Damaged reinforced concrete lintel - what to do?

[^woody^]

I look forward to Woodys answer to that with bated breath

It's a slab, not a beam and damage to small local areas do not affect the performance as a whole.

Slabs are wider

 

[Beginerz]

Quite agree no issue with rusty bars being surrounded in concrete as if dense/thick enough it will prevent further attack by moisture,more rust forming thus expanding thus spalling concrete with associated rust stains

Casts some question over whether it's going to be best to treat and patch with an epoxy cement product or leave rusty and surround with traditional cement?

 

[^woody^]

Whenever reinforced concrete is repaired, the steel must be cleaned, de-rusted, treated and then the concrete repaired.

 

[Dereekoo]

Casts some question over whether it's going to be best to treat and patch with an epoxy cement product or leave rusty and surround with traditional cement?

Doesn't really matter as the reinforcement in that area now offers nothing towards the structural integrity of the beam its all just a cosmetic exercise but something to be done with due diligence

 

[Dereekoo]

Slabs are wider

I have just invented the tee slab

 

[^woody^]

*Tee-beam.

I think you're a few centuries too late for the patent though.

 

[noseall]

*Tee-beam.

I've watched C beams glitter in the dark.

 

[Structural]

I totally agree with woody on all advises. And do cover the area so it doesn't get wet until you get to patch it up. It might be like this the last 30 years, but was covered by the conservatory and H2O +O2 is bad for steel. Make sure to lightly tap the area with a hammer to remove any loose concrete (if any) due to corrosion before the repair.

Good luck.

 

[Beginerz]

Whenever reinforced concrete is repaired, the steel must be cleaned, de-rusted, treated and then the concrete repaired.

I totally agree with woody on all advises. And do cover the area so it doesn't get wet until you get to patch it up. It might be like this the last 30 years, but was covered by the conservatory and H2O +O2 is bad for steel. Make sure to lightly tap the area with a hammer to remove any loose concrete (if any) due to corrosion before the repair.

Good luck.

Thank you. So is it a case of clean with a wire brush and remove the loose rust, then Jenolite? Does anything have to be done to the steel after the rust treatment has been applied and had time?

 

[Structural]

 

[PBSpears]

My view is that if it was going to fall down it would have happened by now.

The ends of beams are less stressed in bending than the middle so they can sustain some damage without problems. It's difficult to see from the photos but it seems that there is quite a width that is not damaged. It seems likely that the lintel is deeper further back.

If you aren't replacing the conservatory then you have to do a good job of the repair or will be noticeable and will make resale difficult. Fix the notch at the other end too and maybe paint the whole thing with epoxy paint.

What's behind the plastic/rubber flashing? If the brickwork just continues across then no problem, otherwise I need to know.

 

[Beginerz]

My view is that if it was going to fall down it would have happened by now.

The ends of beams are less stressed in bending than the middle so they can sustain some damage without problems. It's difficult to see from the photos but it seems that there is quite a width that is not damaged. It seems likely that the lintel is deeper further back.

If you aren't replacing the conservatory then you have to do a good job of the repair or will be noticeable and will make resale difficult. Fix the notch at the other end too and maybe paint the whole thing with epoxy paint.

What's behind the plastic/rubber flashing? If the brickwork just continues across then no problem, otherwise I need to know.

Hi there

Thank you for this. The slab runs all the way along next door's property as well (semi-detached) and I suspect it's probably one slab. So the damaged part which is close to ajoinong property may well actually be near the centre of the slab rather than the edge. Assuming it's one long slab of approx 12 metres spanning both houses which it looks like but I can't be certain of that.

The black flashing above is lead flashing with bricks beneath in the style of the rest of the house. The flashing was what was connected onto the conservatory roof prior to its removal.

On the photo below you will see that next door's part of the slab looks like it's been cut too and it's possible the steel reinforcement could be cut there too but it's hidden by flashing. Our house is on the left, the downpipe is the boundary and next door is to the right of that.

I do wonder whether a couple of helical bars fitted above within the pointing spanning over to next door might provide a long term reassurance here. Fitted by experts of course.

Whatever happens we are going to get a professional in even if it's just to repair the lintel in two places.

 

[Ivor Windybottom]

Does DIY exist any more? This website name's become a relic of a bygone era!

 

[Beginerz]

Does DIY exist any more? This website name's become a relic of a bygone era!

I think it's probably too much of an important job for me to attempt to have a go at and potentially muck up to be honest. Especially if messing up could make it difficult to re-sell as a poster above suggested and I wouldn't want to end up leaving some difficult bits of rust that might need removing and just covering up.

But the advice on what we may need to request from a tradesperson is invaluable.

 

[PBSpears]

I should have written that beams are stressed most in bending near the centre of the unsupported span. The amount of bending where the notch is will be small. Unless the your new bar(s) are welded to the existing one there will be no increase in overall structural integrity. I wouldn't try to put in new bars because I think it will compromise the repair to the concrete.

I am a retired structural engineer. i specialised in steel structures but the underlying principles of all structures are the same.