steel and brickwork span

[Sarah150]

i am building an extension 8.5 wide. Joining a lean to extension. The idea was to have bifolds with a steel which is 205 by 156 25kg sitting on inside leaf, plate on bottom for bricks on outside, this issingle storey, vaulted roof lean to.

However the bifolds needed to start near the old brickwork to make the rooms work,

The brickies keyed in on the outer leaf,then used a profile on the inner leaf. They had built 450mm, one block, brickwork to rest the beam on, SE, said 300 could be used, which would have worked. So BC came out. SE wouldn’t answer query and report useless.

When BC came they said minimum of 450 needed, would have preferred 650! They let it go at 450. I can’t understsnd why, is that normal.

I can t understand why I couldn’t have 300mm for the steel to sit on. Upshot I had to reduce my bifolds nd had to have 450 on one side and a silly 100 th other.
Is it that 300 would have been unstable for the steel? Brickies put extra ties in between inside and outer and said one block piled on top was better than cutting them.

So... if I hadn’t had a steel could I have had a 300 wall there, is it the steel which is the issue meaning I need a bigger span of brickwork?

Confused

 

[Notch7]

I wouldve thought the starting point would be to ask the engineer what you want to achieve and he can then tell you what can be done and what the cost implication will be.

Did the plan drawer not consider your requirements for bifold size etc?

The pier size may be to do with lateral restraint rather than bearing for the lintel steels. In which case maybe steel goalposts may a solution?

 

[John D v2.0]

Sounds like your designer has fallen short. Was the SE contracted to input into the building design or just design the mechanism of support? If they were just calculating beams, maybe they can't be blamed, but if the SE and designer were supposed to work together they would have resolved this in advance. You could possibly support the beam off the existing house brickwork via a padstone (cheap enough if possible), or fix a channel to the wall and sit it on a big piece of concrete which would be expensive and difficult. A decent SE could probably think of more ways that are better. Is there another storey above or just a roof?

 

[tony1851]

As Notch has said, it's an issue of lateral stability of the extension as a whole, not bearing for the steel beam.
(If just supporting a few rows of bricks and lean-to roof, a padstone 200 long would easily suffice).

 

[Sarah150]

Thanks, single story, and a padstone in place, but BC still said has to be 450 wall, they didn’t key into old building or inner leaf, they put a profile on, guess that wasn’t stable enough.

Thanks everyone