[Closed] knocking two into one rsj and supporting walls.

You need to get building control etc to approve that and they'll want all the calcs (from a structural engineer) to show the design is ok.

email me Im a civil engineer and do structural calcs for a living so would be happy to help;

alexander.lee@engineering dot com

^ this. Would be 'bad' if you got it wrong - [not free] professional advice needed.

good point guys. thanks.

Building control won't necessarily want calcs. Plenty of local authorities will accept a certain size rsj over a certain span without calcs

I suspect if you phoned up building control they could just tell you over the phone from your address. So many people knock rooms through that they must know the numbers for each house size off by heart...

I did a load of calcs for my mate's new build. The Council farmed the checking work out to another firm who couldn't understand my calcs. (I'd gone right back to basic formulae level as I thought that was what they required). Turned out they normally just plug the figures into a free program called "Supabeam". This was only basic beam deflection / stress stuff. 😕
Apparently they do usually go off tables.
I'm assuming these "nubs", as you call them, are tied in to the side walls ?

...what takisawa said and what are the nubs buillt on?

What he said. eg: you cant just build of the floor.

The nubs would have to have a suitable base. You're not gonna just be able to build in a RSJ without calcs. What span, and what load does it need to take. For your own safety I'd get the calcs done.

As above. What construction is downstairs floor? If timber obviously not strong enough, if original solid construction still probablynot strong enough. Also one major thing all the above have missed is piers will have to be "tied" into existing masonry. Also regarding upstairs wall are you sure it's built off the floor and not built between the joists?

When I had my wall taken out the engineer checked the attic out to see how much of the roof was loaded on the wall etc.

The spec he came up with meant they had to beef up the foundations for the pillars either side. So dig a bit down, pour in some more concrete (well the only concrete as being a Victorian house the wall just rests on a bit of rubble on top of the ground). They then capped the pillar off with engineering bricks and fitted the RSJ.

I used supabeam, but I have also built my own wheels. I wont do either again because someone practiced in the art can do it 20times quicker at a reasonable price.

I assume your tackling this as a DIY project...?

If you are few things to consider:

1) are foundations/ground conditions sufficient?
2) Nub sounds very vauge and not very substantial....how will it be tied to exisitng wall?
3) temporary works, how will you support your floor whilst demolishing exisitng wall?
4) Have you checked/notified your local planning office?

I could continue....

Best advice would be to consult a local structural engineer, he will advise you on beam and pier size and if needed for building control produce calcs in accordance with the up to date standards.

GOOD LUCK!!

1) are foundations/ground conditions sufficient?

front room is raised timber floor middle room is concrete.

so going to dig down 1m and make footings. to support the pillars

2) Nub sounds very vauge and not very substantial....how will it be tied to exisitng wall?

Nub [i]should have called it a pillar[/i] is going to be made of 1/2 block on flat ontop of the new footings
tied to existing walls with 3courses of engineering bricks as padstones. the rsj will be held in place with acrows while the padstones are built to get the tightest possible join. slate will be used to pack any gaps.

3) temporary works, how will you support your floor whilst demolishing exisitng wall?

4) Have you checked/notified your local planning office?

checked yes.
notified not yet. I want to see what sort of work it is to undertake single handed. all calcs will be done professionally.

Sounds like you've given a bit of thought to this which is good.

Im not sold on the 1/2 block pier (why not full on flat?) but thats a job for your S.E.

Try and blag yourself a copy of NHBC technical standards or similar, these have lots of rules of thumb and will ensure anything you do will be passed by building control, if you abide by it of course. These are pretty expensive, but some nice fellow might of put a downloadable version somewhere on the net if your lucky...which I obviously don't condone!!

But to be honest can't stress enough the value of having a S.E to come over have a look and knock out some calcs, shouldnt cost too much, but will be invaluable in the long run in terms of safety of the occupants and potential re sale value of the house.

make sure you get a cert for the RSJ as you 'could' have a nightmare if you ever sell.

make sure you get a cert for the RSJ as you 'could' have a nightmare if you ever sell.

BTW RSJ is old skool - they are all UBs now.

use roof slate for packing under rsj

All a buyer's solicitor would want to see if the building control certification for the work. You don't get a cert for the UBs / RSJs (I've just bought 6 of them and there was no paper work).

Is the wall above built off the floor boards?? If so thats a first on me.
Is the floor above one continuous joist over the two rooms or two separate floors bearing onto the wall below?
How are you tieing the nibs in to existing masonry?

We have brick walls upstairs built off the floorboards, they're not supporting walls though.

Oh and bare in mind the wall that you are taking down must go thro to ground therefore when you remove this part of the wall below the floor for your founds what will support your acros on the timber floor side?