Foundation reinstated in one area

[Hornmeister68]

Hi, any advice would be appreciated.
Looking to get a wall knocked out between the kitchen and dining room (around 7 ft in length). It's load bearing.
The S/E has been and advised an RSJ (obviously) and an upright on one side (nearest the outer wall). He's advised to get the foundation reinforced where the upright will go.
My question is, how much am I looking at to get the foundation reinforced in that one area ?
Cheers in advance.
Ian

 

[tony1851]

Why on earth is there a steel post supporting the beam at the outer wall??

It's usual to sit the beam directly on a spreader on the wall itself, so that there is no concentrated load on the foundation, so avoiding a separate pad foundation for the post.
It also avoids the awkward pier you would be stuck with.
Seven ft is not a long span and the load will not be very high.

 

[noseall]

Why on earth is there a steel post supporting the beam at the outer wall??

A slender pier? A pier so slender it already occupies the end bearings of two lintels?

 

[Hornmeister68]

I don't know, thats what the s/e has proposed but the builder has questioned it too, telling us we just need the rsj

 

[tony1851]

A slender pier? A pier so slender it already occupies the end bearings of two lintels?

If that is the case, a competent SE could do the figures that would show it's no problem. Obviously we don't know the layout, but even if the kitchen door was right up against the dividing wall, there will still be sufficient wall remaining between that and the window in the adjacent room.
Even having the beam offset on the padstone would be OK (unless the wall is built of cardboard). The reaction from a 7ft-long beam will not be much.

 

[tony1851]

I don't know, thats what the s/e has proposed but the builder has questioned it too, telling us we just need the rsj

Can you post a copy of his figures (with your address deleted of course) so that we can see what the loading is?

 

[^woody^]

He's advised to get the foundation reinforced where the upright will go.

"Advised" is not the same as "specified". Which is it, as one is optional.

 

[Hornmeister68]

Firstly, apologies for my delay in replying, shift worker, just got up etc etc.

He's specified it (not advised). Also,the actual wall is just under 6 ft but theres a door opening next to it so the actual beam will be around 8ft actually.

Regarding his calculations, he's mailed with 9 attachments (around 30 pages), all which are bit crazy to understand. Don't want to post them all here but Ill give you the name hes entitles each attachment and if it makes sense to you, I'll then post the relevant attachmen.

As follows : All calcs for -
1. Reaction to floor span A3 B3
2. Beam A6B6
3. Masonry column at A5
4.Masonry bearing design at A5
5.Masonry bearing at B5
6. Masonry Panel to Rear
7. Beam A5 B5
8. Summary Sheets
9. His drawings

Hope this helps, I'll post whatever you advise out the above

Cheers

 

[tony1851]

Thirty pages - that's a novel, not structural calcs

3 and 9 would be interesting to see.....

 

[Hornmeister68]

Here's 3 pics of the area I'm talking about. The outside pic is where the builder would have to reinstate the foundation to support the upright although the builder has said we don't need an upright, just an RSJ ?????
(It seems like a lot of "ripping stuff up" just to get a wall knocked out between my kitchen and dining room)
By the way, the house was built in the 1950's, semi detached, brick construction, clay soil

 

[Hornmeister68]

Firstly, the Masonry Column at A5 pics

 

[Hornmeister68]

Here's his sketches. Apologies for some of the pics being blurry, let me know if you want me to repost. Also, the S/E writes like a doctor ;0)

 

[tony1851]

Not easy to see what's going on, but on a quick look two things stand out:

First, the brickwork appears to have been checked as a column rather than a wall (it is only treated as a column if its width is less than 4 x its thickness);
Second, no allowance appears to have been made for the stiffening effect of the outer skin, which considerably enhances strength.

The net effect of this is that the figures will under-estimate the strength of the wall; this is borne out by the last two lines of the
spreadsheet, which state:

"Design vertical load resistance DVLR = 60.29kN (in other words, the calculated strength)
"Applied factored vertical load V = 55kN.

The figures correctly include the loads transmitted from the roof and wall above, but even so, the figures clearly show that the applied load is less than the strength of the wall - and this is taking into account the considerable factors of safety (3.5 for materials, in this case).

The sketch showing the rear view with window and patio doors also shows that the openings are not excessive for the length of wall, and would comply with the relevant parts of the Building Regs.

There just doesn't seem to be any justification for a steel post in this position? - IMO just a good spreader would suffice.

 

[^woody^]

Looks like total BS to me. No need for a column and no need for reinforced foundations.

And TBH, I've never seen proper engineers write so much calculation.

 

[tony1851]

And TBH, I've never seen proper engineers write so much calculation.

The more they write - even if it's irrelevant or not strictly necessary - the more they can charge the client because it looks impressive.