Is the beam too big for purpose

[Sophiae]

2 hours ago, George said:

I don't think they have. In the summation there is only 350mm of block. 

 

I agree with @Gus Potter that things could have been made tighter but based on the information in the thread, it's not as though the SE has gone completely wild. Builders always say beams are oversized. 

 

A lower depth beam with the same stiffness would have required an even heavier beam - this would be more steel weight and potentially splice designs etc. So from the SE's perspective, more cost to him. The most common competing interests are weight/cost (all things being equal a deeper beam is lighter), depth of beam and speed (allow for over-deign based on limited information). In the absence of other instructions the SE went with cost

So what does sheet 5 mean? Where did he get those from? 

Edited May 22, 2023 by Sophiae
Attaching the sheet in question

[TonyT]

3 hours ago, Sophiae said:

I agreed for them to be paid extra but the amount was over priced. I know it was a way to stop me from agreeing because they simply saw I am a small woman and can easily live under a 190 height. 
 

To be honest it wasn’t their fault, neither was mine, but I am the one spending money for other people’s fault. 

but how could they have not spotted the design fault before purchasing the steel?.

 

now the project is on hold because they decided to cast the pad stone on site rather than a precast as per the SE’s instructions so BCO said he needs to get an email of approval. 
the SE said he can’t come on site to inspect the work so he wants them to break the supporting sides and rebuild again to his specs. 
 

someone is taking the **** out me here. 
 

 

It’s not the builders job to check the SE design to see if it’s right, afraid we don’t know how the architect, SE, project manager have been appointed to understand this relationship.

[Sophiae]

On 22/05/2023 at 19:47, TonyT said:

It’s not the builders job to check the SE design to see if it’s right, afraid we don’t know how the architect, SE, project manager have been appointed to understand this relationship.

I completely agree. 
the builders were subcontracted from the management company. Initially the company wanted to install timber instead of steel. Building regs said no. They brought a SE design and I then said no and went to a 3rd party and paid myself. 
then all hell broke loose. 
this new team of builders are their own company, so their response was that they are not engineers to comment on the design and calculations, they stated the facts when the steel arrived and the SE was confident it would still give up over 2m head height till he discovered it was just 190. 

[TonyT]

Sounds a confusing relationship to determine clear ownership of the problem.

 

 

[Sophiae]

7 minutes ago, TonyT said:

Sounds a confusing relationship to determine clear ownership of the problem.

 

 

The design is the problem. The SE decided to ignore my presence in this relationship and make his choice. He picked what he said was “the cheapest” steel for me as he knew I was on a tight budget. 
No consult, no information, no warning of long span risks on head height, nothing. 
And now he is making us take down this monster because he is unsatisfied with the 7N blocks sitting underneath. he said he couldn’t tell from the pix. I asked him to please come to site as I already asked him before the beam arrived to make sure all measurements are in place. But he said he can’t. And then he changed his mind and wasting my time. 

[SteamyTea]

On 20/05/2023 at 14:02, Sophiae said:

A reputable structural engineer was assigned to design and calculate replace a load bearing wall with steel beam along with another beam for the new wall to hold the bifold doors. 

Was he employed by the Architect?

That should be the person who picks up this sort of nonsense.

I am pretty short, but 1.9m is only 0.2m above my head.

[TonyT]

43 minutes ago, Sophiae said:

The design is the problem. The SE decided to ignore my presence in this relationship and make his choice. He picked what he said was “the cheapest” steel for me as he knew I was on a tight budget. 
No consult, no information, no warning of long span risks on head height, nothing. 
And now he is making us take down this monster because he is unsatisfied with the 7N blocks sitting underneath. he said he couldn’t tell from the pix. I asked him to please come to site as I already asked him before the beam arrived to make sure all measurements are in place. But he said he can’t. And then he changed his mind and wasting my time. 

 I think the design is part of the problem, the client making certain decisions bringing in a third party adds to the confusion, appreciate that’s not what you may not want  to hear.

 

Didn’t the SE info say

it needed pad stones, so you can understand his reluctance if it’s then sitting on blocks not to the design..

 

How are you asking the SE, are you going through the Architect or direct to the SE.

 

is the architect instructing the SE or working independent from the architect?

