RSJ help?

[Kevrelf]

I've recently had a structural engineer draw up some plans for a rsj I want fitted. We're having a structural wall taken down between the kitchen and lounge. The wall is 3.4m and used to be the external wall to the house until a double storey extension was put on the side. The wall in question is a cavity wall made from standard construction.

After receiving the plans my builder has informed me that the rsj's suggested are far too large for the opening and will required more equipment and labour to fit, thus costing me more money. The drawings suggest using 2 254x146x37ub? Bolted together with steel plates welded top and bottom with the addition of 2 pillars built from engineered brick. But my builder whom has years of experience believes we'd require 2 rsj sizes of 203 without the addition of the engineered brick, and no welding of plates.

The engineer will not adjust his plans as he says everything he has calculated is correct by British structural standards. I'm a keen diyer and have renovated 1 flat and 1 house, but this job calls for experts, can anyone help? I can post drawings if required.

Thanks.

Kev

 

[tony1851]

Everything your SE has done is probably to British Standard blah blah blah, but that doesn't mean there aren't plenty of cheaper ways, with smaller beams and reduced piers.

Two UBs that size seem way over the top, and as for welding

There are many posts on this forum such as yours, where SEs have done over-the-top and unnecessarily costly designs. Some SEs do this to make the calculations easier for themselves, and also to cover themselves, but you as the consumer pay for all this nonesense.

You either do what he specifies, or find another, more practical SE to re-do the scheme, though of course you have to pay a second fee.

 

[Kevrelf]

Thanks tony, I'm thinking the most sane option is to use a SE that my builder recommends. The frustrating thing is the council have proved the plans as I had no reason to doubt them. I'll just have to see if the council are in a good mood and resubmit new drawings?

 

[jeds]

They are way over the top. I did one last week for a span a tad over 5 metres. Double beam. Standard brick/block cavity wall. Roof load, first floor load and a lean to roof load - so pretty much the most load you are likely to come across in a domestic situation. The beams are 2no 203x133x25 UBs bolted together at 600 centres. No welding, no plating.

 

[tony1851]

The frustrating thing is the council have proved the plans as I had no reason to doubt them. I'll just have to see if the council are in a good mood and resubmit new drawings?

That doesn't matter.
If you put new (smaller) beams in than those on the approved plans, the inspector will probably just ask you for the revised calcs. They will be checked by the council's engineer (again) and passed (again), assuming they are correct, of course.

 

[Kevrelf]

I how now received new calculations from a structural engineer that has been in the game for 20 odd years. The beams are much smaller than the original calculations and have been resubmitted to the council. Fingers crossed work will start next week.

Thanks for all your posts.

 

[tony1851]

The beams are much smaller than the original calculations and have been resubmitted to the council..

Good. As a matter of interest, what size has the latest engineer specified?