Is the beam too big for purpose

[Sophiae]

Here’s his response to correct the mistake of leaving 190cm. Option 1 remove the timber plate 50mm, option 2 notch the timber above and push the beam up.

can you imagine 5 big guys couldn’t life it up. 

Edited May 21, 2023 by Nickfromwales
Attached File removed - sensitive information

[TonyT]

Your builders can hire lifting equipment, from most hire shops that make lifting heavy steel safe and manageable 

[BadgerBadger]

I feel for you, I really do.  It's a horrible feeling when you've identified a problem but haven't yet found the solution.  But try not to panic and just methodically work it through and Id be confident the end result won't be anywhere near as catastrophic as you fear it might.

 

Your SE sounds like he's responding and looking for solutions.  Try to focus on what is going to give you the best way forward on the project, as tempting as it can be I often find trying find blame for past mistakes doesn't actually help get them sorted. I see two initial steps...

 

1) Establish with SE if loadings on this beam are correct (i.e. if first floor mistake has been made)

2a) Assuming they are, talk with your builders about the best way to raise the beam as far as practical based on your SE's proposed options.

2b) If they're not, look realistically at how much re-specifying the beam is going to cost and decide if the extra headroom is worth it over 2a.

 

[Dave Jones]

just a heads up your steel drawing download has personally identifiable information. 

[Lofty718]

Sorry to hear you are going through this. Good advice and professionals at the design stage really are crutcial to a good building project. 

 

I think the people you have hired are all crap though, architect, builder, SE and 'project manager'

 

You will have to live with these decisions for a long time so make sure it's right. Consider using a different SE, there are options and solutions for everything. Your SE might be some bozo just punching numbers into a program and coming up with these huge beams.

[Sophiae]

2 hours ago, TonyT said:

Your builders can hire lifting equipment, from most hire shops that make lifting heavy steel safe and manageable 

They did. 2 Genie lifts. 

 

1 hour ago, Dave Jones said:

just a heads up your steel drawing download has personally identifiable information. 

Oh no. I’ll remove it now. I am so upset i didn’t realise it. 

[Sophiae]

1 hour ago, Dave Jones said:

just a heads up your steel drawing download has personally identifiable information. 

 

2 minutes ago, Sophiae said:

They did. 2 Genie lifts. 

 

Oh no. I’ll remove it now. I am so upset i didn’t realise it. 

I tried to remove it, it wasn’t possible 😞

[Gus Potter]

21 hours ago, Sophiae said:

I am in a very tight and extremely frustrating situation.

Feel for you.

 

Much will depend on just what stage of the work you are at. Seems like the beam B1 is in place but no extension roof?

 

I had a quick look at the extract of the calculations. I can't see page 7 but the loading used to design the beam looks about the right magnitude holding up a bungalow roof and the load from the flat extension roof. The mention of a second storey is probably just the SE maybe just calling the bungalow roof the second storey?

 

The beam is checked for at least three criteria. Strength checks.. moment capacity Mc 429.9 kNm, buckling strength Mb 145.9 kNm both of which are greater than the design moment applied to the beam = 121.5 kNm

 

Deflection is also checked against a limit of beam span / 360 = 19.6mm, calculated deflection is 10.883mm I get 10.9mm .. close enough.

 

However B1 has plates welded to the top and bottom flange which stiffens the beam quite a lot. Thus you would expect that the beam deflection would be less still and if it is less still why are they (the plates) there? One reason may be that the SE has decoupled the calculations and assumed that as the loads are not over the.. call it centre of gravity of the beam and we are only seeing part of the calculations. This eccentricity causes the beam to twist more and the SE may have designed the plates to resist this extra twisting and left the remainder of the beam to carry the other forces.

 

The main thing here is that I am not casting doubt on the SE's calculations but would ask out of curiosity if this is the reason for the plates. Also the plates are shown as the same width as the beam flange, nominally 173.2mm. To get the plate flush means cutting a long standard flat bar down lengthways.. more expensive and also if the plate is flush your standard fillet welds are not appropriate. You need to use partial penetration welds or similar which are more expensive. Normally I would use a standard 200mm wide plate which give loads of room for the standard fillet weld, especially as we know that not all beams / plates are truly straight. Again I would ask.. why was it done this way and are there other underlying reasons for this design approach that are not immediatly apparent.

