Advice needed - RSJ sitting on 3" of 4" brick with 5 ton load.

[rizla01]

The floor to my chalet above my lounge diner is the usual 7x3 slotted onto an 'I' beam spanning 11ft approx.

Above the RSj is a brick wall 8' x 11' approx tied into the inner skin of brick at one end and a section of brick wall coming off at approx 45deg at the other end. This in turn is straddling two floor joists which are above a solid single skin wall (with footings). I calculate the weight as being around 5 ton??

The house is around 50 yrs old and apart from what would appear to be a settlement crack in that agled section of wall, there are no problems, BUT when I exposed the end of the RSJ (Artex ceilings being replaced) I noticed that it is not even sitting on a whole brick and what appears tp just be a common fletton at that - not an engineering brick as i would have hoped for. Two courses below that brick (which is part of the wall ahead) there is a Concrete lintel.

At right angles to where the RSJ rests was a single skinned wall (Nothing above and running in the same direction as the joists BUT with footings)

My plan was to put a timber stud wall below the RSJ to separate the lounge, but to also insert a longer concrete lintel to enable me to move the door 12" away from the wall but having spotted the lintel support (or lack of) I am wondering how best to go about this.

Initially my thinking was to support the upper on Acrows and rebuild the bricks from below the lintel (There are cracks in couple of them), replace the lintel, stick an engineering brick beneath the RSJ. then rebuild a full brick pier, tied into the wall beneath the RSJ and at right angles to it along the line of the wall that was removed

Above the upstairs wall (which is a divider between two bedrooms), sits the A frame of the roof structure - in other words all joists & roof timbers run in the same direction - from front to rear.


I know the house has stood for a long time but pretty sure this would never pass regs today and house would prob be condemned till remedial work was carried out - or am I being a bit dramatic?

Perhaps if I doubled up on the 4x2 verticals on the stud-work bolting two together ith star washers it would be enough but this is just guesswork now.

Prob best to get a SE to cast an eye.

Any advice, or opinions most welcome.

 

[Bonni]

It's existing so nothing really needs to be done. As you say, it may not pass regs now as it should be on a concrete padstone, but it did pass regs in it's day. If you can be bothered to get a SE to spec current regs on it and fit a padstone, up to you, but I wouldn't be bothered unless theres some kind of major issue going on. It's likely the steel is probably not big enough to current regs because SE have gone overkill with steel sizes.

 

[rizla01]

Hi Bonni,

Thanks for replying.
I am mainly concerned as I need to extend the lintel below it.

If I replace the lintel the bricks above will go so it makes sense to put an engineering brick below the RSJ

Also I was thinking that 6 Acrow props (3x either side) would be sufficient to support RSJ whilst work is done.

Any thoughts?

 

[Bonni]

I would buy the shortage 6x4 concrete lintel and cut a short bit off to use as a padstone. I'm pretty sure engineering brick won't be to regs.

Depends what the acros sit on, is it a wooden floor. If you lay a scaffold board down across the joists (floor and ceiling) and acro off them, you should be fine. If you were taking out the full back wall of a house, I would lift some boards, hire longer acros and acro from the ground below floor level.

Just make sure that if you're extending the lintel below it, don't widen the gap so the RSJ above sits on a padstone that sits on some brick that sits on a part of the lintel with nothing below it. That's called point loading and you will need an SE. If the RSJ was bearing on the end of the lintel below which has brick/padstone directly below that, that's ok.

Not many people do, but building regs should be applied for for structural work. Also, waste pipes in bathrooms/en-suites require building regs if shortened/lengthened. But as I say, not many know and do that.

 

[rizla01]

Excellent.

Thanks for that Bonni. Sounds like I am ready to go.

Just a couple of things - yes the wooden floor joists are at 90 Deg to the RSJ and I will be using scaffold boards above & below.

I take it the 6x acrows plus one for the door widening will suffice?

Since I an only needing support at one end, how would you position the acrows? I was thinking 1 metre apart from the end I am working and as close as pos to the RSJ?

Shortage? Is that a mistype?

Brilliant suggestion re the concrete lintel. Just to be clear tho:-

If I read you correctly you suggest I cut a section off the NEW lintel and place that above the remainder of the new lintel spanning the doorway, as a padstone for the RSJ, using mortar above and under both, I assume. I.e. Sit new Lintel on Engineering brick padstone on mortar, add mortar on top, then lay padstone beneath RSJ with mortar between.

Is this correct?

 

[Bonni]

Sorry, shortest. You only need two 215mm lengths of 6x4 lintel as padstones. One to go under the steel where you've indicated (padstone with a brick under it to rest on the lintel below) and I would take that snapped brick out that you've highlighted where you want to put an engineering brick in, cut/drill the bricks below to take the two halfs out and put a 6x4 padstone there under the new concrete lintel. Always put some mortar in, never fit dry but you can also hammer slate in to pack the lintels and padstones.

As you can see, the brick snpped with the weight and an engineering brick would do the same.

6 acros is more than sufficient.

 

[rizla01]

Superb.
Thank you very much for taking the time to answer this one for me, Bonni. Lets hope I (and the house) survives Lol)

One thought, (also being a bit of a skinflint) would the older lintel not be harder than the new one?
Using that of course will prevent exposing the iron in the door lintel.

ALSO. always wondered

Using normal 3:1 mix for the mortar, how long after putting the bits together should I leave before removing the acrows?

I would normally have said 24 hours but because of the huge weights involved I wasn't sure.