufficient for the job.

Not always that simple (wish it was).
Occasionally an opening requires a more sturdy version of a pressed steel lintel and that is why they are graded, i.e. SD, HD, XHD (standard duty, heavy duty, extra heavy duty etc). We had a set of drawings that showed a standard duty lintel on the plan. However, when I read through the engineers notes, he had specified a XHD fella. Always read the sticker on the lintel and always get the BCO to look at the sticker whilst the lintel is exposed. It is difficult to get retrospective approval of a specific XHD lintel as all that is visible is the steel edge, once masonry is built. Architects eh.

Its the ground floor window in this image if anyone is interested.

Untitled

• noseall
• 20 Nov 2014
• 1

 

[Nakajo]

If you're taking structural advice from a planning officer, you've got serious problems.

 

[Georgie73]

Yes, they said they were. However, when the same person came out, he said the catnics were expensive and that I would be better off getting steels and proper calcs. He also said people make mistakes by putting in the wrong sizes.

The other thing is, I've amended my drawings and am having a 4 panel bi-fold door put in on the downstairs and he mentioned it would need two steels joined together.

 

[tony1851]

he said the catnics were expensive and that I would be better off getting steels and proper calcs. He also said people make mistakes by putting in the wrong sizes.

The other thing is, I've amended my drawings and am having a 4 panel bi-fold door put in on the downstairs and he mentioned it would need two steels joined together.

It's not up to him to decide how you build it.