Crumbling lintel - how to fix?

steveW

Hi

As you can see from the photo of the concrete lintel above our front door, it is crumbling.

What would be the best way to proceed? Get a builder in, presumably, but what would the likely advice be? Is replacing the lintel a big job?

steveW

This is the lintel!

F70

Don't think it is crumbling, looks more like a reaction to the paint that has been used, a good wire brush and proper masonry paint would solve that. 

That is what I can tell from the picture.

anselld

Unless I am missing something it looks like just cosmetic issues on the surface.  Seems OTT to replace lintel.

Scrape and fill surface scratches.  Repaint.  Repair messy pointing.

grumbler

What I see is some scratches and some paint peeling off. Unless I'm missing something, I don't see any structural problems.

ThisIsWeird

That's good news, Steve :-)

As said by others, that just looks like some surface erosion - there are no cracks or anything to suggest the lintel has 'failed'. These decorative cast lintels are quite soft - don't try pressure-washing them, for example.

I'd remove the paint - I guess with a heat gun - and gently clean the surface - you could try 80 grit paper on a flat block, but check that it's just sanding gently - you just want it clean. Brush off all loose dust.

You then decide whether to leave it like that, or to repaint it. For the latter, when it's bone dry, give it a darned good coat of Everbuild 406 Stabiliser. Brush it on and observe what happens. If it soaks in quickly, then apply further coats right away until this stops. Don't have it running with 406, but you do want to 'feed' it as much as it draws in. Then stop, and give it at least a day to dry.

Fill in any gouges using exterior filler such as Toupret, and try and blend in the texture - perhaps stipple with a brush?

Then masonry paint.

If, when you clean it up, you like the finish as it is - the sandstone - then it should be ok for years - it'll just continue to erode gently. There are treatments you can give it, but I don't know anything about them.

FreeBear

ThisIsWeird said: As said by others, that just looks like some surface erosion - there are no cracks or anything to suggest the lintel has 'failed'. These decorative cast lintels are quite soft - don't try pressure-washing them, for example.

But is it concrete ?

I'm not seeing any signs of aggregates, so suspect it might be a solid lump of stone (perhaps sandstone or gritstone). If it is indeed a soft(ish) stone, get rid of the paint and then use a tin of something more suitable - A silicate paint or lime wash rather than a Weathershield type paint.

ThisIsWeird

FreeBear said:

ThisIsWeird said: As said by others, that just looks like some surface erosion - there are no cracks or anything to suggest the lintel has 'failed'. These decorative cast lintels are quite soft - don't try pressure-washing them, for example.

But is it concrete ?

I'm not seeing any signs of aggregates, so suspect it might be a solid lump of stone (perhaps sandstone or gritstone). If it is indeed a soft(ish) stone, get rid of the paint and then use a tin of something more suitable - A silicate paint or lime wash rather than a Weathershield type paint.

Could be - no idea :-)

It just struck me as being too damaged - scarred and gouged - to be rescuable as a bare 'sandstone' feature, but it could well turn out ok with abit of work.

Anyhoo, the good news for Steve is that the lintel looks structurally ok.

stuart45

You also get some that are a 3 inch concrete lintel, with a couple of courses of brickwork on top, and then rendered to look like a stone lintel.

johnhenstock

That lintel is still good, nothing wrong with it.