Supporting existing joists!

[andymason79]

At the house my wife and I have just bought, we are considering knockin

down an internal wall.

The joists 195 X 50 run from front to back and are 5.1 metres long They are supported at 3.6 metres buy a stone wall and carry on for th remaining 1.5 metres. The room behind is so small it seems pointless!

I figure that once the wall is removed (neither the wall nor floor i the room above (4.9 metres) carry any wall) that the joists will nee extra support! I do not want an unsightly catnic or steel on vie below. I am however considering an Oak beam (200 X 150 span 3 metres placed at ~2.5 metres, perpendicular to the joists, for support. figure I could place and fix the Oak beam before I remove the wall thus removing the need for props, or would I to hold the beam in plac till the masonry had set?

I am also considering cutting into the existing joist and placing a 19 X 74 joist at a right angle to the joists and using hangers and nails t fix them. Would this be adequate at the ~ 2.5 metre mark? Would I nee to bolt on pieces of timber (same size)? As I can't see how I can joi the joists in both sides without precise cutting, and then ther wouldn't be enough movement to fix the 195 X 74 into the wall or am wrong?

If I take the second option I will need props, and the ceiling wil move slightly, so I will probably have to renew it all! But then I wil be left with a hole where the wall was anyway!

But there will not be an unsightly beam of any description on vie below!

Does anyone have advice on how best to do this? How to do it? Has anyone done this before? What method is best?

Thanks

And

-- andymason79

[Sean Mc]

Speak to your councill building inspector. Get him out to have a look their usually a friendly bunch and will only to glad to help.

Sea

-- Sean Mc

[andymason79]

Cant really afford to pay the £600 they charge, that will pay for m new boiler!

Thank

-- andymason79

[Rob Morley]

You'll need to submit a Building Notice application anyway, so you're=20 going to have to pay for it whether you ask their advice or not. If you=20 don't ask them for advice you'll have to convince them that the solution=20 you choose is adequate, and advice you get from a newsgroup won't really=20 satisfy that requirement. Are you sure they're going to charge =A3600? I= =20 think the going rate around here is more like =A3300.

[Richard Faulkner]

In message , andymason79 writes

Get a structural engineer in to make some suggestions, do the calculations, and provide a drawing, (sketch probably).

If you dont get Building Control approval, you may have difficulty when you come to sell, (priceless ).

[Fash]

In my experience Building control are generally willing to give what might be termed "pre-application advice" at no charge and generally if you flatter them appropriately will suggest a solution that would satisfy them. There are still potential problems with this in that they are not structural engineers. It sounds to me like your suggestion with the cross joist is not likely to be strong enough. From what you say of the situation though losing the beam into the ceiling void doesn't sound like a big problem. I just carried out some work where I removed a load-bearing ground floor wall above which is the first floor loading, a brick wall and a second floor, and still have a flat ceiling. In my case I used 2 203mm universal beams welded together. The joists were then propped and cut back and the beam set up between the joists with the joists attached on steel hangers. You clearly need less than this, but going from 3.6m to 5m is a big deal if you're a piece of wood.

Ring the BCO up and see if he'll make an informal visit.

Fash

Richard Faulkner wrote:

[Fash]

In my experience Building control are generally willing to give what might be termed "pre-application advice" at no charge and generally if you flatter them appropriately will suggest a solution that would satisfy them. There are still potential problems with this in that they are not structural engineers. It sounds to me like your suggestion with the cross joist is not likely to be strong enough. From what you say of the situation though losing the beam into the ceiling void doesn't sound like a big problem. I just carried out some work where I removed a load-bearing ground floor wall above which is the first floor loading, a brick wall and a second floor, and still have a flat ceiling. In my case I used 2 203mm universal beams welded together. The joists were then propped and cut back and the beam set up between the joists with the joists attached on steel hangers. You clearly need less than this, but going from 3.6m to 5m is a big deal if you're a piece of wood.

Ring the BCO up and see if he'll make an informal visit.

Fash

Richard Faulkner wrote:

[Set Square]

I would echo what others have said about getting some free informal advice from your local BCO.

