Cracks upstairs when putting in a steel beam

Paul_Mc1988

Currently getting an rsj put in the house and the wall is down and the ceiling across. There is a few small cracks upstairs showing is this normal?

BryanF

What has your structural engineer stated?
Did he inspect the temporary design?

Paul_Mc1988

The builder deals with him I'm just asking a quick query for peace of mind. The cracks are minuscule and he says the floor drops a millimetre or two when the wall come out and when the RSJ goes in and gets acroed back up it puts the milimeter back in

Gumbo

Any pictures

Paul_Mc1988

kceire wrote: »

Any pictures

Wall https://imgur.com/gallery/B9iYLDR

Paul_Mc1988

Afros had to be posted 3.5 feet from the wall to get the swing on the steel. Acroed up the center piece till the steel goes in tomorrow. Where the Joyce's meet the biggest drop is the one in the middle at 5mm. How does it look. RSJ is getting inserted 7 inches to the outside wall with an L plate welded. 7inces into the internal wall at a corner section with a box steel upward piece welded.

SC024

theres a block wall sitting above them joists ?

Paul_Mc1988

SC024 wrote: »

theres a block wall sitting above them joists ?

Yeah a block wall

BryanF

Paul_Mc1988 wrote: »

The builder deals with him I'm just asking a quick query for peace of mind. The cracks are minuscule and he says the floor drops a millimetre or two when the wall come out and when the RSJ goes in and gets acroed back up it puts the milimeter back in

Why not ask the engineer. He has seen the before and after propping process or can at least, visit and see if something has settled. it’s the engineer thats best placed to comment. The forum charter precludes posters from commenting on structural matters.

Gumbo

Paul_Mc1988 wrote: »

Wall https://imgur.com/gallery/B9iYLDR

Where are those cracks relative to the propping?
I’d have the engineer view before the builder continues. There should be minimal deflection/movement.

mickdw

The fact that a solid wall overhead has moved is a bit worrying.
How was the wall overhead propped? Wall should have been propped above the work areas so that props could remain in place for the duration.
Is the overhead wall carrying roof?
Make sure the Engineer is working for you and not just there to facilitate the builders shortcuts so get asking questions directly to the Engineer. Say you are concerned and would like them to inspect immediately.

Paul_Mc1988

mickdw wrote: »

The fact that a solid wall overhead has moved is a bit worrying.
How was the wall overhead propped? Wall should have been propped above the work areas so that props could remain in place for the duration.
Is the overhead wall carrying roof?

Acroed from both sides of the existing wall that was removed.. The above wall is not supporting the roof.

Paul_Mc1988

kceire wrote: »

Where are those cracks relative to the propping?
I’d have the engineer view before the builder continues. There should be minimal deflection/movement.

Probably about 1.5 meters to the left of the centre of the wall that was removed on the floor above. I'll get him to contact in the morning. Have you ever seen anything like the above?. The opening span is only 3.4 meters

Gumbo

Paul_Mc1988 wrote: »

Probably about 1.5 meters to the left of the centre of the wall that was removed on the floor above. I'll get him to contact in the morning. Have you ever seen anything like the above?. The opening span is only 3.4 meters

Span here is irrelevant.
The way in which the temp props were done is possibly at fault but you’d have to see it in person.

mickdw

Paul_Mc1988 wrote: »

Acroed from both sides of the existing wall that was removed.. The above wall is not supporting the roof.

So the wall was in fact not propped itself at all until most of it was removed and then prop.placed under. Propping the ceiling either side is of very limited use.
The prop under will now have to be removed to put the steel in again.
I wouldn't have faith in this builder.

Calahonda52

As notedly a number of posters, this is not the way it is done.
A scaffold board on the flat, unsupported for 8 feet was never ever going to do the job.
.
Can you post pictures of the cracks.
You might consider fitting some glass tell tales across the cracks upstairs BEFORE the central acrows are removed for fitting the steel beam.
.
As for closing the cracks by jacking up the acrows.. wont happen.

