Lintel/beam ballpark size for extension.

[^woody^]

When you say nous is this from someone with wide experience who can select based on his past knowledge/experience or some layman/DIYer with a bit of nous who can calculate what the loads are and then make an informed decision on the selection of a standard, HD or XHD lintel after consulting any brochures that IG offers (or advice from IG technical dept)

As good as he is in his own area of expertise (security, social interaction), my Spaniel couldn't flick open an IG brochure with his nose and wag his tail when he sees a lintel he likes.

So, my happy furry mate has no nous for structural alterations, but probably has nous for sniffing out £3m worth of crack and finding ex-pheasants.

The whole point of lintels is that they have already been worked out - the wall type, the loads, the load scenario, the exposure etc. So you don't need [to pay] someone to work that out for you. All that remains is to pick the appropriate one for the specific situation, and that's where nous comes in. Some may have it, and then it's gravy, but for Spaniels and kennel knock-throughs, yes someone with the required nous would need to make the selection.

If someone is just putting a lintel in a wall, in a typical house with typical room sizes, and the lintel will just be holding up a wall, a roof and maybe a floor, then if there is a lintel for the span, and it's the right type for the situation, then it's most likely the lintel will do.

Many people think large spans require a steel beam but that's not the case.

 

[stuart45]

Many people think large spans require a steel beam but that's not the case.

Just as well, or there'd be a lot of 4.8 catnics laying around.

 

[robinbanks]

sniffing out £3m worth of crack

And what do you do with it when he finds it?

Many people think large spans require a steel beam but that's not the case

Indeed; "if it's long enough it's strong enough"

Usually

 

[Deluks]

Looking at the IG lintel profile, (Ibeam-2C) it appears that a brickwork course is required on the bottom flange, which carries up to support the outer edges of the wall above the top flange (as the top flange isn't wide enough to support the full width)
I was expecting to be able to bolt a timber either side to pick up the bedroom floor on one side, and the extension flat roof on the other side.

Now thinking of using a pair of 178x102's, and battening out the ceiling and dropping it by 22mm.

This would ensure that the beam would be buried within the height of the 170mm joists, and allow me to nibble a bit of height from the extension roof, whilst keeping the ceiling flush between the old and new.

I have a 3m 178 knocking about in the garage, so that helps keeps the costs down in that respect. But would BC still insist on calcs for a beam that's blatantly overspecced?