 

Now this is really a mute point as the steel is paid for and B1 is in place.. other than it will let your SE know that you are now better informed. It is what it is. It's a great pity that neither the Architect or SE alerted you to this low height much earlier.

 

But what options might be available to raise the soffit of the beam. Well it could maybe go up quite a lot until the bottom is almost level or just above the ceiling of the extension. Here we would do a bit of joinery work to brace the existing roof trusses as we would be disrupting the joint between the existing roof ceiling joist and the rafter.

 

Turning to demolishing and rebuilding the supporting walls. Ideally we want to avoid this as these walls are probably offering sideways (lateral) support to other walls so when rebuilding you have the problem of re tying your new masonry into the old. In other words you risk making matters worse. Under the padstones the inside edge of the wall forming the sides of the opening can flap about and that will be bothering your SE. If you can live with it can you narrow the opening under B1 by say 100mm each side. What you could look at is either introducing some good solid timber posts fixed to the wall or maybe a couple of light steel channel sections, timber is cheeper. Now we have stopped the supporting wall from flapping about and they will carry a lot more load... which means they may not have to be demolished after all.

 

If the builder can give the SE the hand mixed recipe they used for the padstones and the concrete looks well compacted it will probably be the same strength as the existing brick and thus they could just stay in place and put another cut down lintel over the top once you lift the beam. That could be one solution worth exploring.

 

I would aim to keep on good terms with the SE , builder etc.. but start asking a few informed questions. It may be that your SE comes up with some good / other solutions.. free of charge in the interests of good will.

 

Hope this helps and things pan out ok for you.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

[Adsibob]

4 hours ago, TonyT said:

Your builders can hire lifting equipment, from most hire shops that make lifting heavy steel safe and manageable 

Yep. Commonly known as a genie lift, although other brands are also available.

[Sophiae]

1 hour ago, Gus Potter said:

Feel for you.

 

Much will depend on just what stage of the work you are at. Seems like the beam B1 is in place but no extension roof?

 

I had a quick look at the extract of the calculations. I can't see page 7 but the loading used to design the beam looks about the right magnitude holding up a bungalow roof and the load from the flat extension roof. The mention of a second storey is probably just the SE maybe just calling the bungalow roof the second storey?

 

The beam is checked for at least three criteria. Strength checks.. moment capacity Mc 429.9 kNm, buckling strength Mb 145.9 kNm both of which are greater than the design moment applied to the beam = 121.5 kNm

 

Deflection is also checked against a limit of beam span / 360 = 19.6mm, calculated deflection is 10.883mm I get 10.9mm .. close enough.

 

However B1 has plates welded to the top and bottom flange which stiffens the beam quite a lot. Thus you would expect that the beam deflection would be less still and if it is less still why are they (the plates) there? One reason may be that the SE has decoupled the calculations and assumed that as the loads are not over the.. call it centre of gravity of the beam and we are only seeing part of the calculations. This eccentricity causes the beam to twist more and the SE may have designed the plates to resist this extra twisting and left the remainder of the beam to carry the other forces.

 

The main thing here is that I am not casting doubt on the SE's calculations but would ask out of curiosity if this is the reason for the plates. Also the plates are shown as the same width as the beam flange, nominally 173.2mm. To get the plate flush means cutting a long standard flat bar down lengthways.. more expensive and also if the plate is flush your standard fillet welds are not appropriate. You need to use partial penetration welds or similar which are more expensive. Normally I would use a standard 200mm wide plate which give loads of room for the standard fillet weld, especially as we know that not all beams / plates are truly straight. Again I would ask.. why was it done this way and are there other underlying reasons for this design approach that are not immediatly apparent.

 

Now this is really a mute point as the steel is paid for and B1 is in place.. other than it will let your SE know that you are now better informed. It is what it is. It's a great pity that neither the Architect or SE alerted you to this low height much earlier.

 

But what options might be available to raise the soffit of the beam. Well it could maybe go up quite a lot until the bottom is almost level or just above the ceiling of the extension. Here we would do a bit of joinery work to brace the existing roof trusses as we would be disrupting the joint between the existing roof ceiling joist and the rafter.