[George]

6 hours ago, Sophiae said:

The SE attended and made a full survey before we sat down and talked about my desires and what was possible. 
He took full measurements and I made sure he knew there will be no near or far future to go up with the build, not even a loft conversion. There are few mobility issues, including steps, stairs, all dangerous around my son and I will not compromise his safety for more unneeded space. 
 

so are you saying that the extra block and brick and first floor dead and live loads all part of the appropriate calculations despite they don’t exist? 

Yeah - the calculations just include their 'standard' loading that may or may not be used. On sheet 7 the actual loading in used in the beam design are listed - none of those are beam & block or first floor. Only roof and 350mm of blockwork. 

The 7.28kN/m & the 5.9kN/m follow through to the calculation in the pdf.  

[Sophiae]

5 hours ago, George said:

Yeah - the calculations just include their 'standard' loading that may or may not be used. On sheet 7 the actual loading in used in the beam design are listed - none of those are beam & block or first floor. Only roof and 350mm of blockwork. 

The 7.28kN/m & the 5.9kN/m follow through to the calculation in the pdf.  

What does it mean? 
I trust you have gone through the thread, so reading all this, does it justify the design? 
 

[Sophiae]

8 hours ago, SteamyTea said:

Was he employed by the Architect?

That should be the person who picks up this sort of nonsense.

I am pretty short, but 1.9m is only 0.2m above my head.

No, employed by me. Which is why I am picking up the nonsense. 

[Sophiae]

On 22/05/2023 at 21:07, TonyT said:

 I think the design is part of the problem, the client making certain decisions bringing in a third party adds to the confusion, appreciate that’s not what you may not want  to hear.

 

Didn’t the SE info say

it needed pad stones, so you can understand his reluctance if it’s then sitting on blocks not to the design..

 

How are you asking the SE, are you going through the Architect or direct to the SE.

 

is the architect instructing the SE or working independent from the architect?

So the client hasn’t said anything but to follow the SE’s instructions. The SE was asked by the builders whether the side supporting walls need to come down and rebuilt or does he find them adequate. He said they were good enough and asked for a pre cast 800mm pad-stone. That doesn’t exist, and it’s extremely heavy to lift, so how could the builders do it.

When questioned, he said “I wrote or lintel” I said but there is no 800mm lintel either. Why couldn’t you just be clearer when you wrote your instructions? 
 

he made notes about digging for foundation, then he said there was no need and we can use the existing one. 
 

something doesn’t add up with this SE. I don’t know what is it. 

[Sophiae]

5 hours ago, George said:

Yeah - the calculations just include their 'standard' loading that may or may not be used. On sheet 7 the actual loading in used in the beam design are listed - none of those are beam & block or first floor. Only roof and 350mm of blockwork. 

The 7.28kN/m & the 5.9kN/m follow through to the calculation in the pdf.  

What do these represent? The deal and live weights on the beam. How did he come up with these numbers?

[TonyT]

You buy an oversize lintel and cut it down to the required length

[BadgerBadger]

I'm not sure I fully understand the contractual relationships between yourself, builder, SE - or if you have an architect? Who is responsible for the design?

 

Traditionally an architect would work liaise with the SE. The SE would calculate beam sizes etc. from a preliminary drawing and the architect would then work those beams back into the design.  It's at this point the architect would hopefully say "that beam is impacting head space too much" and work with the SE to find a more acceptable solution.

[dpmiller]

who or what is the management company? Is this a project manager or is it a rented property?

[Sophiae]

52 minutes ago, BadgerBadger said:

I'm not sure I fully understand the contractual relationships between yourself, builder, SE - or if you have an architect? Who is responsible for the design?

 

Traditionally an architect would work liaise with the SE. The SE would calculate beam sizes etc. from a preliminary drawing and the architect would then work those beams back into the design.  It's at this point the architect would hopefully say "that beam is impacting head space too much" and work with the SE to find a more acceptable solution.

I am the owner. There is no contractual relationship between the Architect and the SE. 
I employed both at different stages separately. 
Once the SE trimmed the 3m wall down to 110cm, I just worked off his instructions when it came to the walls. After all he’s the expert. 
And now everything is on hold when the SE tried to cover up for his mistakes. He wants us to take the steel down, rebuild those 2 side support walls and then bring it up. This is when I said stop and let me investigate why did we get here, and why did he change his mind about the support walls.

And here we are. 

 

 

[George]

3 hours ago, Sophiae said:

What do these represent? The deal and live weights on the beam. How did he come up with these numbers?

They are derived from the standard list of loads on the previous pages. 

 

They look about right for loading on a domestic beam.

