What do you think of this steel beam installation 1

[Eagle42]

Hi,
Please have a look at this footage (file 2790) and photos I took behind my bath of a steel beam that was installed for a single story kitchen extension on the back of a 3 bed semi detached house. There are cracks upstairs and quite large ones above the beam in the bathroom. I'm no expert but the installation doesn't look right? Any comments advice would be greatly received

https://drive.google.com/drive/folders/1-l0xl8r4kAO_xqUIX4PHNk_ov2AEBs3Q?usp=sharing

Best

Gareth

 

[dauwerda]

Using the numbers in the calcs provided, I am coming up with a beam deflection of 8.58mm (equates to L/500 deflection ratio), not the 2.908 that is reported. Adjusting the span length to 4.7m I am coming up with a deflection of 12.29mm (equates to L/383 deflection ratio). A commonly accepted deflection ratio for masonry is limiting it to L/600 or 0.3in (7.62mm). The numbers I came up with above are well in excess of the maximum limits, so it makes sense that you are having the issues you are having.

None of what I provided above should be taken as a complete (or even correct) diagnoses of what is happening. As others have stated, you need to get a local structural engineer to the site to take a look.

 

[Eagle42]

Oh dear. I’ve written on a couple of more photos to help explain the set up. It’s a cavity wall and floor 1960s 3bed semi. The rear wall underneath the bathroom and back bedroom were knocked through . Pitched roof 15• single story.

 

[MIStructE_IRE]

Oddly enough I’ve also had the opposite happen before where walls cracked because the temporary props below were overtightened on site causing the wall to lift!

 

[Eagle42]

Hi,
I stumbled across a New photo (in the folder)of the right hand side of the beam. Any more concerns on this side? Does it matter the pad stone is over a cavity wall? Also does the beam over hang as it should?
Thanks

 

[BAretired]

Does it matter the pad stone is over a cavity wall?

I think that could be a problem.

BA

 

[Enable]

What a mess. A twin beam detail would have been silly to begin with. What was the plan? To support the brick on one half of each flange only so we can induce torsion for giggles? Your flanges would have had to be miniscule to avoid that condition. One beam makes sense but it would have had to be appropriately designed, which clearly, well...

OP this is a mess and while we can speculate and have fun looking at the failure modes, we cannot help you. You need a local structural engineer with boots on the ground. These beams likely have to be stiffened. Their supports likely so as well. Cosmetics done thereafter.

I am sorry about the botched job. That's just terrible luck. Permits should never have been issued without beam sizes indicated on the original drawing set. This is a failure every single way.

A commonly accepted deflection ratio for masonry is limiting it to L/600 or 0.3in (7.62mm). The numbers I came up with above are well in excess of the maximum limits, so it makes sense that you are having the issues you are having.

Would you still use L/600 in a retrofit application? If masonry deflected beyond its in-situ state (read: already deflected state) an additional 1/4" I feel that you are basically reconciling yourself to the fact that there will be cracking. Wouldn't you want to limit it to a max actual deflection of say 1/8" or less regardless of new-build L/X rules (to within reason)?

 

[engineering_patrol]

Oh my goodness!!!!!!

 

[Eagle42]

Hi,
Yes a structural engineer has been appointed Unfortunately I am being blamed for the cracks. see folder, I'm a pen pusher

https://drive.google.com/drive/folders/1JH6KgpwTooywC87ARqV_RVQ8bbELGtr1?usp=sharing

 

[Eagle42]

My question is would using this device cause cracking upstairs?

 

[MIStructE_IRE]

No one on here can tell you that unfortunately OP. You need a local to see it in the flesh. Personally I would probably have put in a goalpost frame in that situation since he’s removed the original stabilising shear wall. I see a brick partition wall behind the kitchen (probably 100mm) so that’s giving you some lateral stability at least.

But as everyone here has said, get a local engineer. What about the guy that did the after the fact calculations? Can he inspect for you?

 

[LittleInch]

It's now asking for a request to access those pictures?

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[dauwerda]

Enable,
I completely agree that a more stringent deflection criteria would need to be used in this situation to prevent cracking. I just know the L/600 is well established for a place to start, and even that deflection was not met based on the numbers given in the calculations.

 

[Eagle42]

Thank you very much for all of your replies. Its going through legal process so Ive decided to disable the file but when all is finished I will upload engineers finding etc and let you know the outcome. Best wishes and thanks for all the help

 

[MIStructE_IRE]

You may wish to ask for this thread to be deleted if its going legal.

Best of luck with it.

 

[Eagle42]

The beams were 152x152x23. 3.050m
254x254x73 4.620m

 

[Eagle42]

Hi,
Does a steel beam have to span an entire gap or can there be small gaps at either end. I’ve noticed that one side of my kitchen ceiling rsj is flush with the brick work on one side but there is a 100mm gap on the other ?

Best

 

[Eagle42]

https://drive.google.com/file/d/1mUkydlvu075EBKGD-5rC6akmAnHK7nrA/view?usp=drivesdk

 

[BAretired]

The beam must be long enough to span the clear opening plus adequate bearing at each end. The gaps beyond the beam can be any length, even infinite.

BA

 

[LittleInch]

I'm pretty sure in the UK you need 300mm of bearing into the wall via a "pad stone".

You seem to have the pad stone, but that doesn't look like a great wall in which to bear the load.

Check you have 300mm of bearing.

Who did the building regs check on this build??

Thinks like this are usually a hold point for the inspector to sign off.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[Eagle42]

I believe it’s 150mm bearing is required minimum.It’s being checked after being covered, no building checks were done.engineer coming, can I have a list of what he should check. Beam sizes, padstone size, connection, fire proofing...

https://drive.google.com/drive/folders/1-M6qnqC7in8F4kKe53opOg4idUPRdFtt

Thanks