 

Turning to demolishing and rebuilding the supporting walls. Ideally we want to avoid this as these walls are probably offering sideways (lateral) support to other walls so when rebuilding you have the problem of re tying your new masonry into the old. In other words you risk making matters worse. Under the padstones the inside edge of the wall forming the sides of the opening can flap about and that will be bothering your SE. If you can live with it can you narrow the opening under B1 by say 100mm each side. What you could look at is either introducing some good solid timber posts fixed to the wall or maybe a couple of light steel channel sections, timber is cheeper. Now we have stopped the supporting wall from flapping about and they will carry a lot more load... which means they may not have to be demolished after all.

 

If the builder can give the SE the hand mixed recipe they used for the padstones and the concrete looks well compacted it will probably be the same strength as the existing brick and thus they could just stay in place and put another cut down lintel over the top once you lift the beam. That could be one solution worth exploring.

 

I would aim to keep on good terms with the SE , builder etc.. but start asking a few informed questions. It may be that your SE comes up with some good / other solutions.. free of charge in the interests of good will.

 

Hope this helps and things pan out ok for you.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Thank you so much for taking the time to answer. 
I had a chat with another SE (friend’s husband) this morning. He agreed that SE will add a first floor in their calculations if the log is accessible. However he noted that the SE added more Block and Brick weight (doesn’t exist) which then gave him the much heavier load. 
whilst I understand I am not a specialist but surely you can’t assume what’s not there and then refuse to explain yourself. 

The SE has also miscalculated the total length of the beam and now it sits about 30cm longer on one side. Surely that defeats the purpose of balancing the weight. 
 

Unfortunately the SE is not on my side. The steel has cost me double the planned budget for it. Installing the steel has cost me double as the builders needed extra hands and tools on deck. They were not prepared for this much steel. 
The building has no irregularities to it. The loft is empty. 
I made it very clear that the budget is very tight and no future plans for expanding in any direction as there is no need for it. 
 

The builders want to charge extra thousands of pounds to lift the beam any higher as it is in excess of 550kg. They said the work on the needed to accommodate an extra 4cms isn’t worth it. 
 

The SE hasn’t offered to give me another design, his exact words were “I’ve given you the cheapest and everything else would me more expensive”. His solution was for me to negotiate my builders and reduce the £3K they’re asking. 
 

I didn’t understand a lot of your technical and scientific comments as I am mostly a visual person (neurodiverse) and find difficulty understanding things without diagrams. 
 

My frustration is beyond explaining to anyone. My heart is broken. I handed this task last year to a project manager who took money and all the new brick and block work has to go. I don’t know when is going to start. I have made it very clear, I have no issues taking anyone to civil court and point out major faults. 

I care for everyone I see at work. I treat them with dignity and respect. I spend time and go through the necessary information needed for them to make an informed decision. 
I expect everyone to do that same. 

We get complains all the time, we write statements and answer to our bosses, management and even our governing body. 
How is it that I am held accountable for all my actions, and the SE in my case needs to be petted? 
 

I feel so sad, so so sad. My son has missed out in joining a wonderful special needs school because of last year’s blunder and the way it’s going he will be missing out on joining this September too. He is going to year 3 and he still can’t do simple math addition. This is not fair. 

[Nickfromwales]

6 hours ago, Sophiae said:

 

I tried to remove it, it wasn’t possible 😞

Done.

[Nickfromwales]

@Sophiae

If you make any blunder posts, just 'report' it and a member of staff will pick it up ASAP  

[Pocster]

16 minutes ago, Nickfromwales said:

@Sophiae

If you make any blunder posts, just 'report' it and a member of staff will pick it up ASAP  

That work for me also ????

[Nickfromwales]

Just now, pocster said:

That work for me also ????

No, prob a ban would cut down the workload.

[Mr Punter]

I am not sure if it would be feasible to trim and modify the trusses and have them sit on the bottom flange of a steel beam so that the original ceiling height is maintained throughout?

[Sophiae]

5 hours ago, Mr Punter said:

I am not sure if it would be feasible to trim and modify the trusses and have them sit on the bottom flange of a steel beam so that the original ceiling height is maintained throughout?

I asked the builders, they want to charge me around £3K for that. They said the beam is way too heavy to work around it. It has to come down and they need 5 of them to be safe, then work on the trusses, then lift it up. I know they’re overcharging because they simply don’t want to do it. 

[Sophiae]

Can anyone see that he is calculating a whole new masonry floor rather than just the loft space? 

