installing rsj

[roygbiv86]

my se has visited and gone away to do his calcs. can anyone give me a bit of advice on process and installing.
i am replacing existing timber beam supporting brick wall above with an rsj. span 3.7m

1) what is the process with building control. presumably i fill in some paperwork and send them the se calcs. do i then wait whilst they check the calcs and if so how long before i can start work typically
2) how many visits will bc need to make (so i know when to pause) and how much notice do i need to give them per visit
3) is it possible to prop up wall above from one side so it is easier to get new beam in place? or is that too unstable on wall above?
4) i think wall above has slightly dropped over the years by about 15mm at one end. should i try to lift this back up? or is that a daft idea? or is it even possible? (wall is 2.7m long and about 3m high - end furthest from outside wall has dropped)
5) is it possible to support existing beams whilst i remove bricks immediately below them and install the padstone? then when all is dry (how long?) remove existing beam and replace with new one?
thanks again for any advice, but as you can see i know nothing about this kind of work.

 

[noseall]

if the floor joists run onto the wall in question then you can prop the joists and this will hold the wall up above.

you can now remove the timber beam. if a few unstable bricks fall out, don't worry these can be put back later.

fit the new steel into position, then with an acro at each end, wind the beam up to the existing brick work. you can, provided the acros are sitting on solid ground, wind them up so that the press hard against the bricks above.

you can now fit any padstone arrangement to each end bearing and make good any fallen out bricks.

you can remove the acros after 24 hrs. in the mean time ring b.c and ask for a visit. give them a copy of the calcs when they arrive, and once inspected you can box in and plaster the beams.

 

[roygbiv86]

supporting existing wood beam is parallel to joists. and i hope to install rsj in the space between floor and ceiling. so i need to support wall above and replace existing wood joist with new rsj. also can i support wall from just one side?? thanks very much for any help

 

[joe-90]

Can you get 'Strongboy' wall supports in? They work in conjunction with acro props.

 

[noseall]

supporting existing wood beam is parallel to joists. and i hope to install rsj in the space between floor and ceiling. so i need to support wall above and replace existing wood joist with new rsj. also can i support wall from just one side?? thanks very much for any help

you will need to remove the upstairs skirting boards, and knock holes through the walls to allow 'needles' to run through and support the wall.
these needles will need to be at least 4 feet long so that they span a minimum of 2 joists each side of the wall.

it's a case of then supporting these joists below. it will be quite fiddly to replace any fallen bricks this way, you may have to do it from above.

 

[roygbiv86]

i literally know nothing so thanks to everyone

 

[gangman]

Hi roy
I do a lot of this type of structural work, fitting steels etc. and it's not as straight forward as some people think. I think you should have someone with experience in this type of work to have a look at it for you, even if it's only for advice.

It would be imposible to tell you how to fit this steel without being on site to check it first. There are so many variables to consider, such as the the condition of the wall, how it's tied in, how much deflection is on the bressemer, the safest way to support the wall when you take out the existing bresemer,etc.etc. I don't want to put you off but realistically this is not an easy diy job, fitting between joists is not the easiest of jobs.

There's a lot that can go badly wrong, it might be better to leave it to someone with experience and insurance.

If you want I'll give you a brief run down on how I'd tackle a job like this, it might help you decide.

Merry xmas.

 

[roygbiv86]

thanks for that advice. i have decided to get some builders with experience to do it. however, the first quote i have had is hideously expensive - £1600. so am trying to get another quote. problem is nobody wants to do it - all builders are busy and wont even quote let alone do it.!

 

[gangman]

I know £1600.00 sounds expensive but you normally get what you pay for. For a 4m steel holding up brickwork I start at about £1000 and add to that depend on the difficulty and time of the job. Builders not used to this type of work will normally price high to cover themselves.

At a guess, on your job, with two of my guys I'd look at two days for preparation and fitting the steel, leave for three or four days, then two days stripping out and making good. I think that would be a minimum, plus the time spent on a survey and I would be charging more than £1600

On this type of work the architect & S.E. I work with always recommend me because they know my standards, so ask your S.E. to recommend someone, he'll have seen the standard of work out there and he'll know who's good. Trust me don't go for someone cheap, you will have to pay for a job done right.

Best of luck, hope it goes well.

 

[roygbiv86]

you kindly offered to give a run down of how you would approach this job. if you can do that i would be grateful as i might consider doing some bits of it mayself that are not too difficult or dangerous in order to reduce costs. thanks agin .r

 

[^woody^]

I think that would be a minimum, plus the time spent on a survey and I would be charging more than £1600

and double

I think I had better up my prices. We (two of us) normally ask for less than a quarter of this (insert steels only - no making good), and I thought that was good for a days work.

No wonder I don't see many other builders when I am holidaying in Torquay.

To the OP, I would not give you any advice on doing this work, as if you are not experienced in this then IMO you should not tackle it. If you miss something, or something is slightly different about your property, or if something does not go according to plan, then you wil not know what to do.

If a support fails either whilst the work is in progress or once complete, it will fail quickly and without notice. I've done these for years, and I still worry about them.

 

[gangman]

Ok Roy
Without all the details it will be a bit of a general idea.

First support the upstairs wall, probably with needles as you're fitting between joists, the number and positioning of these depends on the wall. As it's now a wooden beam I would guess it's old brickwork, lime mortar, easier for cutting out for needles but it dosen't stay together as well. Plus you've said there's already some movement in the wall so for safety this stage has to be done right.

