Crumbling front door step

[sarah68]

Hello,

I live in a Victorian terrace (I moved here fairly recently) with three steps up to the front door. When we moved here I noticed that the steps were uneven and had bits chipped out of them - not worn away with time, but chipped - but they seemed not to be wearing away any more. However, in the last few days I've noticed a small part of one of the steps has started crumbling - small chunks are coming off it and when you touch the area it's powdery and just comes away in your hand.

Can anyone tell me what is causing this - and more importantly of course, what I can do to stop it? I'd rather not replace the steps if possible as they are much nicer than a modern version would be.

Very many thanks,

Sarah

 

[Static]

What are the steps made from granite, concrete, metal, wood?

 

[sarah68]

Good question! I'd kind of assumed they were natural stone but thinking about it, I don't think stone would just crumble into powder - would it?

So I think they must be concete but they look like the original steps - (is this likely for a house built circa 1900? - sorry, I seem to be totally ignorant on this). But they do look more like concrete than granite!

 

[Static]

Hmm, photos may help. If it is concrete then depending on extent of damage there are ways to repair the edge of the step. If it is stone (sandstone or limestone maybe) then thats a little more complex.
When you say small chunks are breaking off and its powdery how large are the chunks? Are there signs of brown coppery stains around the areas breaking off?


Dont worry about seeming ignorant, if every knew the answers this place would be pointless.

 

[sarah68]

Hi,

I suppose by chunks I mean flakes - maybe the length of half a finger but quite thin, then if you rub them between your fingers they crumble to dust. Some of the chunks are a little 'fatter'.

I can't see any coppery stains but the steps were obviously once painted white (the paint has worn off) and all of the steps are now a bit grey and look a bit damp/mossy. It's kind of surprising that they would be damp as water would not collect in the area but dampness is the impression I get.

I can try to upload a photo later (though confess I have tried this before with another photo without success).

Very many thanks for your help!

 

[Glassman]

I had a few holes and large cracks in the garden wall to fill in over the weekend and I used an external grade polyfilla (for brickwork).
You apply it the same as you would normal poly-filla and when it dries it is as solid as concrete.

The point is, I noticed when reading the destructions on the back of the box that you can use this stuff to fill in voids in concrete steps.
Sounds like the stuff you need but if the there is signs of damp penetration as well you might have to damp-proof the step somehow afterwards?

 

[sarah68]

Hi,

Thankyou, that sounds promising! I'll have a look in my local DIY shop for the product.

I'd kind of wondered about damp proofing myself - or wondered if there's a product you can paint on concrete (stone?) to shield it from damp. But would that only protect it from future exposure to damp or would it solve the problem of the damp already in the concrete/stone? - if indeed it is damp that's the problem.

I'm also wondering why there would be damp unless the steps have been immersed in water - which seems impossible, there would have had to have been a major flood (and there hasn't!). Could damp be caused by the rain of the last 100 years?

Thanks everyone for all your help.

 

[Scrit]

Good question! I'd kind of assumed they were natural stone but thinking about it, I don't think stone would just crumble into powder - would it?

If it were sandstone (yellow or red) or limestone (white to light grey) it might well do. A combination of weather, polution and acid rain can play havoc with stonework. Acid rain can cause limestone to dissolcve over time. Which part of the UK are you in? The stone will almost certainly be local - if it is stone

So I think they must be concete but they look like the original steps - (is this likely for a house built circa 1900? - sorry, I seem to be totally ignorant on this). But they do look more like concrete than granite!

Modern concrete has been around since the 1870s (yes, I know the Romans used it to build the Colliseum....), so it might be concrete. But concrete generally wears better than stone. It will spall (i.e. flakes break off) but it generally still remains hard.

I'm also wondering why there would be damp unless the steps have been immersed in water - which seems impossible, there would have had to have been a major flood (and there hasn't!). Could damp be caused by the rain of the last 100 years?

The nature of many permeable rocks is that they will tend not to hold water, but in winter they can get wet then freeze overnight only to thaw in the morning. This freeze-thaw cycle repeated many times each winter over many years is responsible for natural erosion of permeable stone and is probably what your step has suffered from, in conjunction with the effects of acid rain. Either than replace the step with another stone one or cast a new concrete one in situ. The only other solution is normally to build a dam around the step and cast a new section in something like epoxy cement. You'll need some way to key-in this new section, such as steel bolts fixed into the old step, and you;'ll need to remove all the soft (rotten) stone - and this method of repair isn't always a success, especially if the stone below is badly degraded.

Scrit

 

[sarah68]

Hi,

Thankyou, that makes it all a bit clearer for me.

The steps are white/grey so could be limestone (I live in Northamptonshire). Frost damage sounds quite likely actually - some of the bricks on the top of the front wall are also quite chipped and I had previously wondered if they had been damaged by frost but not made the connection with the steps.

I guess this is a job too big for little old me so will be taking professional advice....... many thanks for your help!



I don't suppose anyone could give me any idea of the kind of cost I should be anticipating in replacing the steps? (there are three steps, by the way). Presumably a concrete version would be much cheaper than stone - less attractive though, I unfortunately!

Thanks again.

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