[TonyT]

To be honest your builders are pretty rubbish given the standard of work shown in the photos, so are pricing to not get the job, and if they do it’s been a high price that they know will make them a lot of money quickly- the term extras used to be a thing, price tight to get the job, client will always change their mind and this is the extras charged at a premium rate( generally good builders agree these rates before so you know mark up on materials, plant etc

 

best to stop get the job repriced and get some reputable trades that do care about doing a good job, they are out there but you will have to wait, anyone able to start pretty much short notice raises a red flag for me..

[Sophiae]

2 hours ago, TonyT said:

To be honest your builders are pretty rubbish given the standard of work shown in the photos, so are pricing to not get the job, and if they do it’s been a high price that they know will make them a lot of money quickly- the term extras used to be a thing, price tight to get the job, client will always change their mind and this is the extras charged at a premium rate( generally good builders agree these rates before so you know mark up on materials, plant etc

 

best to stop get the job repriced and get some reputable trades that do care about doing a good job, they are out there but you will have to wait, anyone able to start pretty much short notice raises a red flag for me..

Yes. They have been greedy because the terms were agreed for the build and it stated any alterations will incur extra charges to be decided by the kind of change. 
 

These are different builders. Last year’s work is all coming down. BCO said it has to go. 
 

These guys only came for the job of taking down the load bearing wall, prepare for and  installing the beam. 
I am doing a phased job due to finances. I just wanted to close the roof so I can move in. 

[TonyT]

1 hour ago, Sophiae said:

Yes. They have been greedy because the terms were agreed for the build and it stated any alterations will incur extra charges to be decided by the kind of change. 
 

These are different builders. Last year’s work is all coming down. BCO said it has to go. 
 

These guys only came for the job of taking down the load bearing wall, prepare for and  installing the beam. 
I am doing a phased job due to finances. I just wanted to close the roof so I can move in. 

I might be reading it wrong, but it’s not greedy to get paid for all the work you do, if the client messes up, changes their mind which affects the design, procurement and build of a project.  If the design team mess up and it’s not noticed, it’s not the builders fault.

 

that’s the joys of the building game, when it goes wrong everyone trying to apportion blame to everyone else and then add in procurement delays, client changes, general apathy  and clients then deciding to move the end date forward 2 months without discussion  all with builder/trades having to rejig workloads.

 

Thats why good builders are always busy cause they are managing some of this workload the make their own teams work easier.

[Temp]

Sorry if silly questions but.

 

Do you really need the opening to be so wide?  Reducing the span should reduce the depth of beam required.

 

Probably not a option but a post, pillar or chimney mid span should also reduce the depth. Double sided fireplace or aquarium?

 

 

[George]

14 hours ago, Sophiae said:

Can anyone see that he is calculating a whole new masonry floor rather than just the loft space? 

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

Edited May 22, 2023 by George

[Sophiae]

3 hours ago, TonyT said:

I might be reading it wrong, but it’s not greedy to get paid for all the work you do, if the client messes up, changes their mind which affects the design, procurement and build of a project.  If the design team mess up and it’s not noticed, it’s not the builders fault.

 

that’s the joys of the building game, when it goes wrong everyone trying to apportion blame to everyone else and then add in procurement delays, client changes, general apathy  and clients then deciding to move the end date forward 2 months without discussion  all with builder/trades having to rejig workloads.

 

Thats why good builders are always busy cause they are managing some of this workload the make their own teams work easier.

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. 
 

 

[Sophiae]

2 hours ago, Temp said:

Sorry if silly questions but.

 

Do you really need the opening to be so wide?  Reducing the span should reduce the depth of beam required.

 

Probably not a option but a post, pillar or chimney mid span should also reduce the depth. Double sided fireplace or aquarium?

 

 

The idea was to create the largest space possible for my disabled son to avoid bumping into walls, posts and taking trips to A&E. He lacks dangerous awareness so it’s something we are working with. 
I didn’t specify anything at all. All I asked for the widest possible span but with a head height of 2.1m so I may be able to add any doors in the future should a need arise for it. 
i left it with him to do the maths. I wasn’t consulted on the design or the span or the height or the width, nothing. He simply handed this and asked for him money to be transferred to the company to give me an original copy. 
He didn’t even explain what anything means. 
 

[Sophiae]

1 hour 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

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?