Is this RSJ safe?

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Hi all

I'm taking out (or rather my builder is!) part of the ground floor rear wall of a Victorian terrace in London, to create an opening to our new kitchen extension. Opening will be just under 2m wide. RSJ to be put in above new opening.

The issue is what's to the right of the opening: an internal wall of 10cm thickness. I thought we can widen some of that wall by 5cm (with steel, bricks cut to size?) to create a wide enough pier for the RSJ/padstone to rest on. However another, lower opening (former patio door!) is to the right of our new opening: it has a lintel over it, see blue bar below. I've consulted Building Control plus Structural engineer and not had a clear answer!

Do you think this will be safe?


Thanks!
 
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It looks ok to me. No need to widen the pier.

Ultimately though your engineer or building inspector will decide, and that is what matters.
 
For a two metre opening there should not be an issue with loads onto the existing wall. You should get the wall checked for capacity under the increased load and have an appropriately sized padstone installed if necessary, but as Woody says, gut feeling is that no pier is required.
 
Thanks guys. The structural engineer (well one in particular!) said I need 225mm bearings either side, and need to run the beam all the way over the patio doors/lintel too, making it more like 4 metres! That's overkill right?

Building control said for a 2m opening, they weren't so worried about bearings being wide (100mm one end, possibly 150mm other end depending on calcs was ok to them). They didn't comment on presence of adjacent patio door opening/lintel.

K
 
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Can you show that 3D model from the other side? The lack of edge lines and a grey cabinet (?) the same colour as the walls make it really hard to work out what's going on. Looks like an Escher drawing..[/list]
 
Curious as to what detail BC had to say a 2m opening. Looking at the drawing its more like the wall will be supporting loads the same as if it were "sort of a" 4m opening. What size steel has been specd? How much more cost is it to go the belts and braces route? i.e Beam across both openings.
 
Curious as to what detail BC had to say a 2m opening. Looking at the drawing its more like the wall will be supporting loads the same as if it were "sort of a" 4m opening. What size steel has been specd? How much more cost is it to go the belts and braces route? i.e Beam across both openings.

So: I described the situation to BC on the phone and that's what they said.

Re more like a 'sorta' 4m opening: I'm not sure how the patio door opening (i.e. extending not as high as a 'full' opening) factors into the load on that 10cm internal wall. Not sure cost of belt and braces route, it's also the thought of further disruptive work on an already big refurb and extension that's running late!
 
The issue here is whether or not the wall can take the load. You need an SE to check the capacity of the existing masonry for all of the load applied to it. It may or may not work.

The padstone can be as long as it needs to be to spread the load sufficiently, and then a check to determine the masonry capacity approx 1 metre down.
If it can be proven that the wall is OK, why spend money changing it?

Your SE may also be asked to check lateral stability depending on the circumstances but that is another matter.
 
Re: extending not as high as a 'full' opening

unless I'm mistaken the same causes "extra" load as it's carrying the brick above. The total load will then span at 2 points. So total load/2. will be applied to a) the continuation of the wall and b) the perpendicular wall.
You then add the load applied from above. What is above.. 1st floor joists. Purlins?? does the wall continue up? And then in the loft space what does it support?
Then you add the new loads imposed by the 2m opening.+++++

For you to consider BC opinion from a telephone convesation.. i.e no pics and no comeback is risky. Especially seeing the comments from an SE.

Best to just get an SE to do the calcs and not go with BC as (unless i'm mistaken) they wont pay out if all goes to pot as it is "advice". But make sure they quote on the lateral load aspect also.

I remember chatting to BC over the phone with regards our bungalow.. He said given the size of the property none of the internal walls were sufficiently load bearing to not be taken down.. the same was without considering ceiling joist spans or any other loads above.. to be honest whether it would hold up or not I dont really want to find out but my feeling is the joists would snap the roof cave in and the walls would just pop outwards. and what come back would I have on BC?
 
Hi all

Yep there's timber joists above, then a floor above and then the roof (it's a Victorian mid-terrace, two floors).

So irrespective of lateral load and loads above, the internal wall could take all the weight, if the area under the lintel & RSJ was built out into a suitable pier?

Ta
 
If 2 piers were designed to bear the weight of 10Tonnes and Steel to do the same then the wall in the middle would not have a part to play in the load bearing capacity.

It is all dependant on the loads from all directions. There is no point saying rrespective of lateral load and loads above as they all play part and a very important part in the choice of steel +++ .

Imagine we were not taking into account loads from above then a simple 2x1 timber would be sufficient to hold its own weight over that span. But obviosuly it wont work in your case because loads above 'have' to be taken into consideration.

What load and whether the wall can take it. depends on forces from above the brick type and no doubt many other things they SE's are trained to do. As RR says you need an SE to run calcs. Advice here is not sufficient to keep your home insurance valid if works are done on the basis of the same.

Personally and looking at the drawing again, i wouldnt want to include that middle wall in any supporting structure given it is at the end of the wall so the force could only spread in 1 direction.(although possibly a big enough pad stone could help spread sufficiently)

Really.... make a few calls to some SEs even PM RonnyRaygun as i think it's his field and you 'may' be in his area? and get some quotes for the calcs. I have basic knowledge of applied maths but wouldnt begin to anything similar done without Se Calcs.

Another example.. My mother wants to get opening kitchen diner.. All builders quote on straight steel. I look at drawings and flag an issue with proximity of steel to existing lintel/opening. Phone 5 Se's get quotes. All seemingly fair. Se comes along and confirms the issue with lintel and that 2 steels are needed. Clacs will be done as per quote. BC, Insurance and mum all happy. Had we not gone down that route. A new kitchen door would need to be put in because the lintel may have cracked & broken door. Cost for replacement door would be considerable more expensive than set of calcs.
With calcs you know what you should be getting with no hidden surprises. If even then it goeds wrong then the SE's insurance pays to remedy.

Get an SE.. in.
 
This is a common situation and not really a big deal in terms of the loading situation.
 
Yes. He could use a standard lintel and there would be no requirement for calculations.

Some councils will even pre-approve a certain size UB for common domestic situations with no need for calculations.
 
Yes. He could use a standard lintel and there would be no requirement for calculations.

Some councils will even pre-approve a certain size UB for common domestic situations with no need for calculations.
But...we do have 2m or so of the rear wall of the house, floor, ceiling, and roof (I'm assuming) being supported on the corner of a 100mm thick wall.

There is enough of the original rear wall remaining at ground floor level that lateral stability won't be an issue, but if the wall that the lintels are bearing onto is checked for capacity the masonry may well struggle...the OP might want to stick in a lintel and think no more about it, but thinking further a pier might well be required if calcs are done, especially considering that the wall is probably constructed from weak old Victorian masonry.
 

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