Cracks appearing after 5m RSJ installation and bi-folds

[ClydeB]

I've had a set of bi-folds installed which required a 5m RSj to be installed too.
The RSJ has been installed onto two pieces of cut steel and not padstones due to my exposed brick outer wall.

The RSJ over it's length has in excess of 10mm difference in install height and the RSJ is not level. There is approximately 10mm of silicone at one end above the bi-folds and it's practically touching at the other.

I have a stud wall upstairs which runs perpendicular and it meets the RSJ at the mid-point of it's length. The fitted wardrobes upstairs now has a ~6mm gap above them and the upstairs coving running along it's length has separated from the upstairs ceiling with a similar gap present.

The company installing the bi-folds insists that this is normal movement, but I believe that the unlevel RSJ has caused the upstairs joists to drop and therefore put a strain on the stud wall and it's cracking due to the difference in the install heights of each end of the RSJ.

No additional packing above the RSJ was used and it appears that the installation company is insisting this is acceptable. Is this right?

What is the height/level tolerance in the installation of a 5m RSJ?
If there is a difference in install heights at the ends would you expect that there would be some packing on the inside skin above the RSJ to make the supported joists and bricks level once again?
The outside skin of the house needed packing (builder used wood and pushed in a little cement) as cracks were creeping up and across, but nothing was used inside. Would you have used wood or slate to achieve this?

I would love to get your feedback as this issue has been going on for about 6 months and the install company is not accepting liability or offering to rectify the issue as I see it.

The pictures can be found here and I can add more if you ask for specific:

https://www.dropbox.com/sh/0dv7dyn3ok4arpr/AAAGX_g60dBc19zZvHUUY5nMa?dl=0

Many thanks,
Clyde

 

[Notch7]

No additional packing above the RSJ was used and it appears that the installation company is insisting this is acceptable. Is this right?

No, steels have to be packed underneath, on padstone and /or on top to stop brickwork dropping.

Its difficult to prevent a bit of cracking. Sometimes the acrows can be over tightened and cause the brickwork to rise and create cracks.

The fact the steel is a bit out level isnt an issue in itself -steels are difficult to get dead level, they are often a tad out.

 

[John D v2.0]

Above the steel should have been fairly dry mix mortar to prevent it dropping. We had 2 walls on a corner knocked out and steels and a pillar put in on a new Foundation, and the room above had minor cracking all over but nothing worrying. It's impossible to prevent settlement completely but in your case it sounds excessive.

 

[wessex101]

Your description does sound like a poor quality installation. Someone who tries to pack above a beam with timber clearly hasn't got a clue what they are doing so it calls in to question the competency of everything else.

However, if inadequate packing has caused the wall above to drop you would expect to see cracking in the wall itself, rather than just around the edge of the ceiling. If you suspect that the floor joists have dropped you would need to establish how the joist ends are supported. Are they built in to the wall above the beam or do they sit directly in/on the beam?

 

[^woody^]

There should be no cracking and no movement.

• The steel is designed to deflect within limits so as not to cause cracking once loaded.
• The opening is propped so as not to move the structure above.
• The steel is put in so as not to allow the structure above to move downwards.

There is no such thing as "normal movement" that causes cracking. That's abnormal movement.

 

[tony1851]

All steel beams deflect, the question is: when does it become unacceptable.? The design codes give quantitative limits for deflection but, except when dealing with live loads, much is left to the discretion of the engineer who specified the beam.
Having said that, the OP doesn't mention if the steel beam was actually specified by a SE, or if the window-installers have just put any old beam in?
Would be interesting to know the section-size of the beam.

 

[^woody^]

* deflection is an allowance for finishes, and not the walls and structure above cracking and moving.

 

[wessex101]

From my experience engineers tend to over specify steel beams over sliding/folding doors specifically to reduce deflection which tends to adversely affect the operation of the doors.

From the OP's description it sounds as though they just loaded the beam and then tried to deal with the cracking after the beam started to deflect. Depending how much deflection had been factored in to the design perhaps they should have packed the beam to induce the deflection before they released the props.

 

[ClydeB]

@wessex101 The beams sit directly onto the beam itself. So due to the slant on the RSJ/I-beam I feel that the joists are no longer level themselves and over the entire length of the
beam the whole of upstairs has dropped by over 10mm. As you can see there are cracks in the back inner walls as well These are plasterboard with a skim, but have cracks in them.

I've uploaded more files to the link in the initial post.

@Notch7 I understand that maybe being 100% level could be an issue, but wouldn't you expect the wall above to be packed in order to eliminate the slant of over 10mm?
Also one of the files uploaded to this post you can see that the RSJ sits on top of a piece of steel and then on the wall itself. No padstone due to exposed brickwork outside.

Just to confirm I had my painter and decorator in a month or two before work started to do a little minor hairline crack fixes which occurred due to paint/filler shrinkage.
This was the first touch-up since we painted when we moved in 7 years ago. So the huge gaps 5mm or more isn't expected.

@John D v2.0 Thank you for confirming these are excessive and I'm not "Chicken Little" and crying wolf.

Clyde

 

[tony1851]

* deflection is an allowance for finishes, and not the walls and structure above cracking and moving.

In other words, it's a servicability issue and not a structural issue.
The limit for deflection under live load is usually span/360 to avoid cracking of finishes, but deflection under dead load (ie walls/floors/roofetc)
depends on the state of the structure above the beam and is often unquantifiable.

 

[ClydeB]

From my experience engineers tend to over specify steel beams over sliding/folding doors specifically to reduce deflection which tends to adversely affect the operation of the doors.

From the OP's description it sounds as though they just loaded the beam and then tried to deal with the cracking after the beam started to deflect. Depending how much deflection had been factored in to the design perhaps they should have packed the beam to induce the deflection before they released the props.

I'm no engineer but I doubt the beam has deflected (at all and definitly not 5mm or more) as the steel weighed over half a tonne and each part of the steel is 20mm thick

 

[tony1851]

I'm no engineer but I doubt the beam has deflected as the steel weighed over half a tonne and each part of the steel is 20mm thick

What is the actual section-size of the beam, ie width of flange and overall depth?

 

[wessex101]

Am I being a bit thick here? From the new photos the beam seems to be sitting under the outer leaf of the wall. What's supporting the inner leaf? Is that a concrete floor slab above?

 

[ClydeB]

I appreciate everyone's help - thank you.

The size was approximately 5m long, bi-folds are 4.7m.
The measurement of the top and bottom of the I is 20mm thick.
Measurement of the bottom and top lip to the centre is approx 90mm I assume the outer top and bottom lip is the same, but it's been filled.
The height and total width measurement of the beam is 220mm.

 

[ClydeB]

Am I being a bit thick here? From the new photos the beam seems to be sitting under the outer leaf of the wall. What's supporting the inner leaf? Is that a concrete floor slab above?

The upper floor is just wooden.
I guess that the inner leaf is partially supported by the I beam?

You can see a ridge in the concrete blocks of the inner leaf and I believe that ridge shows where the original pier wall supported them.