Lintel/beam ballpark size for extension.

[Deluks]

What would be the best way to support an upstairs, rear solid 9" wall (3 bed semi)
Looking to extend out, currently have patio doors in a 1.9m opening.

Looking to extend the opening to 2.6m.

There would be min of 400mm brickwork left at either end and lateral support from internal walls beyond this.

So will be looking to support: the wall above (with a decent sized window in the middle of it) and obviously the bedroom floor joists and relevant roof load above, but also whatever load the new flat roof wallplate/bearer will add (it will extend beyond the new opening either side, so probably not a lot)

I would rather the beam stays within the dimensions of the current floor joists, they about about 170 deep.


I don't think a catnic would work, so would a 152 deep UC or dual bolted PF channels be a good option?

The standard welded plate onto a beam probably wouldn't be necessary as there would be no need to conceal the beam externally, it would be hidden within the flat roof structure.

 

[foxhole]

Needs eng calcs.

 

[^woody^]

Use an IG lintel. No calcs required.

 

[Dereekoo]

Use an IG lintel. No calcs required.

Wow a lintel that will take any loading

 

[^woody^]

Wow a lintel that will take any loading

Yeah, a lintel of any given size will take the load it was designed to take for the size opening it was designed for.

 

[Dereekoo]

Yeah, a lintel of any given size will take the load it was designed to take for the size opening it was designed for.

It will take the load it was designed for, all you have to do is calculate the load that it is going to take then?

 

[^woody^]

No. Standard lintels are designed for standard domestic loading, so will typically take the wall, floor and roof above it no problem and no calcs.

 

[Dereekoo]

No. Standard lintels are designed for standard domestic loading, so will typically take the wall, floor and roof above it no problem and no calcs.

Brill

 

[noseall]

No. Standard lintels are designed for standard domestic loading, so will typically take the wall, floor and roof above it no problem and no calcs.

Which duty? Standard, heavy duty or XHD? Odd that they make different ones. Perhaps an SE could instruct?

 

[^woody^]

Which duty? Standard, heavy duty or XHD? Odd that they make different ones. Perhaps an SE could instruct?

Standard unless it's a non-standard situation!

An additional load from an extension roof may be non-standard so the lintel could be uprated, and say, a point load somewhere or some really additional loads may need a xHD.

Still no SE required, but someone does need to have a bit of nous to decide. But the key thing is that building control won't ask for any calcs, like they don't ask for calcs for every single lintel you put in over a door or window on builds.

 

[Deluks]

I will definitely be getting calcs for this, I just thought I'd see what those with more experience have used in similar situations.
I'm mentally working out how to build this and taking notes. Still in the planning stages.

These IG lintels are quite pricey, and more so as you move up the loading range, I'd be happier just 'sticking an RSJ in' as they are more readily available and unused/'wife changed her mind' ones can often be picked up for peanuts on eBay (yes, I am a cheapskate!)

 

[^woody^]

Experience says that the whole point of using a lintel is that it removes the cost of an engineer, padstones, infilling, painting, bolting and often lifting the monster that the engineer designs.

50% less if cost is a factor

 

[Dereekoo]

.

Still no SE required, but someone does need to have a bit of nous to decide.

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)

 

[thomp1983]

Both catnic and birtley offer free scheduling services where they'll spec the lintels for you if you provide the information they request

 

[freddiemercurystwin]

But only if there is no ambiguity in what is being supported, that is the (limited) technical staff can interpret and measure the loadings required.