One solution which *may* be feasible is to strengthen the existing joists by bolting some steelwork to the sides of them - converting them into something akin to flitch beams which can span the full 5 metres without additional support. You'll need to take the ceiling down to do this - but you'll get a better job, with no patched-up bit where the wall is, by making a new continuous ceiling.

[andymason79]

This is a rough plan of what I am suggesting:

The internal wall is masonry

+------------------------------------------------------------------- |Filename: untitled.JPG |Download:

[andymason79]

Do you think that a 200 X 150 Oak beam placed below below the existin

joints, in the same location as the (proposed double 192 X 74) would b any better?

Am I completely wrong in the assumption that placing a jois perpendicular to the existing joists and hanging them from and nailin them to it reduces the span to ~ 2.9 and 2.1 metres

-- andymason79

[Richard Faulkner]

In message , andymason79 writes

Invalid filename??

[Sean Mc]

Most Inspectors will pop around for an informal chat, as long as te and biscuits are on offer:) £600 how did you get sum?

Could you not use an I Beam clad in oak?

Sea

-- Sean Mc

[Richard Faulkner]

In message , andymason79 writes

Andy,

You keep asking if your suggestions will be OK but, as nobody hear has yet claimed to be a structural engineer, or Building Control officer, "we" keep saying that you should get some advice.

Even if somebody were qualified, they would almost certainly say that they could not advise without seeing the job.

In the nicest way - why are you resisting professional advice? If you are in Manchester, the engineer I use will probably do what you need for around £200 +/-. He will also advise on the Building Regs. process if you want.

If you're not in Manchester, tell us where you are, and someone may be able to recommend.

[Set Square]

Or an I Beam at the same level as the joists - with the joists cut into it? You could then have a flat ceiling with nothing under it - but actually installing the I beam may present a challenge or two! Did you consider my earlier suggestion about flitch beams?

[andymason79]

Tell me more about how these flitch beams work?

I am reluctant to pay for an engineer and building regulations, becaus for what they would cost I could do most of the floor in RSJ?s!

Does anyone know where you can get 'T' Beams, like I beams but easie to install

-- andymason79

[Tony Bryer]

for the maths

has a picture

[Set Square]

See Tony Bryer's reply for the technical stuff.

A flitch beam is normally a thin steel beam sandwiched between two wooden beams. What I had in mind in your case was to sandwich each existing wooden beam between two steel beams by bolting steel to the sides - thus greatly increasing the strength and bending stiffness.

Maybe Tony could comment on whether this is feasible?

[Tony Bryer]

The problem with this is that a thin steel plate tends to buckle when bent. In a conventional flitch beam - plate between two decent bits of timber, all bolted together - this won't happen but when you put the plates on the outside it is much more likely and would need to be carefully checked by an engineer.

[owdman]

I'd take out the wall and then see how springy the floor feels. It's not going to collapse if the joists run through as you say. If too springy then add a beam centrally or 2 smaller ones at 1/3rd span.

cheers

Jacob

[andymason79]

Thank you,

A bit of common sense, The room the other side of the hall (lounge) ha exactly the same size joists and they span 5 metres. That ceiling/floo has been like that for 124 years so with a beam in the centre of th other room it would not be a problem.

The irony is all I keep hearing is regulation this and that.

And any Victorian or 1920's/30's house was build so much better tha any Bovis, Barratt, Meadgate or any of these S**T new homes with ther

1001 rules.

What matters is pride in how the tradesmen? do their job and th attitude now is B******s it in a fast as you can. Regulations are no always adhered to a lot of stuff gets covered up and is not done a required!

Ask yourself this would you want to buy a house built since 1950 whe it is 120 years old?

A lot of rules are stupid, they now require 300 mm of insulation i lofts, energy efficient boilers and double glazing, yet make peopl drill 110 mm holes straight through the wall for extractor fans therefore loosing a lot of the heat ?energy? they are trying to safe Why because they have blocked up most of the natural ventilation. It' highly contradictory!

Logic says if 8? (I would have preferred 10?) timber spans 16? for 125 years it can span 8? feet with support below!

Thank

-- andymason79