Can you (would you) DIY an RSJ installation?

ChasingtheWelshdream

I seem to be on here a lot, with varying subjects - we are juggling a lot of plates so thanks for bearing with me :-)

We are putting an opening in a load bearing wall and have all the Structural Engineer's calculations.

We've been waiting for our chosen builder since May last year who had suggested March/April would be a good time - no problem, he has a very good reputation and we were happy to wait. However, he's making noises that he's still too busy and will be for the foreseeable future.

We are at the point where we can't really move forward with the rest of the downstairs until this opening is in place, and with no definite timescale from the builder (eg you're next in line, 2 months max etc), we're wondering what to do.

Obviously anyone reputable will be just as busy, and understandably so. But, we wondered if this was something that could actually be a DIY job? We've tackled most things, including making a new doorway with a standard concrete lintel, - as per the Engineer's calculations - and I understand the processes involved. But the word 'load bearing' scared us too much to consider this one.

Has anyone tackled anything like this themselves? Is it scary, or just simply a case of being methodical? Obviously Building Control will be involved and inspecting. This is the opening (followed by many pages of calculations, but essentially a 152 x 152 RSJ. The opening is 1.8m.

stuart45

It's a straight forward job normally. Is it just holding up floor joists, or is there a wall above it? As long as everything is correctly propped you should be fine. 1.8 is not that great a span.
Edit, looking at the plans properly it looks like it's not taking the joists.

ChasingtheWelshdream

Thanks for the reply,  it's not holding up joists, there is a wall above, but slightly offset (we had always thought it was a continuous wall to the roof before the Engineer measured up properly).

It's not a massive opening, but is holding up all the work around it. We are going to do all the finishing ourselves, it's just the RSJ that is holding things up.

The builder did say to call him again in a couple of weeks if he hasn't been in contact, so we're sort of hopeful that he might be able to give a proper timescale then. But if not, we need to think what to do, so just mulling things over. DH is very much 'its not in our skillset, the house might fall down'. I'm more - yeah, but if Building Control are inspecting, we'll have reassurance we've done it OK, and I'd rather not wait another year before a builder is available, we've held out nearly that long as it is.

As I say, just mulling....

phoebe1989seb

We've done it ourselves a three times working to our structural engineer's calculations.

The first time was back in the late 1990s when we were opening up the kitchen and adjoining *breakfast* room on the semi basement level of our detached Victorian house. That involved a large and smaller steel at right angles to each other. The large one was massive/extremely heavy and required several mates to assist DH with the lifting whilst my dad stood by giving instructions, lol!

In 2012 we had a large kitchen extension built on our Georgian thatched house and part DIYed it to save costs. Again DH fitted a massive steel (actually two, side by side due to the thickness/load bearing nature of the stone external wall) with the assistance of friends/a builder neighbour.

More recently we relocated the kitchen in our non-listed, 400 year old detached Welsh cottage (formerly a mill), which involved removing the wall between a large and small reception rooms as well as removing a chimney breast on the ground floor.

Again we worked to our structural engineer's calcs, ordering the steels as per his instructions. This time we called upon the services of the builders (father and son) who were on site at the time fixing a roof, to lend a hand with the lifting as we'd only just moved here and had no mates locally to ask....

Both RSJs were longer than yours, but apart from some juggling to get them into the building, the job was fairly straightforward. We also did all the prep work and the removal of walls afterwards.

As long as you're working to the structural engineer's calcs and have help with lifting, you should be ok.

We've got to tackle another one soon but DH now does property renovations/project management so has access to builder mates to lend a hand 😉

ChasingtheWelshdream

Thank you, that’s super helpful!

Mickey666

I've done it a few times.  In an outbuilding where I wanted to knock through a 1.5m opening in a brick wall,  I had an 8-inch I-beam laying around so used that.  Clearly well over-engineered for a wall that was only supporting the roof.

Then in the house, I knocked a wide doorway through a brick wall and used a 8x8-inch oak beam as a lintel and finally I replaced the bressumer of large inglenook fireplace that was badly decayed, though still holding up the top of the chimney breast.  The decayed bressumer was 3m long 9x6-inch oak so I replaced it with a 10x10-inch length of oak.  I figured if the previous bressumer had lasted a few hundred years then a larger one would last at least as long . . . . not that it will be my problem that far into the future

I had listed building consent for the changes but didn't bother with building regs or a structural engineer because it it perfectly obvious that the lintels are way over-engineered, as is the rest of the house . . . which is why it is still standing after 450 years, despite there being no building control or structural engineers back in those days.

The trickiest part of these sorts of jobs is to get the acrow-props in a position to provide adequate support while not getting in the way of inserting the new lintel.  For the inglenook fireplace I used "Strong Boy" supports as well as acrow-props and it took four of us to position the heavy new bressumer.

ChasingtheWelshdream

Thanks, that’s definitely encouraging. 

It looks like the lifting will be the main issue as we don’t really know anyone who could help, and all our neighbours are elderly. It would just be me and DH. 

How heavy are we talking? 

stuart45

About the same as one of  the old bags of cement, or 2 new ones. 50kg ish. Easily doable for 2 people. or 23kg per metre on the plans.

phoebe1989seb

ChasingtheWelshdream said:

Thanks, that’s definitely encouraging. 

It looks like the lifting will be the main issue as we don’t really know anyone who could help, and all our neighbours are elderly. It would just be me and DH. 

How heavy are we talking? 

Pretty heavy if we're talking RSJ, not catnic. 

Whereabouts are you, Chasing?

stuart45

When you say the wall above is offset, what is it sitting on? Do you know the construction and thickness of the wall above?

ChasingtheWelshdream

Mmm, I think I need to pop to the builders merchants with the spec and see.

When I got the concrete lintel and they carried it to my van telling me it was too heavy, I assumed it would be a two person job, but actually it was ok on my own. I can lift cement bags fine.

Phoebe, we’re mid-Wales, pretty much slap bang in the middle. Your Welsh house sounds lovely!

See, now I’m thinking that it could save us several hundred ££££ if the builder isn’t really that interested....