Once the wall is supported, put acrows under the existing beam, they are only there for support, not overtightened, that will lift the beam.

Next cut out for padstones, checking the existing brickwork. It might need remedial work or a new piers. I would probably use pre-cast padstones as they will allow more room for fitting the steel. They can be fitted after the steel is in place.

Next take out old beam and lift new steel into place.There are a lot of options on how this is done, it depends on the site. It's down to experience on the best way. Usually I'll do it manually with acrows or staging or just muscle, you can use lifting dollies but these I would keep for heavy steels.

We'll say that no bricks have fallen out, keeping it simple, we find the lowest point on the brickwork and put a 15mm wood packer on the steel at this point and jack the steel up level. You only jack the steel on the ends, never in the middle, and again not overtightening the acrows.

Bed the padstones on leaving 15mm between the top of the padstone and the steel, this is then packed with a semi dry mix, I use one part sharp sand to one part cement. If there's been a bit of work done under the padstone then this packing might be done the next day to allow for any shrinkage in the mortar. Then brick steel in on top of padstone.

We now pack between the top of the steel and the brickwork. I use a semi dry mix, three sharp to one cement. I don't mix it dry, I mix it wet and use it when it's drying out. I do it this way so there's less shrinkage in the mix. You can use an addetive called, I think, combex, I've used it but didn't find it any better. You find some builders pack the steel with bits of slate or brick, this is not the best way, it's just pressure points, which can alter with movment in the wall. I've seen lots of slate packing where the slate is easily pulled out, there's been movement and the pressure has altered. The best way is to pack it 100%, no gaps, and a cement mix will do this.

The 15mm wood packer is the tightest point on the steel, it's the minimum that you can easily fully pack. With a wooden beam there's normally a sag in the centre which will give a bigger gap towards the sides, if the brickwork was quite level I'd use a bigger packer, you need to make sure you fully pack this gap easily.
Leave the packer in place then get the mix in using trowels, fingers, whatever, and ram it tight with a small length of timber or your fingers. If you can get your hand up the back of the steel and push the mix into it tight from the front, it's easier, but it must be packed fully. Normally you would pack from below the steel but fitting between joists might mean doing it from above, which might mean floorboards up. You have to do whatever it takes to pack it properly.

When all the packing is done it's left for a few days to go off. Take out the wood packer on the steel and fill the gap. Take needles out one at a time and make good the holes, then lower the acrows on the steel slowly, you have to check there's no movement. Now make good on walls and ceiling.
There's so much more to consider, bricks that come loose, getting the steel into position, size of padstone etc. I've kept it simple as possible.

This is only to give you an idea of what's involved, I know the way in my head , I hope I've explained it enough for you.
The things you could look at doing are hacking off plaster so the builder an see what's involved, cutting holes for the needles, padstones etc. all the making good. Most builders will avoid decorating. You might help with the labouring and get something off the price.
Personally I would do it all myself, apart from maybe the decorating, that way it would be down to me if anything went wrong, and you might find most good structural builders will be the same. Sometimes you have to bite the bullet and pay the money, it's hard parting with your hard earned but there's high prices in the building game at the moment and it's attracting a lot off chancers. If any builders tell you that you don't need to pack fully between the steel and brickwork ie. use slate instead, then they will not be giving you a top notch job, for your money you want the best job, so try for that.

You now have some idea of what is involved and what to look for, hopefully you'll find a good builder at the right price.There are some really good builders out there, hope your S.E. can put you on to one.

Hope it goes well for you.

 

[gangman]

Woody
Looks like you are underpricing your work.

I pay my guys at least £100 per day, and I could work as a tradesman on site for £200 plus a day and not have any worries. My time and knowledge has to be paid for. I bet you're like me, come home from work and still worry about the job.
That sort of stress is taking time off your life and you should be paid for that.
Price on the quality of your work. Not on how good you think you are but on how good others know you are. If your work is good sell yourself on that not on price. Someone will always undercut you. If someone wants a cheap job let them get a cheap builder, know your own worth.

A couple of years ago my F in L quoted £2000 to cut double door opening in an internal wall, with rsj to take upstairs wall. The woman came back with a quote off a Polish builder of £100.
F in L has now quoted £10,000 to put the work right. There was no rsj just a length of 4x2 on its side.

By the way what's a holiday.

 

[noseall]

agree with gangman. you can either get a mate from the pub (polish or othrwise) for 100 sheets a pop, or pay a tradesman to take on the whole kit 'n' kaboodle, but this will come at a price.

£200 p/day is about right when pricing up man, van, tools, responsibility for the job and experience. in fact i think it is a bargain.

 

[roygbiv86]

yes i was hoping to find someone at about £200 per day. i was also hoping that if i did some work on the prep and making good then i could get the job down to 2 days so say 2 men for 2 days = £800. steel beam costs 150. so maybe i can get it done for about a £1000 all in - well plus cost of se and bc. thanks everyone and especially "gangman". much apppreciated.

final question to gangman on supporting existing wall above which is 2.7m long and tied into outside wall at one end and joins stud wall at the other. the wall is 2.8m high and half brick thick. how many needles would you use roughly. is each needle is supported at both ends by acros? also is there any point in trying to raise upstairs wall by the 3/4 inch it has dropped over the years? if so how? many thanks again