building control etc

[jon]

Apologies if this is a real common/stupid question, but,,

can someone please tell give me advice on the following.

I'm planning in knocking 2 rooms into one. The partition brick wall is approximately 8 foot wide, it is also a supporting wall. I would like to make the gap anywhere between 5 - 7 feet. I would therefore assume I would need an RSJ, at which point I would need a structural engineers report to calculate rsj size etc, and then I would also need to submit a building notice. I will be doing all the building work myself.

Questions:

Do I really need a structural engineer, or is it possible to obtain some piece of software that will calculate the correct rsj size etc at which point I can then submit the building notice myself.

If I do need a structural engineer, is there any work that I should do prior to him arriving, i.e. do I need to reveal the foundations where the supporting parts (ends) of the RSJ sit on the wall, etc.

cheers

Jon

[thankyousam]

Any decent builder should be able to calculate the weight of the wall above and purchase a suitable RSJ. We did a similar thing, knocking through our kitchen and back room. We submitted a building control notice, the inspector came out to check before the builder took the acros(so?) down and then will need to come back out again once the job has been fire proofed and finished off.

[daddyfreddy]

Submit the notice to your council and ask for a visit. Then you can ask the BC Officer what his minimum requirements will be for the RSJ.

[Peter Crosland]

Your best course is to talk to your local council's building control and ask them what they require. That way you should minimise the risk of doing the work and then having to alter it to suit their requirements. They will certainly want to see proper calculations regarding the RSJ.

Peter Crosland

[jon]

Cheers Peter, have already done this and they have said they do need proper calulations as submitted with building notice application and that this should be done by a structual engineer, which should cost approx £300.

Other people in this thread are saying this is not the case, and that a builder should be able to do this, are they wrong? I don't won't to get builders involved as i'll be doing all the work myself.

Jon

[jon]

I have already spoken to them and they have told me that I must submit the details of the RSJ to be used with the builbing notice apllication form.

Jon

[jon]

I'll be doing all the work myself, so I can't really do this, but are you saying that as long as the calculations are correct you don't need to be a structual engineer to work out/ provide the RSJ sizes, etc.

ps what's an acros(so?), also what needs to be fire proofed, the RSJ?

Jon

[thankyousam]

The Acro Jacks (sorry I can't find whether this is the proper spelling) are the adjustable supports that hold up the wall while the RSJ is being fitted. I suspect our builder got the RSJs off another job because they were massively oversized - the building control guy came in, took one look and said they looked oversized. He was in the house for less than a minute. I think they'd only ask to see your calculations if the RSJ looks too small. I know that doesn't help you calculate the correct size though :o)

[PSOE]

An acro is an Acrow Prop Stay, these hold the the wall up while the building work goes on around and at the end of the RSJ. If you didn't know that are you competent to do this work?

J

[jon]

Apologies I've always called them "strong boys", however I now know they're also called acros(so?)s

Jon

[Tony Bryer]

No, different LAs (and even different BCOs within the same LA) will take differing views: some always ask for calculations; others (generally older and more experienced) won't if the steel to be put it is obviously going to be OK. If your BCO will accept a 203x102 without calculations and headroom is not an issue, this will be cheaper than getting an engineer to justify the use of a smaller section.

[jon]

Cheers Tony, very helpful advice,

also just came across this, which should hopefully save me the £300 structual engineers fees:

[Lobster]

Erm no, that's something else.

Strongboy: Acrow:

David

[jon]

OK, point taken.

Jon

[Christian McArdle]

If you don't know the answers to these questions, then you should definitely NOT be doing the work. These questions also indicate that you don't know the answers to lots of other questions that you don't even know you need to ask.

I wouldn't dream of doing this myself, not least because it would be difficult to insure the work and the consequences of failure (total destruction of the property) are too severe. It is also usually quite cheap if you get them just to quote for the building work. It is the plastering and decorating that cost.

Christian.

[Tony Bryer]

marks to Crawley BC for some commonsense advice.

[Jim Alexander]

Well yes, and I too was worried by the Acrow knowledge, though in HSS they're not actually called Acrow, but least the OP hasn't (yet) criticised the criticism. Surely we can help.

that's fine if you don't fancy it, but I say I wouldn't dream of letting a cowboy builder do it, and how do you avoid a cowboy. By DIY perhaps?

err... never done that.

the point is the OP seems willing to be steered in the direction of BC compliance. Insureable when signed off.

Jim A

[Christian McArdle]

I meant insuring the work against collapse during the actual work, not whether the ensuing house is insurable.

I suppose your house insurance might cover it if you sledgehammer out a wall and the props are in the wrong place, but I'd want confirmation in advance.

Christian.

[jon]

Christian, I fully understand your point, and I would never dream of attempting this kind of work without obtaining all relevant knowledge of the whole procedure. Hence me coming onto this newsgroup to get as much info as possible, as well as contacting the Local Authority.

Hovever I fully believe this level of work is well within my scope.

As for employing builders, well just getting someone to turn up to give me a quote is proving to be nigh impossible.

Jon

[Clive George]

Some people are just more risk-averse than others. Christian is one of them.

Do you have a plan of what to do? Something like a decent DIY book covers it quite well - eg the Collins one. (awaits cries of 'no' from those with experience :-) )

cheers, clive