You do know you need the engineer to certify this work, before the beam gets covered over so I would be taking more pictures.

kevcos

mickdw wrote: »

So the wall was in fact not propped itself at all until most of it was removed and then prop.placed under. Propping the ceiling either side is of very limited use.
The prop under will now have to be removed to put the steel in again.
I wouldn't have faith in this builder.

Why slate the builder without knowing much about the project or this part of it?
The OP may be in contract with him, an Engineer on the ground is the best to make that judgement.

OP, are the joists running perpendicular to the wall above?
If so I imagine that the intention was that the joists have been propped not only to prop the ceilings but as steel needles/strong-backs to prop the wall above.

Quicker way of doing the job, therefore cheaper, maybe thats what you procured. Putting in steel needles/strongbacks may have caused even more cracks, it would certainly have been more destructive at least.
Not textbook but not dangerous either, The wall wont collapse (from what I see).

Nonetheless, certainly have the SE pop by to inspect as other have said.

LillySV

I got a supporting wall removed in ground floor in my house 2 years ago just like you.. we have hollowcore floors so they propped the ceilings used wood and devices like in your pics, then they knocked the wall and put in the rsj all on the same day ... no cracks on the walls upstairs though. I think u need to get that engineer back for a good look to ensure all is ok

Calahonda52

kevcos wrote: »

Why slate the builder without knowing much about the project or this part of it?

.
The picture says it all.

LillySV wrote: »

I got a supporting wall removed in ground floor in my house 2 years ago just like you.. we have hollowcore floors so they propped the ceilings used wood and devices like in your pics, then they knocked the wall and put in the rsj all on the same day ... no cracks on the walls upstairs though. I think u need to get that engineer back for a good look to ensure all is ok

.
HC is a different animal to timber
Was there a wall above the join in the HC flooring?

LillySV

Calahonda52 wrote: »

.
The picture says it all.


.
HC is a different animal to timber
Was there a wall above the join in the HC flooring?

Yea there is

Paul_Mc1988

Update. Engineer reckons there is no issue. You will always get some movement when a wall goes down and the hairline crack is nothing to worry about. He'll be signing off on it so it elevates any worries I have. Thanks for the replies.

mickdw

As long as all sides are happy but there is a right and a wrong way to do things.
My Educated opinion would be that short cuts were taken here.

kevcos

mickdw wrote: »

As long as all sides are happy but there is a right and a wrong way to do things.
My Educated opinion would be that short cuts were taken here.

There's a right way to do a job, there's a wrong way and there's also a wide range of acceptable ways in between the two.

To prop the wall above joist/UB level would have involved punching acrows through the ceiling, the floor above and then needling the strongboy blades into the wall above.
All destructive works to be made good and destructive works which would likely disturb the existing structure.

Furthermore, I'd wager if you do the cals, that the existing joisting at ~400mm cc would provide greater support than say 4 strongboys at ~900mm cc.

Granted, all the above assumes that the joisting is running perpendicular to the wall; otherwise the builder is a total chancer and wants running:pac:

mickdw

kevcos wrote: »

There's a right way to do a job, there's a wrong way and there's also a wide range of acceptable ways in between the two.

To prop the wall above joist/UB level would have involved punching acrows through the ceiling, the floor above and then needling the strongboy blades into the wall above.
All destructive works to be made good and destructive works which would likely disturb the existing structure.

Furthermore, I'd wager if you do the cals, that the existing joisting at ~400mm cc would provide greater support than say 4 strongboys at ~900mm cc.

Granted, all the above assumes that the joisting is running perpendicular to the wall; otherwise the builder is a total chancer and wants running:pac:

I'd agree if you could be sure that any joists were continuous and fully built in. I'd want additional bracing locally within ceiling and I'd still prop much closer to the wall line.