building control etc

[Owain]

I've got a full, bound, set of "The Knack" somewhere in the loft...

Owain

[Mike Halmarack]

You'll be needing to go to the uk.d-i-y newsgroup then. This is the uk.do-not.d-i-y newsgroup.

[Brian Sharrock]

> Full marks to Crawley BC for some commonsense advice.

Concur: but not-quite full marks for whoever wrote ;- " ... calculations to prove there adequacy." :)

[jon]

I've had a quick look on t'internet and a found a few sites, but these are mainly for installing 3 - 5 foot concrete lintels for doors, rather than rsjs, but they do show you how to use the acrows.

I also, like yourself, used to have an old Collins DIY book and remember seeing a section in there that covered this project, so I might buy the new

2006 copy as the old one did cover the topic fairly comprehensively.

However....if any kind soul knows of any good internet sites or could recommend any good books i'd be extremely grateful.

cheers

Jon

[Hugo Nebula]

On Mon, 02 Oct 2006 15:22:06 GMT, a particular chimpanzee named "Brian Sharrock" randomly hit the keyboard and produced:

Ejukation is not essential to be a BCO;-)

[Hugo Nebula]

On Mon, 02 Oct 2006 11:32:41 GMT, a particular chimpanzee named "jon" randomly hit the keyboard and produced:

I'm not being disparaging, but asking a BCO in a phone call, "what size RSJ do I need" is likely to elicit an arse-covering response. As Tony said, it depends on the experience of the BCO; if you'd have said to me, "I'm going to be using a 178 x 102 UB to support a uniformly distributed load over a 2.4m wide opening", I would have probably agreed that it would piss it (a technical term).

[Staffbull]

"I've got a full, bound, set of "The Knack" somewhere in the loft..."

thats going back some !!! I rmember the adverts for it

[Roger Mills]

No, they're not called "acros(so?)s"

The (so?) is a typo for (sp?) - indicating that the writer was unsure of the spelling, and is not part of the name. They are simply Acrow props - often abbreviated to Acros.

[cucumber]

Perhaps I'll scan a letter I received from my Bromley BCO and post it up (once I've finished my dealings with them!).

Very poor spelling, grammar, punctuation, formatting and some bits were corrected and added to with a pen after it was printed.

I haven't decided if I'm offended, amused or just plain scared that I'm going to be dealing with a complete idiot for the next month or so.

[Brian Sharrock]

Leaving the subject of BCOs' 'Ejukation' ... I was startled to see a headline in a London freebie newspaper - that a young girl was scanning on a bus. The headline stated 'Israel leaves UN ..." ( I thought, something along the lines of brown stuff and air circulating apparatus) newline) " ... to deal with Lebanon". There must have been a journalist, a sub-editor, editor ... involved? 'Edjukation'? ... things have only got better?

[thankyousam]

Yes, my apologies - I think I may have contributed to the confusion within this thread. It was meant to be (sp?) as I was unsure of the spelling of Acrow and I could not find anything when I searched for "acro".

I shall hide in a darkened room and learn to type correctly ;)

[jim]

Sorry to be butting in at this late stage but there's no stupid questions. Some of the most apparently inane questions posted on this newsgroup have generated the most profoundly insightful postings. We've all benefited : - ))

/snip/

No: most people who've followed an HNC/HND/degree engineering course should know (in theory) what calcs are needed.

or is it possible to obtain some

You can get the formulae from eng ref books, textbooks on structures - if you google for calcs on floor joists & the beams to hold them up on this group you'e sure to find enough pointers. Alternatively many RSJ suppliers will do the calcs for you for free on the basis they will supply the beam - just ask for a quote. The calcs are simple & you barely need a spreadsheet. What perhaps is wanted more is the ability to look at the calc result & then the structure & feel reasonably assured you've got the right answer. Or come back with the data below & see if this is your lucky day

You will need to assess the weight of masonry to be held up, and the weight (including imposed load) of that part of any floor or roof held up Remember the self weight of your beam has also to be taken into account. An SE would assess that for you. However if you d-i-y then you SHOULD diy BOTH the loading & the beam calcs (ie you need to understand and be confident in both aspects - don't put rubbish data into good formulae or vice versa) & preferably have someone look it over - also if possible look out for a comparable hole & compare.

BTW RSJ (Rolled Steel Joist) is mostly nowadays a colloquial term for any steel beam. Strictly it means just what it says - a joist rolled from a hot steel ingot in 1 piece in a steel mill. They have sloping internal profiles and are still obtainable, however most things called 'RSJ's are now Universal Beams. UBs are made by continuously welding steel plate & have the advantage of flat internal profiles.

But...do you really need a steel beam? A 6ft span is the width of many house windows & often all they have above them is a concrete beam. My guess is that 150(high) x 100 steel reinforced concrete beam will do your job (NB that's a guess which needs confirming) - perhaps even

75x100 might do. These are readily available from most heavyside builders merchants & cheaper than steel. You can cut them fairly easily with a stone cutting saw disc. As the builders merchant for an application sheet for more details. You might find a concrete beam easier to bond into an existing masonry wall.

Pros & cons: you can weld onto a steel beam, drill a hole through it with ease (if the drill is sharp) & tap it for a screw thread, whilst a concrete beam can really be only lightly drilled for wall plugs.

Finally you ought to inspect the supporting pillars for integrity - sound brick/blockwork & mortar? Any chance an abutting wall could displace either pillar in any direction once the opening is made? Is there enough foundation concrete under the pillars to accept the altered load profile?

When it comes to inserting the beam you must at all costs avoid progressive collapse of the brick/block layers above the opening. If soft lime mortar was used that is quite likely. You will need to support the bricks/blocks with short joist spars pushed through & supported by Acrow props. OTOH many houses were built in the 50s - 70s with hard cement mortar which holds blocks together like araldite and you won't need any additional support whilst you insert the beam - just don't let anyone jump on the flooor above ; - ) Actually, even if there is soft lime mortar you don't need great stout props - just making sure with a simple supporting frame that *NO* brick or block falls away is usually enough to keep the wall up for the duration.

HTH .

[jon]

Sorry Jim, only just came across this. Thanks for the very comprehensive reply. However the Mother-in-Law has changed her mind and decided not to knock through. Still some very usefull info if she changes her mind again, or for future googlers.

Jon