 

[SteamyTea]

10 minutes ago, Sophiae said:

This is when I said stop and let me investigate why did we get here

That was the right thing to do.  It may add some time now, but the beam may be in place for 100 years.

[Sophiae]

17 minutes ago, dpmiller said:

who or what is the management company? Is this a project manager or is it a rented property?

This was last year property maintenance services company. 
They provided management services to the build, so property owners didn’t have to worry about going through all of this.

 

I’m a single parent to a disabled child. I live far from the site and I work in between to provide for us. I had and still have no knowledge of the different elements except from what I’ve read and learned these last couple of weeks with the blunder of the beam. 
I don’t have any money anymore to pay anyone as it was all spent last year and with all prices nearly doubled, I needed to make choices between working extra shifts to pay someone to communicate between people and overlook the builders, and buying materials that are now needed to adhere to new building regs (insulation). And other materials needed to complete the external shell of the extension so that it is closed and we can move in to save my rent money to carry on with the rest of the work whilst living there. 
 

I can’t stress enough that I am Neurodiverse (on the spectrum) and this has it’s own challenges. 

[Sophiae]

16 minutes ago, George said:

They are derived from the standard list of loads on the previous pages. 

 

They look about right for loading on a domestic beam.

 

But are they right for my build? The existing build is a single story bungalow with an accessible attic with nothing in the but roof on top. No conversion or intension to in the near or far future. 

[George]

32 minutes ago, Sophiae said:

But are they right for my build? The existing build is a single story bungalow with an accessible attic with nothing in the but roof on top. No conversion or intension to in the near or far future. 

I can't be definite on what loading is correct based on an internet forum thread - but there doesn't appear to be any arithmetical mistake in their work and their assumptions look reasonable. They have only allowed for roof loads from the main roof and the extension roof and a small amount of blockwork.

 

It is the beam span which is the primary cause for a large beam - stresses in a beam increase as a square of the span. And while beams can reduce these stresses in a cubic relationship, they can only do that by increasing in depth. 

 

I do feel for you and the engineer should have prioritised head room over steel weight (although as others have pointed out this is not usually entirely the role of the engineer), but if you are looking for any other significant mistakes or omissions then from the information posted I do not see any.

[TonyT]

It has to take the weight of a proportion of the roof and transfer this load/weight elsewhere.

 

I think if you posted some before and after floor plans with no personal information and a brief the forum may be able to advise you on how to move forward.

some idea of type of finishing, ie low medium high specification, what other works may be required, pluming electrical altering heating system, ground works, drainage etc

 

all the best

[Sparrowhawk]

1 hour ago, Sophiae said:

I am the owner. There is no contractual relationship between the Architect and the SE. 
I employed both at different stages separately.

Then, and I know it won't be what you want to hear, the responsibility for the lack of headroom lies with you.

 

It would have been nice for all if the structural engineer had sense-checked this, or the builders before they put it up; but they didn't and in the end whoever is project managing is responsible.

 

(There's some depressing threads on this forum where people signed off on their window orders trusting the measurements in the order were correct - and even though the window company made the mistake, the responsibility lies with the one who signed).

None of that helps now, save to say that apportioning blame to anyone including yourself isn't going to be helpful.

 

People on this forum will be able to help you come up with a solution. We're rooting for you.

 

And as someone with neurodiverse siblings and a bit that way myself: most forum members can't/won't synthesise a 3 page thread in the way you (or I) do. They're dipping in amongst their busy lives. So to get the best help, start a new thread with floorplans, photos and a clear statement of one or two problems/outcomes you need help with. Post a link to it in this thread so ppl can jump across.

 

Something that I haven't seen mentioned yet: the joist is going to need fireproofing, which IIRC is a minimum of 25mm plasterboard around it (someone here please correct me). So that needs taking into account re headroom too.

[Lofty718]

Using a property managment/maintenence company for an extension was your initial mistake.

 

Should of found an actual builder on recommendation. Decent builder won't want to build something that is restricted in height or doesn't work well for the client and would of looked for a work around.

 

You seem pretty on the ball and sounds like you could of managed a builder well rather than leaving it to some shoddy company. You will get this resolved soon and once done and dusted will all be worth it.

Edited May 23, 2023 by Lofty718

[jfb]

31 minutes ago, Sparrowhawk said:

is going to need fireproofing, which IIRC is a minimum of 25mm plasterboard

Pretty sure you can get fire rated plasterboard to bring that down. It’s the pink plasterboard I think.